PD-L2 variant immunomodulatory proteins and uses thereof

Information

  • Patent Grant
  • 11732022
  • Patent Number
    11,732,022
  • Date Filed
    Tuesday, March 13, 2018
    6 years ago
  • Date Issued
    Tuesday, August 22, 2023
    8 months ago
Abstract
Provided herein are immunomodulatory proteins comprising variant PD-L2 and nucleic acids encoding such proteins. The immunomodulatory proteins provide therapeutic utility for a variety of immunological and oncological conditions. Compositions and methods for making and using such proteins are provided.
Description
INCORPORATION BY REFERENCE OF SEQUENCE LISTING

The present application is being filed along with a Sequence Listing in electronic format. The Sequence Listing is provided as a file entitled 761612001500SeqList.txt, created Dec. 20, 2019 which is 3,353,515 bytes in size. The information in the electronic format of the Sequence Listing is incorporated by reference in its entirety.


FIELD

The present disclosure relates to therapeutic compositions for modulating immune response in the treatment of cancer and immunological diseases. In some aspects, the present disclosure relates to particular variants of PD-L2 that exhibit improved binding, such as improved binding affinity or selectivity, for one or more of the cognate binding partner proteins PD-1 and RGMb.


BACKGROUND

Modulation of the immune response by intervening in the processes that occur in the immunological synapse (IS) formed by and between antigen-presenting cells (APCs) or target cells and lymphocytes is of increasing medical interest. Mechanistically, cell surface proteins in the IS can involve the coordinated and often simultaneous interaction of multiple protein targets with a single protein to which they bind. IS interactions occur in close association with the junction of two cells, and a single protein in this structure can interact with both a protein on the same cell (cis) as well as a protein on the associated cell (trans), likely at the same time. Although therapeutics are known that can modulate the IS, improved therapeutics are needed. Provided are immunomodulatory proteins, including soluble proteins or transmembrane immunomodulatory proteins capable of being expressed on cells, that meet such needs.


SUMMARY

Provided herein is a variant PD-L2 polypeptide, containing an IgV domain or a specific binding fragment thereof, an IgC domain or a specific binding fragment thereof, or both, wherein the variant PD-L2 polypeptide contains one or more amino acid modifications in an unmodified PD-L2 or a specific binding fragment thereof corresponding to position(s) selected from 2, 12, 13, 15, 18, 20, 23, 24, 28, 31, 32, 33, 36, 37, 39, 44, 45, 46, 47, 48, 58, 59, 65, 67, 69, 71, 72, 73, 74, 75, 76, 77, 82, 85, 86, 89, or 91 with reference to numbering of SEQ ID NO:31. In some embodiments, the amino acid modification is an amino acid substitution, insertion or deletion.


In some embodiments, the unmodified PD-L2 is a mammalian PD-L2 or a specific binding fragment thereof. In some of any such embodiments, the unmodified PD-L2 is a human PD-L2 or a specific binding fragment thereof. In some of any such embodiments, the unmodified PD-L2 contains (i) the sequence of amino acids set forth in SEQ ID NO:31, (ii) a sequence of amino acids that has at least 95% sequence identity to SEQ ID NO:31; or (iii) a portion thereof containing an IgV domain or IgC domain or specific binding fragments thereof or both.


In some of any such embodiments, the specific binding fragment of the IgV domain or IgC domain has a length of at least 50, 60, 70, 80, 90, 100, 110 or more amino acids; or the specific binding fragment of the IgV domain contains a length that is at least 80% of the length of the IgV domain set forth as amino acids 24-130 of SEQ ID NO:4 and/or the specific binding fragment of the IgC domain contains a length that is at least 80% of the length of the IgC domain set forth as amino acids 122-203 of SEQ ID NO:4. In some of any such embodiments, the variant PD-L2 contains up to 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 amino acid modifications, optionally amino acid substitutions, insertions and/or deletions. In some of any such embodiments, the variant PD-L2 polypeptide contains a sequence of amino acids that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% sequence identity to SEQ ID NO:31 or a specific binding fragment thereof.


In some of any such embodiments, the variant PD-L2 polypeptide exhibits altered binding to the ectodomain of PD-1 or RGMb compared to the binding of the unmodified PD-L2. In some of any such embodiments, the variant PD-L2 polypeptide exhibits altered binding to the ectodomain of PD-1 compared to the unmodified PD-L2. In some aspects, the altered binding is altered binding affinity and/or altered binding selectivity.


In some of any such embodiments, the one or more amino acid modifications are selected from F2L, I12V, I13V, H15Q, N18D, N24S, C23S, G28V, N24D, V31A, V31M, N32D, L33P, L33H, L33F, I36V, T37A, S48C, S39I, E44D, N45S, D46E, T47A, E58G, E59G, K65R, S67L, H69L, P71S, Q72H, V73A, Q74R, V75G, R76G, D77N, Q82R, I85F, I86T, V89D, W91R, or a conservative amino acid substitution thereof. In some of any such embodiments, the one or more amino acid modifications are selected from among H15Q, N24D, E44D, V89D, Q82R/V89D, E59G/Q82R, S39I/V89D, S67L/V89D, S67L/I85F, S67L/I86T, H15Q/K65R, H15Q/Q72H/V89D, H15Q/S67L/R76G, H15Q/R76G/I85F, H15Q/T47A/Q82R, H15Q/Q82R/V89D, H15Q/C23S/I86T, H15Q/S39I/I86T, E44D/V89D/W91R, I13V/S67L/V89D, H15Q/S67L/I86T, I13V/H15Q/S67L/I86T, I13V/H15Q/E44D/V89D, I13V/S39I/E44D/Q82R/V89D, I13V/E44D/Q82R/V89D, I13V/Q72H/R76G/I86T, I13V/H15Q/R76G/I85F, H15Q/S39I/R76G/V89D, H15Q/S67L/R76G/I85F, H15Q/T47A/Q72H/R76G/I86T, H15Q/T47A/Q72H/R76G, I13V/H15Q/T47A/Q72H/R76G, H15Q/E44D/R76G/I85F, H15Q/S39I/S67L/V89D, H15Q/N32D/S67L/V89D, N32D/S67L/V89D, H15Q/S67L/Q72H/R76G/V89D, H15Q/Q72H/Q74R/R76G/I86T, G28V/Q72H/R76G/I86T, I13V/H15Q/S39I/E44D/S67L, E44D/S67L/Q72H/Q82R/V89D, H15Q/V89D, H15Q/T47A, I13V/H15Q/Q82R, I13V/H15Q/V89D, I13V/S67L/Q82R/V89D, I13V/H15Q/Q82R/V89D, H15Q/V31M/S67L/Q82R/V89D, I13V/H15Q/T47A/Q82R, I13V/H15Q/V31A/N45S/Q82R/V89D, H15Q/T47A/H69L/Q82R/V89D, I13V/H15Q/T47A/H69L/R76G/V89D, I12V/I13V/H15Q/T47A/Q82R/V89D, I13V/H15Q/R76G/D77N/Q82R/V89D, I13V/H15Q/T47A/R76G/V89D, I13V/H15Q/T47A/Q82R/V89D, I13V/H15Q/N24D/Q82R/V89D, I13V/H15Q/136V/T47A/S67L/V89D, H15Q/T47A/K65R/S67L/Q82R/V89D, H15Q/L33P/T47A/S67L/P71S/V89D, I13V/H15Q/Q72H/R76G/I86T, H15Q/T47A/S67L/Q82R/V89D, F2L/H15Q/D46E/T47A/Q72H/R76G/Q82R/V89D, I13V/H15Q/L33F/T47A/Q82R/V89D, I13V/H15Q/T47A/E58G/S67L/Q82R/V89D, H15Q/N24S/T47A/Q72H/R76G/V89D, I13V/H15Q/E44V/T47A/Q82R/V89D, H15Q/N18D/T47A/Q72H/V73A/R76G/I86T/V89D, I13V/H15Q/T37A/E44D/S48C/S67L/Q82R/V89D, H15Q/L33H/S67L/R76G/Q82R/V89D, I13V/H15Q/T47A/Q72H/R76G/I86T, H15Q/S39I/E44D/Q72H/V75G/R76G/Q82R/V89D, H15Q/T47A/S67L/R76G/Q82R/V89D, or I13V/H15Q/T47A/S67L/Q72H/R76G/Q82R/V89D.


In some of any such embodiments, the one or more amino acid substitutions correspond to position(s) selected from 13, 15, 39, 44, 47 67, 72, 76, 82, 85, 86, or 89. In some of any such embodiments, the one or more amino acid substitutions are selected from I13V, H15Q, E44D, T47A, S67L, Q72H, R76G, Q82R, I85F, I86T, V89D, or a conservative amino acid substitution thereof. In some of any such embodiments, the one or more amino acid substitutions correspond to position(s) selected from 13, 15, 44, 47, 67, 72, 76, 82, 86, or 89. In some of any such embodiments, the one or more amino acid substitutions are selected from I13V, H15Q, E44D, T47A, S67L, Q72H, R76G, Q82R, I86T, V89D, or a conservative amino acid substitution thereof.


In some embodiments, the variant PD-L2 polypeptide contains amino acid modifications I13V/H15Q, I13V/T47A, I13V/S67L, I13V/Q72H, I13V/Q72H, I13V/R76G, I13V/Q82R, I13V/I86T, I13V/V89D, H15Q/T47A, H15Q/S67L, H15Q/Q72H, H15Q/Q72H, H15Q/R76G, H15Q/Q82R, H15Q/I86T, H15Q/V89D, T47A/S67L, T47A/Q72H, T47A/Q72H, T47A/R76G, T47A/Q82R, T47A/I86T, T47A/V89D, S67L/Q72H, S67L/Q72H, S67L/R76G, S67L/Q82R, S67L/I86T, S67L/V89D, Q72H/R76G, Q72H/Q82R, Q72H/I86T, Q72H/V89D, R76G/Q82R, R76G/I86T, R76G/V89D, Q82R/I86T, Q82R/V89D or I86T/V89D. In some examples, the variant PD-L2 polypeptide contains amino acid modifications H15Q/S62L/Q82R, H15Q/S62L/V89D, H15Q/Q82R/V89D, or S62L/Q82R/V89D. In some instances, the variant PD-L2 polypeptide contains amino acid modifications H15Q/T47A/K65R/S67L/Q82R/V89D.


In some of any such embodiments, the variant PD-L2 polypeptide contains the IgV domain or a specific fragment thereof and the IgC domain or a specific fragment thereof. In some of any such embodiments, the variant PD-L2 polypeptide includes the sequence of amino acids set forth in any of SEQ ID NOS: 56-106, 108-114, 116-132 or a specific binding fragment thereof, or a sequence of amino acids that exhibits at least 95% sequence identity to any of SEQ ID NOS: 56-106, 108-114, 116-132 or a specific binding fragment thereof and that contains the one or more of the amino acid substitutions.


In some of any such embodiments, the variant PD-L2 polypeptide contains the IgV domain or a specific binding fragment thereof. In some of any such embodiments, the IgV domain or specific binding fragment thereof is the only PD-L2 portion of the variant PD-L2 polypeptide. In some of any such embodiments, the IgC domain or specific binding fragment thereof is the only PD-L2 portion of the variant PD-L2 polypeptide.


In some of any such embodiments, the variant PD-L2 polypeptide contains the sequence of amino acids set forth in any of SEQ ID NOS: 133-183, 185-191, 193-209, 268-318, 320-343 or a specific binding fragment thereof, a sequence of amino acids that exhibits at least 95% sequence identity to any of SEQ ID NOS: 133-183, 185-191, 193-209, 268-318, 320-343 or a specific binding fragment thereof and that contains the one or more of the amino acid substitutions. In some embodiments, the IgC domain or specific binding fragment thereof is the only PD-L2 portion of the variant PD-L2 polypeptide.


In some of any such embodiments, the variant PD-L2 polypeptide specifically binds to the ectodomain of PD-1 or RGMb with increased affinity compared to the binding of the unmodified PD-L2 to the ectodomain of PD-1 or RGMb. In some of any such embodiments, the variant PD-L2 polypeptide specifically binds to the ectodomain of PD-1 with increased affinity compared to binding of the unmodified PD-L2 to the ectodomain of PD-1. In some of any such embodiments, the variant PD-L2 polypeptide specifically binds to the ectodomain of PD-1 and the ectodomain of RGMb each with increased affinity compared to the binding of the unmodified PD-L2 to the ectodomain of PD-1 and the ectodomain of RGMb. In some of any such embodiments, the variant PD-L2 polypeptide specifically binds to the ectodomain of PD-1 with increased affinity and specifically binds to the ectodomain of the other of RGMb with decreased affinity compared to the binding of the unmodified PD-L2 to the ectodomain of the PD-1 or RGMb.


In some of any such embodiments, the increased affinity to the ectodomain of PD-1 is increased more than 1.2-fold, 1.5-fold, 2-fold, 3-fold, 4-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold, 20-fold, 30-fold, 40-fold, 50-fold or 60-fold compared to the unmodified PD-L2. In some embodiments, the increased affinity to the ectodomain of RGMb is increased more than 1.2-fold, 1.5-fold, 2-fold, 3-fold, 4-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold, 20-fold, 30-fold, 40-fold, 50-fold or 60-fold compared to the unmodified PD-L2. In some aspects, the decreased affinity to the ectodomain of RGMb is decreased more than 1.2-fold, 1.5-fold, 2-fold, 3-fold, 4-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold, 20-fold, 30-fold, 40-fold, 50-fold or 60-fold compared to the unmodified PD-L2.


In some of any such embodiments, the variant polypeptide specifically binds to the ectodomain of PD-1 with increased selectivity compared to the unmodified PD-L2. In some instances, the increased selectivity includes a greater ratio of binding of the variant polypeptide for PD-1 versus RGMb compared to the ratio of binding of the unmodified PD-L2 polypeptide for PD-1 versus RGMb. In some instances, the ratio is greater by at least or at least about 1.5-fold, 2.0-fold, 3.0-fold, 4.0-fold, 5.0-fold, 10-fold, 15-fold, 20-fold, 30-fold, 40-fold, 50-fold or more.


In some of any such embodiments, the PD-1 is a human PD-1. In some of any such embodiments, the RGMb is a human RGMb.


In some of any such embodiments, the binding activity is altered (increased or decreased) more than 1.2-fold, 1.5-fold, 2-fold, 3-fold, 4-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold, 20-fold, 30-fold 40-fold or 50-fold compared to the unmodified PD-L2.


In some of any such embodiments, the variant PD-L2 polypeptide is a soluble protein. In some embodiments, the variant PD-L2 polypeptide lacks the PD-L2 transmembrane domain and intracellular signaling domain; and/or the variant PD-L2 polypeptide is not capable of being expressed on the surface of a cell.


In some of any such embodiments, the variant PD-L2 polypeptide is linked to a multimerization domain. In some of any such embodiments, the variant PD-L2 polypeptide is a multimeric polypeptide, optionally a dimeric polypeptide, containing a first variant PD-L2 polypeptide linked to a multimerization domain and a second variant PD-L2 polypeptide linked to a multimerization domain. In some embodiments, the first variant PD-L2 polypeptide and the second variant PD-L2 polypeptide are the same or different.


In some of any such embodiments, the multimerization domain is an Fc domain or a variant thereof with reduced effector function. In some of any such embodiments, the variant PD-L2 polypeptide is linked to a moiety that increases biological half-life of the polypeptide. In some of any such embodiments, the variant PD-L2 polypeptide is linked to an Fc domain or a variant thereof with reduced effector function.


In some embodiments, the Fc domain is mammalian, optionally human; or the variant Fc domain contains one or more amino acid modifications compared to an unmodified Fc domain that is mammalian, optionally human. In some embodiments, the Fc domain or variant thereof contains the sequence of amino acids set forth in SEQ ID NO:211 or SEQ ID NO:212 or a sequence of amino acids that exhibits at least 85% sequence identity to SEQ ID NO:211 or SEQ ID NO:212. In some of any such embodiments, the Fc domain contains one or more amino acid modifications selected from among E233P, L234A, L234V, L235A, L235E, G236del, G237A, S267K, N297G, V302C, and K447del each by EU numbering. In some embodiments, the Fc domain contains the amino acid modification C220S by EU numbering. In some embodiments, the Fc domain contains the sequence of amino acids set forth in any of SEQ ID NOS: 1189, 1205, 1206, 1207, 1739, 1738, 1739, 1740 or a sequence of amino acids that exhibits at least 85% sequence identity to any of SEQ ID NOS: 1189, 1205, 1206, 1207, 1739, 1738, 1739, 1740 and exhibits reduced effector function.


In some of any such embodiments, the variant PD-L2 polypeptide is linked indirectly via a linker, optionally a G45 linker. In some of any such embodiments, the variant PD-L2 polypeptide is a transmembrane immunomodulatory protein further containing a transmembrane domain linked to the extracellular domain (ECD) or specific binding fragment thereof of the variant PD-L2 polypeptide. In some instances, the transmembrane domain contains the sequence of amino acids set forth as residues 221-241 of SEQ ID NO:4 or a functional variant thereof that exhibits at least 85% sequence identity to residues 221-241 of SEQ ID NO:4. In some embodiments, the variant PD-L2 polypeptide further contains a cytoplasmic signaling domain linked to the transmembrane domain. In some aspects, the cytoplasmic signaling domain includes the sequence of amino acids set forth as residues 242-273 of SEQ ID NO:4 or a functional variant thereof that exhibits at least 85% sequence identity to residues 242-273 of SEQ ID NO:4.


In some of any of the provided embodiments, the variant PD-L2 polypeptide modulates a response of an immune cell, such as a T cell. In some embodiments, the response, e.g. T cell response, is increased or is decreased. In some of any such embodiments, the variant PD-L2 increases IFN-gamma (interferon-gamma) expression relative to the unmodified PD-L2 in an in vitro T-cell assay. In some of any such embodiments, the variant PD-L2 decreases IFN-gamma (interferon-gamma) expression relative to the unmodified PD-L2 in an in vitro T-cell assay.


In some embodiments of any one of the variant PD-L2 polypeptides described herein, the variant PD-L2 polypeptide increases T cell signaling relative to the unmodified PD-L2 such as determined using a reporter assay involving a T cell (e.g. Jurkat) engineered with a reporter (e.g. luciferase) operably connected to an IL-2 promoter. In some embodiments of any one of the variant PD-L2 polypeptides described herein, the variant PD-L2 polypeptide decreases T cell signaling relative to the unmodified PD-L2, such as determined using a reporter assay involving a T cell (e.g. Jurkat) engineered with a reporter (e.g. luciferase) operably connected to an IL-2 promoter. In some of any such embodiments, the variant PD-L2 polypeptide is provided in any of a variety of formats, such as soluble or immobilized (e.g. plate-bound).


In some of any such embodiments, the variant PD-L2 polypeptide is deglycosylated.


Also provided is an immunomodulatory polypeptide containing the variant PD-L2 according to any of the provided embodiments linked, directly of indirectly via a linker, to a second polypeptide containing an immunoglobulin superfamily (IgSF) domain. In some cases, the IgSF domain is affinity modified and exhibits altered binding to one or more of its cognate binding partner(s) compared to the unmodified or wild-type IgSF domain. In some instances, the IgSF domain exhibits increased binding to one or more of its cognate binding partner(s) compared to the unmodified or wild-type IgSF domain to the same one or more cognate binding partner(s).


In some of any such embodiments, the variant PD-L2 is a first PD-L2 variant and the IgSF domain of the second polypeptide is an IgSF domain from a second variant PD-L2 of any of the provided embodiments, wherein the first and second PD-L2 variant are the same or different. In some embodiments, the variant PD-L2 polypeptide is capable of specifically binding to PD-1 or RGMb and the IgSF domain of the second polypeptide is capable of binding to a cognate binding partner other than one specifically bound by the PD-L2 variant polypeptide.


In some of any such embodiments, the IgSF domain is from a member of the B7 family. In some embodiments, the IgSF domain is a tumor-localizing moiety that binds to a ligand expressed on a tumor. In some cases, the ligand is B7H6. In some aspects, the IgSF domain is from NKp30.


In some of any such embodiments, the IgSF domain or affinity-modified IgSF domain thereof, optionally of the second or third polypeptide, is or contains an IgV domain. In some embodiments, the variant PD-L2 polypeptide is or contains an IgV domain. In some of any such embodiments, the immunomodulatory protein contains a multimerization domain linked to one or both of the variant PD-L2 polypeptide of the IgSF domain.


In some embodiments, the multimerization domain is an Fc domain or a variant thereof with reduced effector function. In some embodiments, the immunomodulatory protein is dimeric. In some cases, the immunomodulatory protein is homodimeric. In some instances, the immunomodulatory protein is heterodimeric.


In some of any such embodiments, the IgSF domain of the second polypeptide is an IgSF domain of a ligand that binds to an inhibitory receptor, or is an affinity-modified IgSF domain thereof. In some instances, the affinity-modified IgSF domain exhibits increased binding affinity and/or binding selectivity for the inhibitory receptor compared to binding of the unmodified IgSF domain to the same inhibitory receptor. In some embodiments, the inhibitory receptor is TIGIT or CTLA-4; or the ligand of the inhibitory receptor is CD155, CD112 or CD80.


In some of any such embodiments, the IgSF domain of the second polypeptide is an affinity-modified IgSF domain containing (i) a wildtype CD155 comprising an IgSF set forth in any of SEQ ID NOS: 47, 344, or 387, or a variant CD155 polypeptide comprising an IgSF domain of any of SEQ ID NOS set forth in Table 5, optionally any of the SEQ ID NOs: 345-386, 388-699, 1527-1736; (ii) a wildtype CD112 comprising an IgSF domain set forth in any of SEQ ID NOS: 48, 700, or 795, or a variant CD112 polypeptide comprising an IgSF domain of any of SEQ ID NOS set forth in Table 4, optionally any of the SEQ ID NOs: 701-794, 796-965, 1455-1526; (iii) a wildtype CD80 comprising an IgSF set forth in any of SEQ ID NOS:28, 1039, or 2039, or a variant CD80 polypeptide comprising an IgSF of any of SEQ ID NOS set forth in Table 3, optionally any of the SEQ ID NOs: 28, 966-998, 1000-1072, 1074-1146, 1147-1186; (iv) a wildtype PD-L1 comprising an IgSF set forth in any of SEQ ID NOS: 30, 1812, 1258, or 1454, or a variant PD-L1 polypeptide comprising an IgSF of any of SEQ ID NOS set forth in Table 8, optionally any of SEQ ID NOS: 1259-1453, 1743-1811, 1813-2021; (v) a sequence of amino acids that exhibits at least 95% sequence identity to any of the SEQ ID NOs in (i)-(iv) and that contains the amino acid substitution; or (vi) a specific binding fragment of any of (i)-(v).


In some embodiments, the immunomodulatory protein further contains a third polypeptide containing a wild-type IgSF domain or a variant or affinity-modified IgSF domain thereof, said affinity-modified IgSF domain comprising one or more amino acid modifications compared to the unmodified or wild-type IgSF domain of the IgSF family member, wherein the third polypeptide is the same as the first and/or second polypeptide; or the third polypeptide is different from the first and/or second polypeptide.


In some examples, the IgSF domain of the third polypeptide is an affinity-modified IgSF domain containing: (i) a wildtype CD155 comprising an IgSF set forth in any of SEQ ID NOS: 47, 344, or 387, or a variant CD155 polypeptide comprising an IgSF domain set forth in any of SEQ ID NOS: 345-386, 388-699, 1527-1736; (ii) a wildtype CD112 comprising an IgSF domain set forth in any of SEQ ID NOS: 48, 700, or 795, or a variant CD112 polypeptide comprising an IgSF domain set forth in any of SEQ ID NOS: 701-794, 796-965, 1455-1526; (iii) a wildtype CD80 comprising an IgSF set forth in any of SEQ ID NOS:28, 1039, or 2039, or a variant CD80 polypeptide comprising an IgSF domain set forth in any of SEQ ID NOS: 966-998, 1000-1038, 1040-1072, 1074-1112, 1114-1146, 1147-1186; (iv) a wildtype PD-L1 comprising an IgSF set forth in any of SEQ ID NOS: 30, 1812, 1258, or 1454, or a variant PD-L1 polypeptide comprising an IgSF domain set forth in any of SEQ ID NOS:1259-1453, 1743-1811, 1813-2021; (v) a sequence of amino acids that exhibits at least 95% sequence identity to any of the SEQ ID NOS in (i)-(iv) and that comprises the amino acid modifications, optionally amino acid substitutions, insertions and/or deletions thereof; or (vi) a specific binding fragment of any of (i)-(v).


In some of any such embodiments, the immunomodulatory protein further contains at least one additional polypeptide containing an IgSF domain of an IgSF family member or an affinity-modified IgSF domain thereof, said affinity-modified IgSF domain comprising one or more amino acid modifications compared to the binding of the unmodified or wild-type IgSF domain of the IgSF family member.


In some embodiments, the immunomodulatory protein further contains a multimerization domain linked to at least one of the variant PD-L2 polypeptide, the second polypeptide and/or the third polypeptide, optionally wherein the multimerization domain is an Fc domain or a variant thereof with reduced effector function.


In some embodiments, the multimerization domain promotes heterodimer formation.


Provided is an immunomodulatory protein containing a first variant PD-L2 polypeptide in which the multimerization domain is a first multimerization domain and a second variant PD-L2 polypeptide in which the multimerization domain is a second multimerization domain, wherein the first and second multimerization domains interact to form a multimer containing the first and second variant PD-L2 polypeptide, optionally wherein the first and second variant PD-L2 polypeptides are the same. Also provided is an immunomodulatory protein containing any of the provided immunomodulatory proteins, wherein the multimerization domain is a first multimerization domain and interacts with a second multimerization domain to form a multimer containing the immunomodulatory protein.


In some embodiments, the immunomodulatory protein is a first immunomodulatory protein and a second immunomodulatory protein is linked directly or indirectly via a linker to the second multimerization domain, wherein the multimer contains the first and second immunomodulatory protein. In some cases, the second immunomodulatory protein is an immunomodulatory protein as described herein and the multimerization domain is the second multimerization domain. In some embodiments, the multimer is a dimer. In some aspects, the immunomodulatory protein is a homodimer, optionally wherein the first and second multimerization domain is the same.


In some embodiments, the second polypeptide is a variant CD155 polypeptide and the first and/or second immunomodulatory protein includes the sequence set forth in any of SEQ ID NOS: 1191-1196, or a sequence of amino acids that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% sequence identity to any of SEQ ID NOS: 1191-1196. In some cases, the immunomodulatory protein is a heterodimer, optionally wherein the first and second multimerization domain are different and/or are capable of interacting to mediate heterodimer formation. In some examples, the second polypeptide is a variant CD155 polypeptide and: the first or second immunomodulatory protein contains the sequence set forth in any of SEQ ID NOS: 1197, 1198, 1199, 1200, 1201, 1203 or a sequence of amino acids that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% sequence identity to any of SEQ ID NOS: 1197, 1198, 1199, 1200, 1201 or 1203; and the other of the first or second immunomodulatory protein includes the sequence set forth in any of SEQ ID NOS: 1188, 1190, 1202 or 1204, or a sequence of amino acids that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% sequence identity to any of SEQ ID NOS: 1188, 1190, 1202 or 1204.


In some embodiments, the first and/or second multimerization domain is an Fc domain or a variant thereof with reduced effector function, optionally wherein the Fc domain is of an immunoglobulin protein that is human and/or the Fc region is human, optionally wherein the Fc region is of an immunoglobulin G1 (IgG1) or an immunoglobulin G2 (IgG2), optionally set forth in SEQ ID NO:211 or SEQ ID NO:212; or the variant Fc domain contains one or more amino acid substitutions in a wildtype Fc region, optionally wherein the reduced effector function is reduced compared to a wildtype Fc region, optionally wherein the wildtype human Fc is of human IgG1.


In some of any such embodiments, the first and second multimerization domain is the same or different. In some examples, the variant Fc region contains the amino acid substitutions E233P, L234A, L234V, L235A, L235E, G236del, G237A, S267K, or N297G, with residue numbering according to the EU index of Kabat; or the amino acid substitutions R292C/N297G/V302C or L234A/L235E/G237A, with residue numbering according to the EU index of Kabat. In some cases, the Fc region or variant Fc region contains the amino acid substitution C220S, with residue numbering according to the EU index of Kabat. In some examples, the Fc region or variant Fc region contains K447del, with residue numbering according to the EU index of Kabat.


In some of any such embodiments, the sequence of amino acids set forth in any of SEQ ID NOS: 1191-1204 or a sequence of amino acids that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% sequence identity to any of SEQ ID NOS: 1191-1204.


Also provided is a conjugate containing a variant PD-L2 according to any of the provided embodiments or an immunomodulatory polypeptide according to any of the provided embodiments linked to a moiety. In some cases, the moiety is a targeting moiety that specifically binds to a molecule on the surface of a cell. In some instances, the targeting moiety specifically binds to a molecule on the surface of an immune cell. In some embodiments, the immune cell is an antigen presenting cell or a lymphocyte.


In some cases, the targeting moiety is a tumor-localizing moiety that binds to a molecule on the surface of a tumor. In some of any such embodiments, the moiety is a protein, a peptide, nucleic acid, small molecule or nanoparticle. In some of any such embodiments, the moiety is an antibody or antigen-binding fragment. In some of any such embodiments, the conjugate is divalent, tetravalent, hexavalent or octavalent. In some cases, the conjugate is a fusion protein.


Also provided is a nucleic acid molecule(s) encoding a variant PD-L2 polypeptide according to any of the provided embodiments, a conjugate that is a fusion protein according to any of the provided embodiments, or an immunomodulatory polypeptide according to any of the provided embodiments. In some embodiments, the nucleic acid molecule is synthetic nucleic acid. In some instances, the nucleic acid molecule is cDNA.


Also provided is a vector containing the nucleic acid molecule according to any of the provided embodiments. In some cases, the vector is an expression vector. In some embodiments, the vector is a mammalian expression vector or a viral vector.


Also provided is a cell containing the vector of any of the provided embodiments. In some cases, the cell is a mammalian cell. In some aspect, the cell is a human cell.


Also provided is a method of producing a variant PD-L2 polypeptide or an immunomodulatory protein, including introducing the nucleic acid molecule according to any of the provided embodiments or vector according to any of the provided embodiments into a host cell under conditions to express the protein in the cell. In some cases, the method further includes isolating or purifying the variant PD-L2 polypeptide or immunomodulatory protein from the cell. Also provided is a method of engineering a cell expressing a variant PD-L2 variant polypeptide, including introducing a nucleic acid molecule encoding the variant PD-L2 polypeptide according to any of the provided embodiments into a host cell under conditions in which the polypeptide is expressed in the cell.


Also provided is an engineered cell, expressing the variant PD-L2 polypeptide according to any of the provided embodiments, a conjugate that is a fusion protein according to any of the provided embodiments, the immunomodulatory protein according to any of the provided embodiments, the nucleic acid molecule according to any of the provided embodiments, or the vector according to any of the embodiments.


In some cases the variant PD-L2 polypeptide or immunomodulatory protein contains a signal peptide. In some embodiments, the variant PD-L2 polypeptide or immunomodulatory protein does not contain a transmembrane domain and/or is not expressed on the surface of the cell. In some embodiments, the variant PD-L2 polypeptide or immunomodulatory protein is secreted or is capable of being secreted from the engineered cell. In some embodiments, the engineered cell contains a variant PD-L2 polypeptide that contains a transmembrane domain and/or is the transmembrane immunomodulatory protein according to any of the provided embodiments. In some embodiments, the variant PD-L2 polypeptide is expressed on the surface of the cell.


In some of any such embodiments, the cell is an immune cell. In some cases, the immune cell is an antigen presenting cell (APC) or a lymphocyte. In some embodiments, the engineered cell is a primary cell. In some embodiments, the cell is a mammalian cell. In some embodiments, the cell is a human cell. In some embodiments, the cell is a lymphocyte and the lymphocyte is a T cell. In some cases, the cell is an APC and the APC is an artificial APC. In some examples, the engineered cell is a primary cell. In some cases, the cell is a mammalian cell. In some instances, the cell is a human cell. In some embodiments, the engineered cell further contains a chimeric antigen receptor (CAR) or an engineered T-cell receptor.


Also provided is an infectious agent, containing a nucleic acid molecule encoding a variant PD-L2 polypeptide according to any of the provided embodiments or an immunomodulatory polypeptide according to any of the provided embodiments. In some cases, the encoded variant PD-L2 polypeptide or immunomodulatory polypeptide does not contain a transmembrane domain and/or is not expressed on the surface of a cell in which it is expressed. In some embodiments, the encoded variant PD-L2 polypeptide or immunomodulatory polypeptide is secreted from a cell in which it is expressed. In some cases, the encoded variant PD-L2 polypeptide contains a transmembrane domain. In some embodiments, the encoded variant PD-L2 polypeptide is expressed on the surface of a cell in which it is expressed.


In some of any such embodiments, the infectious agent is a bacterium or a virus. In some embodiments, the virus is a lentiviral or retroviral construct or a hybrid thereof. In some instances, the virus is an oncolytic virus. In some examples, the oncolytic virus is an adenovirus, adeno-associated virus, herpes virus, Herpes Simplex Virus, Vesticular Stomatic virus, Reovirus, Newcastle Disease virus, parvovirus, measles virus, vesticular stomatitis virus (VSV), Coxsackie virus or a Vaccinia virus. In some aspects, the virus specifically targets dendritic cells (DCs) and/or is dendritic cell-tropic. In some embodiments, the virus is a lentiviral vector that is pseudotyped with a modified Sindbis virus envelope product.


In some embodiments, the infectious agent further contains a nucleic acid molecule encoding a further gene product that results in death of a target cell or that can augment or boost an immune response. In some cases, the further gene product is selected from an anticancer agent, anti-metastatic agent, an antiangiogenic agent, an immunomodulatory molecule, an immune checkpoint inhibitor, an antibody, a cytokine, a growth factor, an antigen, a cytotoxic gene product, a pro-apoptotic gene product, an anti-apoptotic gene product, a cell matrix degradative gene, genes for tissue regeneration or a reprogramming human somatic cells to pluripotency.


Also provided is a pharmaceutical composition containing the variant PD-L2 polypeptide according to any of the provided embodiments, an immunomodulatory protein according to any of the provided embodiments, a conjugate according to any of the provided embodiments, or an engineered cell according to any of the provided embodiments. In some instances, the pharmaceutical composition contains a pharmaceutically acceptable excipient. In some embodiments, the pharmaceutical composition is sterile.


Also provided is an article of manufacture containing the pharmaceutical composition of according to any of the provided embodiments in a vial. In some cases, the vial is sealed.


Also provided is a kit containing the pharmaceutical composition according to any of the provided embodiments and instructions for use. Also provided is a kit containing the article of manufacture according to any of the provided embodiments and instructions for use.


Also provided is a method of modulating an immune response, such as increasing or decreasing an immune response in a subject including administering the pharmaceutical composition according to any of the provided embodiments to the subject. In some cases the method includes administering the engineered cells according to any of the provided embodiments. In some examples, the engineered cells are autologous to the subject. In some cases, the engineered cells are allogenic to the subject. In some embodiments, the method comprises administering to the subject a soluble variant PD-L2 polypeptide according to any one of the embodiments described herein, an immunomodulatory protein according to any one of the embodiments described herein or a conjugate according to any one of the embodiments described herein. In some embodiments, the method comprises administering to the subject an infectious agent encoding a variant PD-L2 polypeptide according to any one of the embodiments described herein.


In some embodiments, the method modulating the immune response treats a disease or condition in the subject.


In some of any such embodiments, the immune response is increased. Various formats of a variant PD-L2 polypeptide are contemplated for administration to a subject to increase an immune response, such as antagonist formats of a variant PD-L2. In some cases, such methods are carried out under conditions in which signaling by the inhibitory receptor PD-1 is blocked or attenuated by the administration. In some of any such embodiments, the method includes a variant PD-L2 polypeptide or immunomodulatory protein that is soluble is administered to the subject. In some instances, the soluble immunomodulatory protein is an immunomodulatory Fc fusion protein. In some embodiments of the method, a variant PD-L2 polypeptide according to any of the provided embodiments, or the immunomodulatory protein according to any of the provided embodiments is administered to the subject.


In some embodiments, an engineered cell containing a secretable variant PD-L2 polypeptide is administered to the subject. In some embodiments, an engineered cell according to any of the provided embodiments is administered to the subject. In some embodiments, an infectious agent encoding a variant PD-L2 polypeptide that is a secretable immunomodulatory protein is administered to the subject, optionally under conditions in which the infectious agent infects a tumor cell or immune cell and the secretable immunomodulatory protein is secreted from the infected cell.


In some of any such embodiments, the disease or condition is a tumor or cancer. In some embodiments, the disease or condition is selected from melanoma, lung cancer, bladder cancer, a hematological malignancy, liver cancer, brain cancer, renal cancer, breast cancer, pancreatic cancer, colorectal cancer, spleen cancer, prostate cancer, testicular cancer, ovarian cancer, uterine cancer, gastric carcinoma, a musculoskeletal cancer, a head and neck cancer, a gastrointestinal cancer, a germ cell cancer, or an endocrine and neuroendocrine cancer. In some of any such embodiments, the variant PD-L2 is administered in a format that increases an immune response in the subject.


In some of any such embodiments, the immune response is decreased. Various formats of a variant PD-L2 polypeptide are contemplated for administration to a subject to decrease an immune response, such as agonist formats of a variant PD-L2. In some cases, such methods are carried out under conditions in which signaling by the inhibitory receptor PD-1 is activated or stimulated or induced by the administration. In some embodiments, an immunomodulatory protein or conjugate comprising a variant PD-L2 polypeptide linked to an IgSF domain or a moiety that localizes to a cell or tissue of an inflammatory environment is administered to the subject. In some instances, the binding molecule contains an antibody or an antigen-binding fragment thereof or contains a wild-type IgSF domain or variant thereof.


In some embodiments, the immunomodulatory protein according to any of the provided embodiments or the conjugate according to any of the provided embodiments is administered to the subject. In some embodiments, a variant PD-L2 polypeptide that is a transmembrane immunomodulatory protein is administered to the subject. In some of any such embodiments, the engineered cell containing a variant PD-L2 polypeptide that is a transmembrane immunomodulatory protein according to any of the provided embodiments is administered to the subject. In some embodiments, an infectious agent encoding a variant PD-L2 polypeptide that is a transmembrane immunomodulatory protein is administered to the subject, optionally under conditions in which the infectious agent infects a tumor cell or immune cell and the transmembrane immunomodulatory protein is expressed on the surface of the infected cell.


In some of any such embodiments, the disease or condition is an inflammatory or autoimmune disease or condition. In some embodiments, the disease or condition is an antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis, a vasculitis, an autoimmune skin disease, transplantation, a Rheumatic disease, an inflammatory gastrointestinal disease, an inflammatory eye disease, an inflammatory neurological disease, an inflammatory pulmonary disease, an inflammatory endocrine disease, or an autoimmune hematological disease. In some embodiments, the disease or condition is selected from inflammatory bowel disease, transplant, Crohn's disease, ulcerative colitis, multiple sclerosis, asthma, rheumatoid arthritis, or psoriasis. In some of any such embodiments, the variant PD-L2 is administered in a format that decreases an immune response in the subject.





BRIEF DESCRIPTION OF THE DRAWINGS


FIG. 1A-1C depicts various formats of the provided variant IgSF domain molecules. FIG. 1A depicts soluble molecules, including: (1) a variant IgSF domain (vIgD) fused to an Fc chain; (2) a stack molecule containing a first variant IgSF domain (first vIgD) and a second IgSF domain, such as a second variant IgSF domain (second vIgD); (3) a tumor targeting IgSF molecule containing a first variant IgSF domain (vIgD) and an IgSF domain that targets to a tumor antigen, such as an NKp30 IgSF domain; and (4) a variant IgSF domain (vIgD) linked to an antibody (V-mAb). FIG. 1B depicts a transmembrane immunomodulatory protein (TIP) containing a variant IgSF domain (vIgD) expressed on the surface of a cell. In an exemplary embodiment, the cognate binding partner of the transmembrane bound vIgD is an inhibitory receptor (e.g. PD-1), and the TIP containing the vIgD (e.g. PD-L2 vIgD) antagonizes or blocks the negative signaling of the inhibitory receptor, thereby resulting in an activated T cell or effector T cell. In some cases, if clustering of the inhibitory receptor (PD-1) is proximal to an activating receptor (e.g. CD28) then agonizing activity by the TIP may be realized. FIG. 1C depicts a secreted immunomodulatory protein (SIP) in which a variant IgSF domain (vIgD) is secreted from a cell, such as a first T cell (e.g. CAR T cell). In an exemplary embodiment, the cognate binding partner of the secreted vIgD is an inhibitory receptor (e.g. PD-1), which can be expressed by the first cell (e.g. T cell, such as a CAR T cell) and/or on a second cell (e.g. T cell; either endogenous or engineered, such as a CAR T cell). Upon binding of the SIP with its cognate binding partner, the SIP antagonizes or blocks the negative signaling via the inhibitory receptor, thereby resulting in an activated T cell or effector T cell. In all cases, the vIgD can be a V-domain (IgV) only, the combination of the V-domain (IgV) and C-domain (IgC), including the entire extracellular domain (ECD), or any combination of Ig domains of the IgSF superfamily member.



FIG. 2 depicts an exemplary schematic of the activity of a variant IgSF domain (vIgD) fused to an Fc (vIgD-Fc) in which the vIgD is a variant of an IgSF domain of PD-L2. As shown, a soluble vIgD of PD-L2 interacts with its cognate binding partners to block interactions of PD-L1 or PD-L2 with PD-1, thereby blocking the PD-1 inhibitory receptor, and, in some cases, allowing the T cell to differentiate into an effector phenotype.



FIG. 3 depicts an exemplary schematic of a stack molecule that is a multi-target checkpoint antagonist containing a first variant IgSF domain (first vIgD) that is a PD-L1 or PD-L2 vIgD and a second IgSF domain (e.g. a second vIgD) that binds to a second inhibitory receptor. In the exemplary schematic, the second IgSF domain (e.g. second vIgD) is a CD112 or CD155 vIgD. As shown, the first vIgD and second vIgD interact with their cognate binding partners to block interactions of PD-L1 or PD-L2 with PD-1 and block interactions of CD155 or CD112 with TIGIT and/or CD112R, respectively, thereby blocking multiple inhibitory receptors.



FIG. 4 depicts an exemplary schematic of a stack molecule for localizing the variant IgSF (vIgD) to a tumor cell. In this format, the stack molecule contains a first variant IgSF domain (first vIgD) and a second IgSF domain (e.g. a second vIgD) in which the second IgSF domain (e.g a second vIgD) is a tumor-targeted IgSF domain that binds to a tumor antigen. An exemplary tumor-targeted IgSF domain is an IgSF domain of NKp30, which binds to the tumor antigen B7-H6. In this depiction, the first variant IgSF domain (vIgD) is a variant of an IgSF domain of PD-L2. As shown, binding of tumor-targeted IgSF domain to the surface of the tumor cell localizes the first variant IgSF domain on the tumor cell surface where it can interact with one or more of its cognate binding partners expressed on the surface of an adjacent immune cell (e.g. T cell) to antagonize inhibitory receptor signaling.



FIG. 5A depicts various exemplary configurations of a stack molecule containing a first variant IgSF domain (first vIgD) and a second IgSF domain, such as a second variant IgSF domain (second vIgD). As shown, the first vIgD and second IgSF domain are independently linked, directly or indirectly, to the N- or C-terminus of an Fc region. For generating a homodimeric Fc molecule, the Fc region is one that is capable of forming a homodimer with a matched Fc region by co-expression of the individual Fc regions in a cell. For generating a heterodimeric Fc molecule, the individual Fc regions contain mutations (e.g. “knob-into-hole” mutations in the CH3 domain), such that formation of the heterodimer is favored compared to homodimers when the individual Fc regions are co-expressed in a cell.



FIG. 5B depicts various exemplary configurations of a stack molecule containing a first variant IgSF domain (first vIgD), a second IgSF domain, such as a second variant IgSF domain (second vIgD), and a third IgSF domain, such as a third variant IgSF domain (third vIgD). As shown, the first vIgD, second IgSF, and third IgSF domains are independently linked, directly or indirectly, to the N- or C-terminus of an Fc region. For generating a homodimeric Fc molecule, the Fc region is one that is capable of forming a homodimer with a matched Fc region by co-expression of the individual Fc regions in a cell.



FIG. 6 depicts an exemplary schematic of the activity of a variant IgSF domain (vIgD)—conjugated to an antibody (V-Mab) in which the antibody (e.g. anti-HER2 antibody) binds to an antigen on the surface of the tumor cell to localize the vIgD to the cell. As shown, binding of the antibody to the surface of the tumor cell localizes the vIgD on the tumor cell surface where it can interact with one or more of its cognate binding partners expressed on the surface of an adjacent immune cell (e.g. T cell) to agonize or antagonize receptor signaling. In an exemplary embodiment as shown, the variant IgSF domain (vIgD) is a variant of an IgSF domain of PD-L2 that binds, such as has increased affinity for, the inhibitory receptor PD-1. Binding of the PD-L2 vIgD to the PD-1 inhibitory receptor antagonizes or blocks the negative signaling of the inhibitory receptor, thereby resulting in an activated T cell or effector T cell. In some cases, if clustering of the inhibitory receptor (PD-1) is proximal to an activating receptor (e.g. CD28) then agonizing of the inhibitory receptor activity by the TIP may be realized.



FIG. 7A-7C depicts various exemplary configurations of a variant IgSF-antibody conjugate (V-Mab). FIG. 7A shows various configurations in which a variant IgSF domain is linked, directly or indirectly, to the N- and/or C-terminus of the light chain of an antibody. FIG. 7B shows various configurations in which a variant IgSF domain is linked, directly or indirectly, to the N- and/or C-terminus of the heavy chain of an antibody. FIG. 7C depicts the results V-Mab configurations when a light chain of FIG. 7A and a heavy chain of FIG. 7B are co-expressed in a cell.



FIG. 8 depicts the MFI for binding to Jurakt/PD-1 cells at various concentrations of PD-L2 variant Fc fusion protein. Binding studies were carried out using Jurkat/IL-2 reporter cells that were then transduced to stably express PD-1 (Jurkat/PD-1). Cells were incubated with indicated concentrations of each candidate PD-L2 variant Fc fusion protein. As controls, a full extracellular domain of wild-type PD-L1 (“PDL1-FL”) and an IgV domain of wild-type PD-L2 (“wild type PD-L2 IgV”) or, anti-PD-1 monoclonal antibody (nivolumab), were tested. Unbound antibody was removed, bound antibody detected with fluorescently conjugated anti-human IgG, and the cells were analyzed by flow cytometry for MFI.



FIG. 9 and FIG. 10 depict the results for soluble variant PD-L2 IgV-Fc bioactivity tested in a human Mixed Lymphocyte Reaction (MLR). Approximately, 10,000 matured DC and 100,000 purified allogeneic CD4+ T cells were co-cultured with various increasing concentrations of variant PD-L2 IgV-Fc fusion proteins in 96 well round-bottom plates. Irrelevant human IgG or media only (designated “No Add”) were used as negative controls. As controls, either wildtype PDL2-Fc (full PD-L2 extracellular domain), wildtype PD-L2 IgV-Fc and or positive control anti-PD-1 monoclonal antibody (nivolumab) was assessed. IFN-gamma secretion in culture supernatants was analyzed and shown in FIG. 9 and FIG. 10.



FIG. 11A and FIG. 11B depicts the detection of PD-L2 SIP in supernatant of transduced CD19 CAR T cells and in HEK-293 cells, respectively.



FIG. 12A depicts the proliferation studies for T cells transduced with exemplary tested variant PD-L2 SIP. FIG. 12B depicts levels of IFN-gamma in the supernatant released by T cells transduced with exemplary tested variant PD-L2 SIP as measured by ELISA on day 5 after re-stimulation.





DETAILED DESCRIPTION

Provided herein are immunomodulatory proteins that are or comprise variants or mutants of Programmed cell death 1 ligand 2 (also known as PD-L2, PDCD1L2, PDCD1LG2, cluster of differentiation 273, CD273, or B7-DC) or specific binding fragments thereof that exhibit activity to bind to at least one target ligand cognate binding partner (also called counter-structure protein). In some embodiments, the variant PD-L2 polypeptides contain one or more amino acid modifications (e.g. amino acid substitutions, deletions or additions) compared to an unmodified or wild-type PD-L2 polypeptide. In some embodiments, the one or more amino acid modifications (e.g. substitutions) are in an IgSF domain (e.g. IgV) of an unmodified or wild-type PD-L2 polypeptide. In some embodiments, the variant PD-L2 polypeptide and immunomodulatory proteins exhibits altered, such as increased or decreased, binding activity or affinity for at least one cognate binding partner, such as at least one of PD-1 or RGMb. In some embodiments, the immunomodulatory proteins are soluble. In some embodiments, the immunomodulatory proteins are transmembrane immunomodulatory proteins capable of being expressed on the surface of cells. In some embodiments, also provided herein are one or more other immunomodulatory proteins that are conjugates or fusions containing a variant PD-L2 polypeptide provided herein and one or more other moiety or polypeptide.


In some embodiments, the variant PD-L2 polypeptides and immunomodulatory proteins modulate an immunological immune response, such as increase or decrease an immune response. In some embodiments, the variant PD-L2 polypeptides and immunomodulatory proteins provided herein can be used for the treatment of diseases or conditions that are associated with a dysregulated immune response.


In some embodiments, the provided variant PD-L2 polypeptides modulate T cell activation via interactions with costimulatory and/or coinhibitory signaling molecules. In general, antigen specific T-cell activation generally requires two distinct signals. The first signal is provided by the interaction of the T-cell receptor (TCR) with major histocompatibility complex (MHC) associated antigens present on antigen presenting cells (APCs). The second signal is costimulatory to TCR engagement and is necessary for T cell proliferation, differentiation and/or survival, including, in some cases, to avoid T-cell apoptosis or anergy.


In some embodiments, under normal physiological conditions, the T cell-mediated immune response is initiated by antigen recognition by the T cell receptor (TCR) and is regulated by a balance of co-stimulatory and inhibitory signals (e.g., immune checkpoint proteins). The immune system relies on immune checkpoints to prevent autoimmunity (i.e., self-tolerance) and to protect tissues from excessive damage during an immune response, for example during an attack against a pathogenic infection. In some cases, however, these immunomodulatory proteins can be dysregulated in diseases and conditions, including tumors, as a mechanism for evading the immune system.


In some embodiments, among known T-cell costimulatory receptors is Programmed cell death protein 1 or PD-1, which is the T-cell costimulatory receptor for the ligands PD-L1 (also known as cluster of differentiation 274, CD274. B7 homolog 1 or B7-H1) and PD-L2 (also known as PDCD1L2, PDCD1LG2, cluster of differentiation 273, CD273. or B7-DC). PD-L1 and PD-L2 are normally expressed on the surface of T cells, B cells, and myeloid cells. PD-L1 and PD-L2 are negative regulators of immune activation and are capable of down-modulating the immune response via interactions with programmed death 1 (PD-1) receptor. In some aspects, PD-1 is expressed on NK cells and T cells, including CD4+ and CD8+ T cells, whereby engagement of PD-1 can inhibit activation cell activation, proliferation, and/or expansion. However, PD-L2 ligands can also bind to Repulsive guidance molecule B or RGMb (also known as DRAGON or DRG11-responsive axonal guidance and outgrowth of neurite). The binding of PD-L2 to RGMb can block the interaction between PD-L2 and PD-1, and thereby potentiate or enhance the immune response. Thus, in some cases, interaction of PD-L2 with RGMb and PD-L2 with PD-1 yields opposing effects in modulating immune responses. Thus, PD-1 and RGMb may play opposing roles in immune responses to modulate pro-inflammatory or anti-inflammatory response, which, in some cases, are associated with a number of diseases and conditions.


In some embodiments, PD-1 and RGBb may play complementary roles in modeling an immune response. In some embodiments, enhancement or suppression of the activity of PD-1 receptor has clinical significance for treatment of inflammatory and autoimmune disorders, cancer, and viral infections. In some cases, however, therapies to intervene and alter the immunomodulatory effects of such receptors are constrained by the spatial orientation requirements as well as size limitations imposed by the confines of the immunological synapse. In some aspects, existing therapeutic drugs, including antibody drugs, may not be able to interact simultaneously with the multiple target proteins involved in modulating these interactions. In addition, in some cases, existing therapeutic drugs may only have the ability to antagonize but not agonize an immune response. Additionally, pharmacokinetic differences between drugs that independently target one of these receptors can create difficulties in properly maintaining a desired blood concentration of such drug combinations throughout the course of treatment.


In some embodiments, the provided variant PD-L2 polypeptides or immunomodulatory proteins modulate (e.g. increase or decrease) immunological activity associated PD-1. Thus, in some embodiments, the provided polypeptides overcome these constraints by providing variant PD-L2 with altered (e.g. increased or decreased) binding affinities to PD-1, thereby agonizing or antagonizing the effects of the receptor. In some embodiments, the provided polypeptides overcome these constraints by providing variant PD-L2 with altered (e.g. increased or decreased) binding affinities to RGMb, thereby modulating the effects of the interaction between PD-1 and PD-L2. Methods of making and using these variant PD-L2 are also provided.


All publications, including patents, patent applications scientific articles and databases, mentioned in this specification are herein incorporated by reference in their entirety for all purposes to the same extent as if each individual publication, including patent, patent application, scientific article or database, were specifically and individually indicated to be incorporated by reference. If a definition set forth herein is contrary to or otherwise inconsistent with a definition set forth in the patents, applications, published applications and other publications that are herein incorporated by reference, the definition set forth herein prevails over the definition that is incorporated herein by reference.


The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.


I. DEFINITIONS

Unless defined otherwise, all terms of art, notations and other technical and scientific terms or terminology used herein are intended to have the same meaning as is commonly understood by one of ordinary skill in the art to which the claimed subject matter pertains. In some cases, terms with commonly understood meanings are defined herein for clarity and/or for ready reference, and the inclusion of such definitions herein should not necessarily be construed to represent a substantial difference over what is generally understood in the art.


The terms used throughout this specification are defined as follows unless otherwise limited in specific instances. As used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms, acronyms, and abbreviations used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Unless indicated otherwise, abbreviations and symbols for chemical and biochemical names is per IUPAC-IUB nomenclature. Unless indicated otherwise, all numerical ranges are inclusive of the values defining the range as well as all integer values in-between.


The term “affinity modified” as used in the context of an immunoglobulin superfamily domain, means a mammalian immunoglobulin superfamily (IgSF) domain having an altered amino acid sequence (relative to the corresponding wild-type parental or unmodified IgSF domain) such that it has an increased or decreased binding affinity or avidity to at least one of its cognate binding partners (alternatively “counter-structures”) compared to the parental wild-type or unmodified (i.e., non-affinity modified) IgSF control domain. Included in this context is an affinity modified PD-L2 IgSF domain. In some embodiments, the affinity-modified IgSF domain can contain 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 or more amino acid differences, such as amino acid substitutions, in a wildtype or unmodified IgSF domain. An increase or decrease in binding affinity or avidity can be determined using well known binding assays such as flow cytometry. Larsen et al., American Journal of Transplantation, Vol 5: 443-453 (2005). See also, Linsley et al., Immunity, Vol 1(9): 793-801 (1994). An increase in a protein's binding affinity or avidity to its cognate binding partner(s) is to a value at least 10% greater than that of the wild-type IgSF domain control and in some embodiments, at least 20%, 30%, 40%, 50%, 100%, 200%, 300%, 500%, 1000%, 5000%, or 10000% greater than that of the wild-type IgSF domain control value. A decrease in a protein's binding affinity or avidity to at least one of its cognate binding partner is to a value no greater than 90% of the control but no less than 10% of the wild-type IgSF domain control value, and in some embodiments no greater than 80%, 70% 60%, 50%, 40%, 30%, or 20% but no less than 10% of the wild-type IgSF domain control value. An affinity-modified protein is altered in primary amino acid sequence by substitution, addition, or deletion of amino acid residues. The term “affinity modified IgSF domain” is not to be construed as imposing any condition for any particular starting composition or method by which the affinity-modified IgSF domain was created. Thus, the affinity modified IgSF domains of the present invention are not limited to wild type IgSF domains that are then transformed to an affinity modified IgSF domain by any particular process of affinity modification. An affinity modified IgSF domain polypeptide can, for example, be generated starting from wild type mammalian IgSF domain sequence information, then modeled in silico for binding to its cognate binding partner, and finally recombinantly or chemically synthesized to yield the affinity modified IgSF domain composition of matter. In but one alternative example, an affinity modified IgSF domain can be created by site-directed mutagenesis of a wild-type IgSF domain. Thus, affinity modified IgSF domain denotes a product and not necessarily a product produced by any given process. A variety of techniques including recombinant methods, chemical synthesis, or combinations thereof, may be employed.


The term “allogeneic” as used herein means a cell or tissue that is removed from one organism and then infused or adoptively transferred into a genetically dissimilar organism of the same species. In some embodiments of the invention, the species is murine or human.


The term “autologous” as used herein means a cell or tissue that is removed from the same organism to which it is later infused or adoptively transferred. An autologous cell or tissue can be altered by, for example, recombinant DNA methodologies, such that it is no longer genetically identical to the native cell or native tissue which is removed from the organism. For example, a native autologous T-cell can be genetically engineered by recombinant DNA techniques to become an autologous engineered cell expressing a transmembrane immunomodulatory protein and/or chimeric antigen receptor (CAR), which in some cases involves engineering a T-cell or TIL (tumor infiltrating lymphocyte). The engineered cells are then infused into a patient from which the native T-cell was isolated. In some embodiments, the organism is human or murine.


The terms “binding affinity,” and “binding avidity” as used herein means the specific binding affinity and specific binding avidity, respectively, of a protein for its counter-structure under specific binding conditions. In biochemical kinetics avidity refers to the accumulated strength of multiple affinities of individual non-covalent binding interactions, such as between PD-L2 and its counter-structures PD-1 and/or RGMb. As such, avidity is distinct from affinity, which describes the strength of a single interaction. An increase or attenuation in binding affinity of a variant PD-L2 containing an affinity modified PD-L2 IgSF domain to its counter-structure is determined relative to the binding affinity of the unmodified PD-L2, such as an unmodified PD-L2 containing the native or wild-type IgSF domain, such as IgV domain. Methods for determining binding affinity or avidity are known in art. See, for example, Larsen et al., American Journal of Transplantation, Vol 5: 443-453 (2005). In some embodiments, a variant PD-L2 of the invention (i.e. a PD-L2 protein containing an affinity modified IgSF domain) specifically binds to PD-1 and/or RGMb measured by flow cytometry with a binding affinity that yields a Mean Fluorescence Intensity (MFI) value at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% greater than a wild-type PD-L2 control in a binding assay.


The term “biological half-life” refers to the amount of time it takes for a substance, such as an immunomodulatory polypeptide comprising a variant PD-L2 of the present invention, to lose half of its pharmacologic or physiologic activity or concentration. Biological half-life can be affected by elimination, excretion, degradation (e.g., enzymatic) of the substance, or absorption and concentration in certain organs or tissues of the body. In some embodiments, biological half-life can be assessed by determining the time it takes for the blood plasma concentration of the substance to reach half its steady state level (“plasma half-life”). Conjugates that can be used to derivatize and increase the biological half-life of polypeptides of the invention are known in the art and include, but are not limited to, polyethylene glycol (PEG), hydroxyethyl starch (HES), XTEN (extended recombinant peptides; see, WO2013130683), human serum albumin (HSA), bovine serum albumin (BSA), lipids (acylation), and poly-Pro-Ala-Ser (PAS), polyglutamic acid (glutamylation).


The term “chimeric antigen receptor” or “CAR” as used herein refers to an artificial (i.e., man-made) transmembrane protein expressed on a mammalian cell comprising at least an ectodomain, a transmembrane, and an endodomain. Optionally, the CAR protein includes a “spacer” which covalently links the ectodomain to the transmembrane domain. A spacer is often a polypeptide linking the ectodomain to the transmembrane domain via peptide bonds. The CAR is typically expressed on a mammalian lymphocyte. In some embodiments, the CAR is expressed on a mammalian cell such as a T-cell or a tumor infiltrating lymphocyte (TIL). A CAR expressed on a T-cell is referred to herein as a “CAR T-cell” or “CAR-T.” In some embodiments the CAR-T is a T helper cell, a cytotoxic T-cell, a natural killer T-cell, a memory T-cell, a regulatory T-cell, or a gamma delta T-cell. When used clinically in, e.g. adoptive cell transfer, a CAR-T with antigen binding specificity to the patient's tumor is typically engineered to express on a T-cell obtained from the patient. The engineered T-cell expressing the CAR is then infused back into the patient. The CAR-T is thus often an autologous CAR-T although allogeneic CAR-T are included within the scope of the invention. The ectodomain of a CAR comprises an antigen binding region, such as an antibody or antigen binding fragment thereof (e.g. scFv), that specifically binds under physiological conditions with a target antigen, such as a tumor specific antigen. Upon specific binding a biochemical chain of events (i.e., signal transduction) results in modulation of the immunological activity of the CAR-T. Thus, for example, upon specific binding by the antigen binding region of the CAR-T to its target antigen can lead to changes in the immunological activity of the T-cell activity as reflected by changes in cytotoxicity, proliferation or cytokine production. Signal transduction upon CAR-T activation is achieved in some embodiments by the CD3-zeta chain (“CD3-z”) which is involved in signal transduction in native mammalian T-cells. CAR-Ts can further comprise multiple signaling domains such as CD28, 41BB or OX40, to further modulate immunomodulatory response of the T-cell. CD3-z comprises a conserved motif known as an immunoreceptor tyrosine-based activation motif (ITAM) which is involved in T-cell receptor signal transduction.


The term “collectively” or “collective” when used in reference to cytokine production induced by the presence of two or more variant PD-L2 of the invention in an in vitro assay, means the overall cytokine expression level irrespective of the cytokine production induced by individual variant PD-L2. In some embodiments, the cytokine being assayed is IFN-gamma, such as in an in vitro primary T-cell assay.


The term “cognate binding partner” (used interchangeably with “counter-structure”) in reference to a polypeptide, such as in reference to an IgSF domain of a variant PD-L2, refers to at least one molecule (typically a native mammalian protein) to which the referenced polypeptide specifically binds under specific binding conditions. In some aspects, a variant PD-L2 containing an affinity modified IgSF domain specifically binds to the counter-structure of the corresponding native or wildtype PD-L2 but with increased or attenuated affinity. A species of ligand recognized and specifically binding to its cognate receptor under specific binding conditions is an example of a counter-structure or cognate binding partner of that receptor. A “cognate cell surface binding partner” is a cognate binding partner expressed on a mammalian cell surface. A “cell surface molecular species” is a cognate binding partner of ligands of the immunological synapse (IS), expressed on and by cells, such as mammalian cells, forming the immunological synapse.


As used herein, “conjugate,” “conjugation” or grammatical variations thereof refers the joining or linking together of two or more compounds resulting in the formation of another compound, by any joining or linking methods known in the art. It can also refer to a compound which is generated by the joining or linking together two or more compounds. For example, a variant PD-L2 polypeptide linked directly or indirectly to one or more chemical moieties or polypeptide is an exemplary conjugate. Such conjugates include fusion proteins, those produced by chemical conjugates and those produced by any other methods.


The term “competitive binding” as used herein means that a protein is capable of specifically binding to at least two cognate binding partners but that specific binding of one cognate binding partner inhibits, such as prevents or precludes, simultaneous binding of the second cognate binding partner. Thus, in some cases, it is not possible for a protein to bind the two cognate binding partners at the same time. Generally, competitive binders contain the same or overlapping binding site for specific binding but this is not a requirement. In some embodiments, competitive binding causes a measurable inhibition (partial or complete) of specific binding of a protein to one of its cognate binding partner due to specific binding of a second cognate binding partner. A variety of methods are known to quantify competitive binding such as ELISA (enzyme linked immunosorbent assay) assays.


The term “conservative amino acid substitution” as used herein means an amino acid substitution in which an amino acid residue is substituted by another amino acid residue having a side chain R group with similar chemical properties (e.g., charge or hydrophobicity). Examples of groups of amino acids that have side chains with similar chemical properties include 1) aliphatic side chains: glycine, alanine, valine, leucine, and isoleucine; 2) aliphatic-hydroxyl side chains: serine and threonine; 3) amide-containing side chains: asparagine and glutamine; 4) aromatic side chains: phenylalanine, tyrosine, and tryptophan; 5) basic side chains: lysine, arginine, and histidine; 6) acidic side chains: aspartic acid and glutamic acid; and 7) sulfur-containing side chains: cysteine and methionine. Conservative amino acids substitution groups are: valine-leucine-isoleucine, phenylalanine-tyrosine, lysine-arginine, alanine-valine, glutamate-aspartate, and asparagine-glutamine.


The term, “corresponding to” with reference to positions of a protein, such as recitation that nucleotides or amino acid positions “correspond to” nucleotides or amino acid positions in a disclosed sequence, such as set forth in the Sequence listing, refers to nucleotides or amino acid positions identified upon alignment with the disclosed sequence based on structural sequence alignment or using a standard alignment algorithm, such as the GAP algorithm. For example, corresponding residues can be determined by alignment of a reference sequence with the sequence of wild-type PD-L2 set forth in SEQ ID NO:31 (ECD domain) or set forth in SEQ ID NO: 55 (IgV domain) by structural alignment methods as described herein. By aligning the sequences, one skilled in the art can identify corresponding residues, for example, using conserved and identical amino acid residues as guides.


The terms “decrease” or “attenuate” “or suppress” as used herein means to decrease by a statistically significant amount. A decrease can be at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100%.


The terms “derivatives” or “derivatized” refer to modification of a protein by covalently linking it, directly or indirectly, to a composition so as to alter such characteristics as biological half-life, bioavailability, immunogenicity, solubility, toxicity, potency, or efficacy while retaining or enhancing its therapeutic benefit. Derivatives of immunomodulatory polypeptides of the invention are within the scope of the invention and can be made by, for example, glycosylation, pegylation, lipidation, or Fc-fusion.


As used herein, “domain” (typically a sequence of three or more, generally 5 or 7 or more amino acids, such as 10 to 200 amino acid residues) refers to a portion of a molecule, such as a protein or encoding nucleic acid, that is structurally and/or functionally distinct from other portions of the molecule and is identifiable. For example, domains include those portions of a polypeptide chain that can form an independently folded structure within a protein made up of one or more structural motifs and/or that is recognized by virtue of a functional activity, such as binding activity. A protein can have one, or more than one, distinct domains. For example, a domain can be identified, defined or distinguished by homology of the primary sequence or structure to related family members, such as homology to motifs. In another example, a domain can be distinguished by its function, such as an ability to interact with a biomolecule, such as a cognate binding partner. A domain independently can exhibit a biological function or activity such that the domain independently or fused to another molecule can perform an activity, such as, for example binding. A domain can be a linear sequence of amino acids or a non-linear sequence of amino acids. Many polypeptides contain a plurality of domains. Such domains are known, and can be identified by those of skill in the art. For exemplification herein, definitions are provided, but it is understood that it is well within the skill in the art to recognize particular domains by name. If needed appropriate software can be employed to identify domains.


The term “ectodomain” as used herein refers to the region of a membrane protein, such as a transmembrane protein, that lies outside the vesicular membrane. Ectodomains often comprise binding domains that specifically bind to ligands or cell surface receptors, such as via a binding domain that specifically binds to the ligand or cell surface receptor. The ectodomain of a cellular transmembrane protein is alternately referred to as an extracellular domain.


The terms “effective amount” or “therapeutically effective amount” refer to a quantity and/or concentration of a therapeutic composition of the invention, including a protein composition or cell composition, that when administered ex vivo (by contact with a cell from a patient) or in vivo (by administration into a patient) either alone (i.e., as a monotherapy) or in combination with additional therapeutic agents, yields a statistically significant decrease in disease progression as, for example, by ameliorating or eliminating symptoms and/or the cause of the disease. An effective amount may be an amount that relieves, lessens, or alleviates at least one symptom or biological response or effect associated with a disease or disorder, prevents progression of the disease or disorder, or improves physical functioning of the patient. In the case of cell therapy, the effective amount is an effective dose or number of cells administered to a patient by adoptive cell therapy. In some embodiments the patient is a mammal such as a non-human primate or human patient.


The term “endodomain” as used herein refers to the region found in some membrane proteins, such as transmembrane proteins, that extends into the interior space defined by the cell surface membrane. In mammalian cells, the endodomain is the cytoplasmic region of the membrane protein. In cells, the endodomain interacts with intracellular constituents and can be play a role in signal transduction and thus, in some cases, can be an intracellular signaling domain. The endodomain of a cellular transmembrane protein is alternately referred to as a cytoplasmic domain, which, in some cases, can be a cytoplasmic signaling domain.


The terms “enhanced” or “increased” as used herein in the context of increasing immunological activity of a mammalian lymphocyte means to increase one or more activities the lymphocyte. An increased activity can be one or more of increase cell survival, cell proliferation, cytokine production, or T-cell cytotoxicity, such as by a statistically significant amount. In some embodiments, reference to increased immunological activity means to increase interferon gamma (IFN-gamma) production, such as by a statistically significant amount. In some embodiments, the immunological activity can be assessed in a mixed lymphocyte reaction (MLR) assay. Methods of conducting MLR assays are known in the art. Wang et al., Cancer Immunol Res. 2014 September: 2(9):846-56. Other methods of assessing activities of lymphocytes are known in the art, including any assay as described herein. In some embodiments an enhancement can be an increase of at least 10%, 20%, 30%, 40%, 50%, 75%, 100%, 200%, 300%, 400%, or 500% greater than a non-zero control value.


The term “engineered cell” as used herein refers to a mammalian cell that has been genetically modified by human intervention such as by recombinant DNA methods or viral transduction. In some embodiments, the cell is an immune cell, such as a lymphocyte (e.g. T cell, B cell, NK cell) or an antigen presenting cell (e.g. dendritic cell). The cell can be a primary cell from a patient or can be a cell line. In some embodiments, an engineered cell of the invention comprises a variant PD-L2 of the invention engineered to modulate immunological activity of a T-cell expressing PD-1 and/or RGMb to which the variant PD-L2 specifically binds. In some embodiments, the variant PD-L2 is a transmembrane immunomodulatory protein (hereinafter referred to as “TIP”) containing the extracellular domain or a portion thereof containing the IgV domain linked to a transmembrane domain (e.g. a PD-L2 transmembrane domain) and, optionally, an intracellular signaling domain. In some cases, the TIP is formatted as a chimeric receptor containing a heterologous cytoplasmic signaling domain or endodomain. In some embodiments, an engineered cell is capable of expressing and secreting an immunomodulatory protein as described herein. Among provided engineered cells also are cells further containing an engineered T-cell receptor (TCR) or chimeric antigen receptor (CAR).


The term “engineered T-cell” as used herein refers to a T-cell such as a T helper cell, cytotoxic T-cell (alternatively, cytotoxic T lymphocyte or CTL), natural killer T-cell, regulatory T-cell, memory T-cell, or gamma delta T-cell, that has been genetically modified by human intervention such as by recombinant DNA methods or viral transduction methods. An engineered T-cell comprises a variant PD-L2 transmembrane immunomodulatory protein (TIP) or secreted immunodulatory protein (SIP) of the present invention that is expressed on the T-cell and is engineered to modulate immunological activity of the engineered T-cell itself, or a mammalian cell to which the variant PD-L2 expressed on the T-cell specifically binds.


The term “engineered T-cell receptor” or “engineered TCR” refers to a T-cell receptor (TCR) engineered to specifically bind with a desired affinity to a major histocompatibility complex (MHC)/peptide target antigen that is selected, cloned, and/or subsequently introduced into a population of T-cells, often used for adoptive immunotherapy. In contrast to engineered TCRs, CARs are engineered to bind target antigens in a MHC independent manner.


The term “expressed on” as used herein is used in reference to a protein expressed on the surface of a cell, such as a mammalian cell. Thus, the protein is expressed as a membrane protein. In some embodiments, the expressed protein is a transmembrane protein. In some embodiments, the protein is conjugated to a small molecule moiety such as a drug or detectable label. Proteins expressed on the surface of a cell can include cell-surface proteins such as cell surface receptors that are expressed on mammalian cells.


The term “half-life extending moiety” refers to a moiety of a polypeptide fusion or chemical conjugate that extends the half-life of a protein circulating in mammalian blood serum compared to the half-life of the protein that is not so conjugated to the moiety. In some embodiments, half-life is extended by greater than or greater than about 1.2-fold, 1.5-fold, 2.0-fold, 3.0-fold, 4.0-fold, 5.0-fold, or 6.0-fold. In some embodiments, half-life is extended by more than 6 hours, more than 12 hours, more than 24 hours, more than 48 hours, more than 72 hours, more than 96 hours or more than 1 week after in vivo administration compared to the protein without the half-life extending moiety. The half-life refers to the amount of time it takes for the protein to lose half of its concentration, amount, or activity. Half-life can be determined for example, by using an ELISA assay or an activity assay. Exemplary half-life extending moieties include an Fc domain, a multimerization domain, polyethylene glycol (PEG), hydroxyethyl starch (HES), XTEN (extended recombinant peptides; see, WO2013130683), human serum albumin (HSA), bovine serum albumin (BSA), lipids (acylation), and poly-Pro-Ala-Ser (PAS), and polyglutamic acid (glutamylation).


The term “immunological synapse” or “immune synapse” as used herein means the interface between a mammalian cell that expresses MHC I (major histocompatibility complex) or MHC II, such as an antigen-presenting cell or tumor cell, and a mammalian lymphocyte such as an effector T cell or Natural Killer (NK) cell.


An Fc (fragment crystallizable) region or domain of an immunoglobulin molecule (also termed an Fc polypeptide) corresponds largely to the constant region of the immunoglobulin heavy chain, and is responsible for various functions, including the antibody's effector function(s). The Fc domain contains part or all of a hinge domain of an immunoglobulin molecule plus a CH2 and a CH3 domain. The Fc domain can form a dimer of two polypeptide chains joined by one or more disulfide bonds. In some embodiments, the Fc is a variant Fc that exhibits reduced (e.g. reduced greater than 30%, 40%, 50%, 60%, 70%, 80%, 90% or more) activity to facilitate an effector function. In some embodiments, reference to amino acid substitutions in an Fc region is by EU numbering system unless described with reference to a specific SEQ ID NO. EU numbering is known and is according to the most recently updated IMGT Scientific Chart (IMGT®, the international ImMunoGeneTics information system®, www.imgt.org/IMGTScientificChart/Numbering/Hu_IGHGnber.html (created: 17 May 2001, last updated: 10 Jan. 2013) and the EU index as reported in Kabat, E. A. et al. Sequences of Proteins of Immunological interest. 5th ed. US Department of Health and Human Services, NIH publication No. 91-3242 (1991).


An immunoglobulin Fc fusion (“Fc-fusion”), such as an immunomodulatory Fc fusion protein, is a molecule comprising one or more polypeptides (or one or more small molecules) operably linked to an Fc region of an immunoglobulin. An Fc-fusion may comprise, for example, the Fc region of an antibody (which facilitates effector functions and pharmacokinetics) and a variant PD-L2. An immunoglobulin Fc region may be linked indirectly or directly to one or more variant PD-L2 or small molecules (fusion partners). Various linkers are known in the art and can optionally be used to link an Fc to a fusion partner to generate an Fc-fusion. Fc-fusions of identical species can be dimerized to form Fc-fusion homodimers, or using non-identical species to form Fc-fusion heterodimers. In some embodiments, the Fc is a mammalian Fc such as a murine or human Fc.


The term “host cell” refers to a cell that can be used to express a protein encoded by a recombinant expression vector. A host cell can be a prokaryote, for example, E. coli, or it can be a eukaryote, for example, a single-celled eukaryote (e.g., a yeast or other fungus), a plant cell (e.g., a tobacco or tomato plant cell), an animal cell (e.g., a human cell, a monkey cell, a hamster cell, a rat cell, a mouse cell, or an insect cell) or a hybridoma. Examples of host cells include Chinese hamster ovary (CHO) cells or their derivatives such as Veggie CHO and related cell lines which grow in serum-free media or CHO strain DX-B11, which is deficient in DHFR. Another example is Human Endothelial Kidney 293 cells or their derivatives. In some embodiments, a host cell is a mammalian cell (e.g., a human cell, a monkey cell, a hamster cell, a rat cell, a mouse cell, or an insect cell).


The term “immunoglobulin” (abbreviated “Ig”) as used herein refers to a mammalian immunoglobulin protein including any of the five human classes of antibody: IgA (which includes subclasses IgA1 and IgA2), IgD, IgE, IgG (which includes subclasses IgG1, IgG2, IgG3, and IgG4), and IgM. The term is also inclusive of immunoglobulins that are less than full-length, whether wholly or partially synthetic (e.g., recombinant or chemical synthesis) or naturally produced, such as antigen binding fragment (Fab), variable fragment (Fv) containing VH and VL, the single chain variable fragment (scFv) containing VH and VL linked together in one chain, as well as other antibody V region fragments, such as Fab′, F(ab)2, F(ab′)2, dsFv diabody, Fc, and Fd polypeptide fragments. Bispecific antibodies, homobispecific and heterobispecific, are included within the meaning of the term.


The term “immunoglobulin superfamily” or “IgSF” as used herein means the group of cell surface and soluble proteins that are involved in the recognition, binding, or adhesion processes of cells. Molecules are categorized as members of this superfamily based on shared structural features with immunoglobulins (i.e., antibodies); they all possess a domain known as an immunoglobulin domain or fold. Members of the IgSF include cell surface antigen receptors, co-receptors and co-stimulatory molecules of the immune system, molecules involved in antigen presentation to lymphocytes, cell adhesion molecules, certain cytokine receptors and intracellular muscle proteins. They are commonly associated with roles in the immune system. Proteins in the immunological synapse are often members of the IgSF. IgSF can also be classified into “subfamilies” based on shared properties such as function. Such subfamilies typically consist of from 4 to 30 IgSF members.


The terms “IgSF domain” or “immunoglobulin domain” or “Ig domain” as used herein refers to a structural domain of IgSF proteins. Ig domains are named after the immunoglobulin molecules. They contain about 70-110 amino acids and are categorized according to their size and function. Ig-domains possess a characteristic Ig-fold, which has a sandwich-like structure formed by two sheets of antiparallel beta strands. Interactions between hydrophobic amino acids on the inner side of the sandwich and highly conserved disulfide bonds formed between cysteine residues in the B and F strands, stabilize the Ig-fold. One end of the Ig domain has a section called the complementarity determining region that is important for the specificity of antibodies for their ligands. The Ig like domains can be classified (into classes) as: IgV, IgC (which either can be an IgC1 or IgC2), or IgI. Most Ig domains are either variable (IgV) or constant (IgC). IgV domains with 9 beta strands are generally longer than IgC domains with 7 beta strands. Ig domains of some members of the IgSF resemble IgV domains in the amino acid sequence, yet are similar in size to IgC domains. These are called IgC2 domains, while standard IgC domains are called IgC1 domains. T-cell receptor (TCR) chains contain two Ig domains in the extracellular portion; one IgV domain at the N-terminus and one IgC1 domain adjacent to the cell membrane. PD-L2 contains two Ig domains: one IgV and one IgC domain.


The term “IgSF species” as used herein means an ensemble of IgSF member proteins with identical or substantially identical primary amino acid sequence. Each mammalian immunoglobulin superfamily (IgSF) member defines a unique identity of all IgSF species that belong to that IgSF member. Thus, each IgSF family member is unique from other IgSF family members and, accordingly, each species of a particular IgSF family member is unique from the species of another IgSF family member. Nevertheless, variation between molecules that are of the same IgSF species may occur owing to differences in post-translational modification such as glycosylation, phosphorylation, ubiquitination, nitrosylation, methylation, acetylation, and lipidation. Additionally, minor sequence differences within a single IgSF species owing to gene polymorphisms constitute another form of variation within a single IgSF species as do wild type truncated forms of IgSF species owing to, for example, proteolytic cleavage. A “cell surface IgSF species” is an IgSF species expressed on the surface of a cell, generally a mammalian cell.


The term “immunological activity” as used herein in the context of mammalian lymphocytes such as T-cells refers to one or more cell survival, cell proliferation, cytokine production (e.g. interferon-gamma), or T-cell cytotoxicity activities. In some cases, an immunological activity can mean the cell expression of cytokines, such as chemokines or interleukins. Assays for determining enhancement or suppression of immunological activity include the MLR (mixed lymphocyte reaction) assays measuring interferon-gamma cytokine levels in culture supernatants (Wang et al., Cancer Immunol Res. 2014 September: 2(9):846-56), SEB (staphylococcal enterotoxin B) T cell stimulation assay (Wang et al., Cancer Immunol Res. 2014 September: 2(9):846-56), and anti-CD3 T cell stimulation assays (Li and Kurlander, J Transl Med. 2010: 8: 104). Since T cell activation is associated with secretion of IFN-gamma cytokine, detecting IFN-gamma levels in culture supernatants from these in vitro human T cell assays can be assayed using commercial ELISA kits (Wu et al, Immunol Lett 2008 Apr. 15; 117(1): 57-62). Induction of an immune response results in an increase in immunological activity relative to quiescent lymphocytes. An immunomodulatory protein, such as a variant PD-L2 polypeptide containing an affinity modified IgSF domain, as provided herein can in some embodiments increase or, in alternative embodiments, decrease IFN-gamma (interferon-gamma) expression in a primary T-cell assay relative to a wild-type IgSF member or IgSF domain control. Those of skill will recognize that the format of the primary T-cell assay used to determine an increase in IFN-gamma expression can differ from that employed to assay for a decrease in IFN-gamma expression. In assaying for the ability of an immunomodulatory protein or affinity modified IgSF domain of the invention to alter IFN-gamma expression in a primary T-cell assay, a Mixed Lymphocyte Reaction (MLR) assay can be used. Conveniently, in some cases, a soluble form of an affinity modified IgSF domain of the invention can be employed to determine its ability to increase or decrease the IFN-gamma expression in a MLR. Alternatively, a co-immobilization assay can be used. In a co-immobilization assay, a T-cell receptor signal, provided in some embodiments by anti-CD3 antibody, is used in conjunction with a co-immobilized affinity modified IgSF domain, such as variant PD-L2, to determine the ability to increase or decrease IFN-gamma expression relative to a wild-type IgSF domain control. Methods to assay the immunological activity of engineered cells, including to evaluate the activity of a variant PD-L2 transmembrane immunomodulatory protein, are known in the art and include, but are not limited to, the ability to expand T cells following antigen stimulation, sustain T cell expansion in the absence of re-stimulation, and anti-cancer activities in appropriate animal models. Assays also include assays to assess cytotoxicity, including a standard 51Cr-release assay (see e.g. Milone et al., (2009) Molecular Therapy 17: 1453-1464) or flow based cytotoxicity assays, or an impedance based cytotoxicity assay (Peper et al. (2014) Journal of Immunological Methods, 405:192-198).


An “immunomodulatory polypeptide” or “immunomodulatory protein” is a polypeptide or protein molecule that modulates immunological activity. By “modulation” or “modulating” an immune response is meant that immunological activity is either increased or decreased. An immunomodulatory protein can be a single polypeptide chain or a multimer (dimers or higher order multimers) of at least two polypeptide chains covalently bonded to each other by, for example, interchain disulfide bonds. Thus, monomeric, dimeric, and higher order multimeric polypeptides are within the scope of the defined term. Multimeric polypeptides can be homomultimeric (of identical polypeptide chains) or heteromultimeric (of non-identical polypeptide chains). An immunomodulatory protein of the invention comprises a variant PD-L2.


The term “increase” as used herein means to increase by a statistically significant amount. An increase can be at least 5%, 10%, 20%, 30%, 40%, 50%, 75%, 100%, or greater than a non-zero control value.


An “isoform” of PD-L2 is one of a plurality naturally occurring PD-L2 polypeptides that differ in amino acid sequence. Isoforms can be the product of splice variants of an RNA transcript expressed by a single gene, or the expression product of highly similar but different genes yielding a functionally similar protein such as may occur from gene duplication. As used herein, the term “isoform” of PD-L2 also refers to the product of different alleles of a PD-L2 gene.


The term “lymphocyte” as used herein means any of three subtypes of white blood cell in a mammalian immune system. They include natural killer cells (NK cells) (which function in cell-mediated, cytotoxic innate immunity), T cells (for cell-mediated, cytotoxic adaptive immunity), and B cells (for humoral, antibody-driven adaptive immunity). T cells include: T helper cells, cytotoxic T-cells, natural killer T-cells, memory T-cells, regulatory T-cells, or gamma delta T-cells. Innate lymphoid cells (ILC) are also included within the definition of lymphocyte.


The terms “mammal,” or “patient” specifically includes reference to at least one of a: human, chimpanzee, rhesus monkey, cynomolgus monkey, dog, cat, mouse, or rat.


The term “membrane protein” as used herein means a protein that, under physiological conditions, is attached directly or indirectly to a lipid bilayer. A lipid bilayer that forms a membrane can be a biological membrane such as a eukaryotic (e.g., mammalian) cell membrane or an artificial (i.e., man-made) membrane such as that found on a liposome. Attachment of a membrane protein to the lipid bilayer can be by way of covalent attachment, or by way of non-covalent interactions such as hydrophobic or electrostatic interactions. A membrane protein can be an integral membrane protein or a peripheral membrane protein. Membrane proteins that are peripheral membrane proteins are non-covalently attached to the lipid bilayer or non-covalently attached to an integral membrane protein. A peripheral membrane protein forms a temporary attachment to the lipid bilayer such that under the range of conditions that are physiological in a mammal, peripheral membrane protein can associate and/or disassociate from the lipid bilayer. In contrast to peripheral membrane proteins, integral membrane proteins form a substantially permanent attachment to the membrane's lipid bilayer such that under the range of conditions that are physiological in a mammal, integral membrane proteins do not disassociate from their attachment to the lipid bilayer. A membrane protein can form an attachment to the membrane by way of one layer of the lipid bilayer (monotopic), or attached by way of both layers of the membrane (polytopic). An integral membrane protein that interacts with only one lipid bilayer is an “integral monotopic protein”. An integral membrane protein that interacts with both lipid bilayers is an “integral polytopic protein” alternatively referred to herein as a “transmembrane protein”.


The terms “modulating” or “modulate” as used herein in the context of an immune response, such as a mammalian immune response, refer to any alteration, such as an increase or a decrease, of existing or potential immune responses that occurs as a result of administration of an immunomodulatory polypeptide comprising a variant PD-L2 of the present invention or as a result of administration of engineered cells expresses an immunomodulatory protein, such as a variant PD-L2 transmembrane immunomodulatory protein of the present invention. Thus, it refers to an alteration, such as an increase or decrease, of an immune response as compared to the immune response that occurs or is present in the absence of the administration of the immunomodulatory protein comprising the variant PD-L2 or cells expressing such an immunomodulatory polypeptide. Such modulation includes any induction, activation, suppression or alteration in degree or extent of immunological activity of an immune cell. Immune cells include B cells, T cells, NK (natural killer) cells, NK T cells, professional antigen-presenting cells (APCs), and non-professional antigen-presenting cells, and inflammatory cells (neutrophils, macrophages, monocytes, eosinophils, and basophils). Modulation includes any change imparted on an existing immune response, a developing immune response, a potential immune response, or the capacity to induce, regulate, influence, or respond to an immune response. Modulation includes any alteration in the expression and/or function of genes, proteins and/or other molecules in immune cells as part of an immune response. Modulation of an immune response or modulation of immunological activity includes, for example, the following: elimination, deletion, or sequestration of immune cells; induction or generation of immune cells that can modulate the functional capacity of other cells such as autoreactive lymphocytes, antigen presenting cells, or inflammatory cells; induction of an unresponsive state in immune cells (i.e., anergy); enhancing or suppressing the activity or function of immune cells, including but not limited to altering the pattern of proteins expressed by these cells. Examples include altered production and/or secretion of certain classes of molecules such as cytokines, chemokines, growth factors, transcription factors, kinases, costimulatory molecules, or other cell surface receptors or any combination of these modulatory events. Modulation can be assessed, for example, by an alteration in IFN-gamma (interferon gamma) expression relative to the wild-type PD-L2 control in a primary T cell assay (see, Zhao and Ji, Exp Cell Res. 2016 Jan. 1; 340(1) 132-138). Modulation can be assessed, for example, by an alteration of an immunological activity of engineered cells, such as an alteration in in cytotoxic activity of engineered cells or an alteration in cytokine secretion of engineered cells relative to cells engineered with a wild-type PD-L2 transmembrane protein


The term “molecular species” as used herein means an ensemble of proteins with identical or substantially identical primary amino acid sequence. Each mammalian immunoglobulin superfamily (IgSF) member defines a collection of identical or substantially identical molecular species. Thus, for example, human PD-L2 is an IgSF member and each human PD-L2 molecule is a molecular species of PD-L2. Variation between molecules that are of the same molecular species may occur owing to differences in post-translational modification such as glycosylation, phosphorylation, ubiquitination, nitrosylation, methylation, acetylation, and lipidation. Additionally, minor sequence differences within a single molecular species owing to gene polymorphisms constitute another form of variation within a single molecular species as do wild type truncated forms of a single molecular species owing to, for example, proteolytic cleavage. A “cell surface molecular species” is a molecular species expressed on the surface of a mammalian cell. Two or more different species of protein, each of which is present exclusively on one or exclusively the other (but not both) of the two mammalian cells forming the IS, are said to be in “cis” or “cis configuration” with each other. Two different species of protein, the first of which is exclusively present on one of the two mammalian cells forming the IS and the second of which is present exclusively on the second of the two mammalian cells forming the IS, are said to be in “trans” or “trans configuration.” Two different species of protein each of which is present on both of the two mammalian cells forming the IS are in both cis and trans configurations on these cells.


The term, a “multimerization domain” refers to a sequence of amino acids that promotes stable interaction of a polypeptide molecule with one or more additional polypeptide molecules, each containing a complementary multimerization domain (e.g. a first multimerization domain and a second multimerization domain), which can be the same or a different multimerization domain. The interactions between complementary multimerization domains, e.g. interaction between a first multimerization domain and a second multimerization domain, form a stable protein-protein interaction to produce a multimer of the polypeptide molecule with the additional polypeptide molecule. In some cases, the multimerization domain is the same and interacts with itself to form a stable protein-protein interaction between two polypeptide chains. Generally, a polypeptide is joined directly or indirectly to the multimerization domain. Exemplary multimerization domains include the immunoglobulin sequences or portions thereof, leucine zippers, hydrophobic regions, hydrophilic regions, and compatible protein-protein interaction domains. The multimerization domain, for example, can be an immunoglobulin constant region or domain, such as, for example, the Fc domain or portions thereof from IgG, including IgG1, IgG2, IgG3 or IgG4 subtypes, IgA, IgE, IgD and IgM and modified forms thereof.


The terms “nucleic acid” and “polynucleotide” are used interchangeably to refer to a polymer of nucleic acid residues (e.g., deoxyribonucleotides or ribonucleotides) in either single- or double-stranded form. Unless specifically limited, the terms encompass nucleic acids containing known analogues of natural nucleotides and that have similar binding properties to it and are metabolized in a manner similar to naturally-occurring nucleotides. Unless otherwise indicated, a particular nucleic acid sequence also implicitly encompasses conservatively modified variants thereof (e.g., degenerate codon substitutions) and complementary nucleotide sequences as well as the sequence explicitly indicated (a “reference sequence”). Specifically, degenerate codon substitutions may be achieved by generating sequences in which the third position of one or more selected (or all) codons is substituted with mixed-base and/or deoxyinosine residues. The term nucleic acid or polynucleotide encompasses cDNA or mRNA encoded by a gene.


The term “non-competitive binding” as used herein means the ability of a protein to specifically bind simultaneously to at least two cognate binding partners. Thus, the protein is able to bind to at least two different cognate binding partners at the same time, although the binding interaction need not be for the same duration such that, in some cases, the protein is specifically bound to only one of the cognate binding partners. In some embodiments, the binding occurs under specific binding conditions. In some embodiments, the simultaneous binding is such that binding of one cognate binding partner does not substantially inhibit simultaneous binding to a second cognate binding partner. In some embodiments, non-competitive binding means that binding a second cognate binding partner to its binding site on the protein does not displace the binding of a first cognate binding partner to its binding site on the protein. Methods of assessing non-competitive binding are well known in the art such as the method described in Perez de La Lastra et al., Immunology, 1999 April: 96(4): 663-670. In some cases, in non-competitive interactions, the first cognate binding partner specifically binds at an interaction site that does not overlap with the interaction site of the second cognate binding partner such that binding of the second cognate binding partner does not directly interfere with the binding of the first cognate binding partner. Thus, any effect on binding of the cognate binding partner by the binding of the second cognate binding partner is through a mechanism other than direct interference with the binding of the first cognate binding partner. For example, in the context of enzyme-substrate interactions, a non-competitive inhibitor binds to a site other than the active site of the enzyme. Non-competitive binding encompasses uncompetitive binding interactions in which a second cognate binding partner specifically binds at an interaction site that does not overlap with the binding of the first cognate binding partner but binds to the second interaction site only when the first interaction site is occupied by the first cognate binding partner.


The term “pharmaceutical composition” refers to a composition suitable for pharmaceutical use in a mammalian subject, often a human. A pharmaceutical composition typically comprises an effective amount of an active agent (e.g., an immunomodulatory polypeptide comprising a variant PD-L2 or engineered cells expressing a variant PD-L2 transmembrane immunomodulatory protein) and a carrier, excipient, or diluent. The carrier, excipient, or diluent is typically a pharmaceutically acceptable carrier, excipient or diluent, respectively.


The terms “polypeptide” and “protein” are used interchangeably herein and refer to a molecular chain of two or more amino acids linked through peptide bonds. The terms do not refer to a specific length of the product. Thus, “peptides,” and “oligopeptides,” are included within the definition of polypeptide. The terms include post-translational modifications of the polypeptide, for example, glycosylations, acetylations, phosphorylations and the like. The terms also include molecules in which one or more amino acid analogs or non-canonical or unnatural amino acids are included as can be synthesized, or expressed recombinantly using known protein engineering techniques. In addition, proteins can be derivatized.


The term “primary T-cell assay” as used herein refers to an in vitro assay to measure interferon-gamma (“IFN-gamma”) expression. A variety of such primary T-cell assays are known in the art. In a preferred embodiment, the assay used is an anti-CD3 coimmobilizaton assay. In this assay, primary T cells are stimulated by anti-CD3 immobilized with or without additional recombinant proteins. Culture supernatants are harvested at timepoints, usually 24-72 hours. In another embodiment, the assay used is the MLR. In this assay, primary T cells are stimulated with allogeneic APC. Culture supernatants are harvested at timepoints, usually 24-72 hours. Human IFN-gamma levels are measured in culture supernatants by standard ELISA techniques. Commercial kits are available from vendors and the assay is performed according to manufacturer's recommendation.


The term “purified” as applied to nucleic acids, such as encoding immunomodulatory proteins of the invention, generally denotes a nucleic acid or polypeptide that is substantially free from other components as determined by analytical techniques well known in the art (e.g., a purified polypeptide or polynucleotide forms a discrete band in an electrophoretic gel, chromatographic eluate, and/or a media subjected to density gradient centrifugation). For example, a nucleic acid or polypeptide that gives rise to essentially one band in an electrophoretic gel is “purified.” A purified nucleic acid or protein of the invention is at least about 50% pure, usually at least about 75%, 80%, 85%, 90%, 95%, 96%, 99% or more pure (e.g., percent by weight or on a molar basis).


The term “recombinant” indicates that the material (e.g., a nucleic acid or a polypeptide) has been artificially (i.e., non-naturally) altered by human intervention. The alteration can be performed on the material within, or removed from, its natural environment or state. For example, a “recombinant nucleic acid” is one that is made by recombining nucleic acids, e.g., during cloning, affinity modification, DNA shuffling or other well-known molecular biological procedures. A “recombinant DNA molecule,” is comprised of segments of DNA joined together by means of such molecular biological techniques. The term “recombinant protein” or “recombinant polypeptide” as used herein refers to a protein molecule which is expressed using a recombinant DNA molecule. A “recombinant host cell” is a cell that contains and/or expresses a recombinant nucleic acid or that is otherwise altered by genetic engineering, such as by introducing into the cell a nucleic acid molecule encoding a recombinant protein, such as a transmembrane immunomodulatory protein provided herein. Transcriptional control signals in eukaryotes comprise “promoter” and “enhancer” elements. Promoters and enhancers consist of short arrays of DNA sequences that interact specifically with cellular proteins involved in transcription. Promoter and enhancer elements have been isolated from a variety of eukaryotic sources including genes in yeast, insect and mammalian cells and viruses (analogous control elements, i.e., promoters, are also found in prokaryotes). The selection of a particular promoter and enhancer depends on what cell type is to be used to express the protein of interest. The terms “in operable combination,” “in operable order” and “operably linked” as used herein refer to the linkage of nucleic acid sequences in such a manner or orientation that a nucleic acid molecule capable of directing the transcription of a given gene and/or the synthesis of a desired protein molecule is produced.


The term “recombinant expression vector” as used herein refers to a DNA molecule containing a desired coding sequence and appropriate nucleic acid sequences necessary for the expression of the operably linked coding sequence in a particular host cell. Nucleic acid sequences necessary for expression in prokaryotes include a promoter, optionally an operator sequence, a ribosome binding site and possibly other sequences. Eukaryotic cells are known to utilize promoters, enhancers, and termination and polyadenylation signals. A secretory signal peptide sequence can also, optionally, be encoded by the recombinant expression vector, operably linked to the coding sequence for the recombinant protein, such as a recombinant fusion protein, so that the expressed fusion protein can be secreted by the recombinant host cell, for easier isolation of the fusion protein from the cell, if desired. The term includes the vector as a self-replicating nucleic acid structure as well as the vector incorporated into the genome of a host cell into which it has been introduced. Among the vectors are viral vectors, such as lentiviral vectors.


The term “selectivity” refers to the preference of a subject protein, or polypeptide, for specific binding of one substrate, such as one cognate binding partner, compared to specific binding for another substrate, such as a different cognate binding partner of the subject protein. Selectivity can be reflected as a ratio of the binding activity (e.g. binding affinity) of a subject protein and a first substrate, such as a first cognate binding partner, (e.g., Kd1) and the binding activity (e.g. binding affinity) of the same subject protein with a second cognate binding partner (e.g., Kd2).


The term “sequence identity” as used herein refers to the sequence identity between genes or proteins at the nucleotide or amino acid level, respectively. “Sequence identity” is a measure of identity between proteins at the amino acid level and a measure of identity between nucleic acids at nucleotide level. The protein sequence identity may be determined by comparing the amino acid sequence in a given position in each sequence when the sequences are aligned. Similarly, the nucleic acid sequence identity may be determined by comparing the nucleotide sequence in a given position in each sequence when the sequences are aligned. Methods for the alignment of sequences for comparison are well known in the art, such methods include GAP, BESTFIT, BLAST, FASTA and TFASTA. The BLAST algorithm calculates percent sequence identity and performs a statistical analysis of the similarity between the two sequences. The software for performing BLAST analysis is publicly available through the National Center for Biotechnology information (NCBI) website.


The term “soluble” as used herein in reference to proteins, means that the protein is not a membrane protein. In general, a soluble protein contains only the extracellular domain of an IgSF family member receptor, or a portion thereof containing an IgSF domain or domains or specific-binding fragments thereof, but does not contain the transmembrane domain. In some cases, solubility of a protein can be improved by linkage or attachment, directly or indirectly via a linker, to an Fc domain, which, in some cases, also can improve the stability and/or half-life of the protein. In some aspects, a soluble protein is an Fc fusion protein.


The term “species” as used herein with respect to polypeptides or nucleic acids means an ensemble of molecules with identical or substantially identical sequences. Variation between polypeptides that are of the same species may occur owing to differences in post-translational modification such as glycosylation, phosphorylation, ubiquitination, nitrosylation, methylation, acetylation, and lipidation. Slightly truncated sequences of polypeptides that differ (or encode a difference) from the full length species at the amino-terminus or carboxy-terminus by no more than 1, 2, or 3 amino acid residues are considered to be of a single species. Such microheterogeneities are a common feature of manufactured proteins.


The term “specific binding fragment” as used herein in reference to a full-length wild-type mammalian PD-L2 polypeptide or an IgV or an IgC (e.g. IgC2) domain thereof, means a polypeptide having a subsequence of the full-length polypeptide or an IgV and/or IgC domain and that specifically binds in vitro and/or in vivo to a mammalian PD-1 and/or mammalian RGMb such as a human or murine PD-1 or RGMb. In some embodiments, the specific binding fragment comprises an PD-L2 IgV or a PD-L2 IgC2 subsequence that is at least 60%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% the sequence length of the full-length wild-type sequence or an IgV or a an IgC (e.g. IgC2) sequence thereof. The specific binding fragment can be altered in sequence to form a variant PD-L2 of the invention.


The term “specifically binds” as used herein means the ability of a protein, under specific binding conditions, to bind to a target protein such that its affinity or avidity is at least 5 times as great, but optionally at least 10, 20, 30, 40, 50, 100, 250 or 500 times as great, or even at least 1000 times as great as the average affinity or avidity of the same protein to a collection of random peptides or polypeptides of sufficient statistical size. A specifically binding protein need not bind exclusively to a single target molecule but may specifically bind to a non-target molecule due to similarity in structural conformation between the target and non-target (e.g., paralogs or orthologs). Those of skill will recognize that specific binding to a molecule having the same function in a different species of animal (i.e., ortholog) or to a non-target molecule having a substantially similar epitope as the target molecule (e.g., paralog) is possible and does not detract from the specificity of binding which is determined relative to a statistically valid collection of unique non-targets (e.g., random polypeptides). Thus, a polypeptide of the invention may specifically bind to more than one distinct species of target molecule due to cross-reactivity. Solid-phase ELISA immunoassays, ForteBio Octet, or Biacore measurements can be used to determine specific binding between two proteins. Generally, interactions between two binding proteins have dissociation constants (Kd) less than 1×10−5 M, and often as low as 1×10−12 M. In certain embodiments of the present disclosure, interactions between two binding proteins have dissociation constants of less than or less than about 1×10−6 M, 1×10−7 M, 1×10−8 M, 1×10−9 M, 1×10−10 M or 1×10−11M or less.


The terms “surface expresses” or “surface expression” in reference to a mammalian cell expressing a polypeptide means that the polypeptide is expressed as a membrane protein. In some embodiments, the membrane protein is a transmembrane protein.


As used herein, “synthetic,” with reference to, for example, a synthetic nucleic acid molecule or a synthetic gene or a synthetic peptide refers to a nucleic acid molecule or polypeptide molecule that is produced by recombinant methods and/or by chemical synthesis methods.


The term “targeting moiety” as used herein refers to a composition that is covalently or non-covalently attached to, or physically encapsulates, a polypeptide comprising a variant PD-L2 of the present invention. The targeting moiety has specific binding affinity for a desired counter-structure such as a cell surface receptor (e.g., PD-1), or a tumor antigen such as tumor specific antigen (TSA) or a tumor associated antigen (TAA) such as B7-H6. Typically, the desired counter-structure is localized on a specific tissue or cell-type. Targeting moieties include: antibodies, antigen binding fragment (Fab), variable fragment (Fv) containing VH and VL, the single chain variable fragment (scFv) containing VH and VL linked together in one chain, as well as other antibody V region fragments, such as Fab′, F(ab)2, F(ab′)2, dsFv diabody, nanobodies, soluble receptors, receptor ligands, affinity matured receptors or ligands, as well as small molecule (<500 dalton) compositions (e.g., specific binding receptor compositions). Targeting moieties can also be attached covalently or non-covalently to the lipid membrane of liposomes that encapsulate a polypeptide of the present invention.


The term “transmembrane protein” as used herein means a membrane protein that substantially or completely spans a lipid bilayer such as those lipid bilayers found in a biological membrane such as a mammalian cell, or in an artificial construct such as a liposome. The transmembrane protein comprises a transmembrane domain (“transmembrane domain”) by which it is integrated into the lipid bilayer and by which the integration is thermodynamically stable under physiological conditions. Transmembrane domains are generally predictable from their amino acid sequence via any number of commercially available bioinformatics software applications on the basis of their elevated hydrophobicity relative to regions of the protein that interact with aqueous environments (e.g., cytosol, extracellular fluid). A transmembrane domain is often a hydrophobic alpha helix that spans the membrane. A transmembrane protein can pass through the both layers of the lipid bilayer once or multiple times. A transmembrane protein includes the provided transmembrane immunomodulatory proteins described herein. In addition to the transmembrane domain, a transmembrane immunomodulatory protein of the invention further comprises an ectodomain and, in some embodiments, an endodomain.


The terms “treating,” “treatment,” or “therapy” of a disease or disorder as used herein mean slowing, stopping or reversing the disease or disorders progression, as evidenced by decreasing, cessation or elimination of either clinical or diagnostic symptoms, by administration of a therapeutic composition (e.g. containing an immunomodulatory protein or engineered cells) of the invention either alone or in combination with another compound as described herein. “Treating,” “treatment,” or “therapy” also means a decrease in the severity of symptoms in an acute or chronic disease or disorder or a decrease in the relapse rate as for example in the case of a relapsing or remitting autoimmune disease course or a decrease in inflammation in the case of an inflammatory aspect of an autoimmune disease. As used herein in the context of cancer, the terms “treatment” or, “inhibit,” “inhibiting” or “inhibition” of cancer refers to at least one of: a statistically significant decrease in the rate of tumor growth, a cessation of tumor growth, or a reduction in the size, mass, metabolic activity, or volume of the tumor, as measured by standard criteria such as, but not limited to, the Response Evaluation Criteria for Solid Tumors (RECIST), or a statistically significant increase in progression free survival (PFS) or overall survival (OS). “Preventing,” “prophylaxis,” or “prevention” of a disease or disorder as used in the context of this invention refers to the administration of an immunomodulatory polypeptide or engineered cells of the invention, either alone or in combination with another compound, to prevent the occurrence or onset of a disease or disorder or some or all of the symptoms of a disease or disorder or to lessen the likelihood of the onset of a disease or disorder.


The term “tumor specific antigen” or “TSA” as used herein refers to a counter-structure that is present primarily on tumor cells of a mammalian subject but generally not found on normal cells of the mammalian subject. A tumor specific antigen need not be exclusive to tumor cells but the percentage of cells of a particular mammal that have the tumor specific antigen is sufficiently high or the levels of the tumor specific antigen on the surface of the tumor are sufficiently high such that it can be targeted by anti-tumor therapeutics, such as immunomodulatory polypeptides of the invention, and provide prevention or treatment of the mammal from the effects of the tumor. In some embodiments, in a random statistical sample of cells from a mammal with a tumor, at least 50% of the cells displaying a TSA are cancerous. In other embodiments, at least 60%, 70%, 80%, 85%, 90%, 95%, or 99% of the cells displaying a TSA are cancerous.


The term “variant” (also “modified” or mutant”) as used in reference to a variant PD-L2 means a PD-L2, such as a mammalian (e.g., human or murine) PD-L2 created by human intervention. The variant PD-L2 is a polypeptide having an altered amino acid sequence, relative to an unmodified or wild-type PD-L2. The variant PD-L2 is a polypeptide which differs from a wild-type PD-L2 isoform sequence by one or more amino acid substitutions, deletions, additions, or combinations thereof. For purposes herein, the variant PD-L2 contains at least one affinity modified domain, whereby one or more of the amino acid differences occurs in an IgSF domain (e.g. IgV domain). A variant PD-L2 can contain 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 or more amino acid differences, such as amino acid substitutions. A variant PD-L2 polypeptide generally exhibits at least 50%, 60%, 70%, 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to a corresponding wild-type or unmodified PD-L2, such as to the sequence of SEQ ID NO:3, a mature sequence thereof (lacking the signal sequence) or a portion thereof containing the extracellular domain or an IgSF domain thereof. In some embodiments, a variant PD-L2 polypeptide exhibits at least 50%, 60%, 70%, 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to a corresponding wild-type or unmodified PD-L2 comprising the sequence set forth in SEQ ID NO:31 or SEQ ID NO: 55. Non-naturally occurring amino acids as well as naturally occurring amino acids are included within the scope of permissible substitutions or additions. A variant PD-L2 is not limited to any particular method of making and includes, for example, de novo chemical synthesis, de novo recombinant DNA techniques, or combinations thereof. A variant PD-L2 of the invention specifically binds to at least one or more of PD-1 or RGMb of a mammalian species. In some embodiments, the altered amino acid sequence results in an altered (i.e., increased or decreased) binding affinity or avidity to PD-1 and/or RGMb compared to the wild-type or unmodified PD-L2 protein. An increase or decrease in binding affinity or avidity can be determined using well known binding assays such as flow cytometry. Larsen et al., American Journal of Transplantation, Vol 5: 443-453 (2005). See also, Linsley et al., Immunity, Vol 1(9): 793-801 (1994). An increase in variant PD-L2 binding affinity or avidity to PD-1 and/or RGMb is to a value at least 5% greater than that of the wild-type or unmodified PD-L2 and in some embodiments, at least 10%, 15%, 20%, 30%, 40%, 50%, 100% greater than that of the wild-type or unmodified PD-L2 control value. A decrease in PD-L2 binding affinity or avidity to PD-1 and/or RGMb is to a value no greater than 95% of the wild-type or unmodified control values, and in some embodiments no greater than 80%, 70% 60%, 50%, 40%, 30%, 20%, 10%, 5%, or no detectable binding affinity or avidity of the wild-type or unmodified control values. A variant PD-L2 is altered in primary amino acid sequence by substitution, addition, or deletion of amino acid residues. The term “variant” in the context of variant PD-L2 is not to be construed as imposing any condition for any particular starting composition or method by which the variant PD-L2 is created. A variant PD-L2 can, for example, be generated starting from wild type mammalian PD-L2 sequence information, then modeled in silico for binding to PD-1 and/or RGMb, and finally recombinantly or chemically synthesized to yield a variant PD-L2 of the present invention. In but one alternative example, a variant PD-L2 can be created by site-directed mutagenesis of a wild-type PD-L2. Thus, variant PD-L2 denotes a composition and not necessarily a product produced by any given process. A variety of techniques including recombinant methods, chemical synthesis, or combinations thereof, may be employed.


The term “wild-type” or “natural” or “native” as used herein is used in connection with biological materials such as nucleic acid molecules, proteins (e.g., PD-L2), IgSF members, host cells, and the like, refers to those which are found in nature and not modified by human intervention.


II. VARIANT PD-L2 POLYPEPTIDES

Provided herein are variant PD-L2 polypeptides that exhibit altered (increased or decreased) binding activity or affinity for one or more of a PD-L2 cognate binding partner. In some embodiments, the PD-L2 cognate binding partner is PD-1 or RGMb. In some embodiments, the PD-L2 cognate binding partner is PD-1. In some embodiments, the variant PD-L2 polypeptide contains one or more amino acids modifications, such as one or more substitutions (alternatively, “mutations” or “replacements”), deletions or addition, in an immunoglobulin superfamily (IgSF) domain (IgD) relative to a wild-type or unmodified PD-L2 polypeptide or a portion of a wild-type or unmodified PD-L2 containing an immunoglobulin superfamily (IgSF) domain or a specific binding fragment thereof. Thus, a provided variant PD-L1 polypeptide is or comprises a variant IgD (hereinafter called “vIgD”) in which the one or more amino acid modifications (e.g. substitutions) is in an IgD.


In some embodiments, the IgD comprises an IgV domain or an IgC (e.g. IgC2) domain or specific binding fragment of the IgV domain or the IgC (e.g. IgC2) domain, or combinations thereof. In some embodiments, the IgD can be an IgV only, the combination of the IgV and IgC, including the entire extracellular domain (ECD), or any combination of Ig domains of PD-L2. Table 2 provides exemplary residues that correspond to IgV or IgC regions of PD-L2. In some embodiments, the variant PD-L2 polypeptide contains an IgV domain or an IgC domain or specific binding fragments thereof in which the at least one of the amino acid modifications (e.g. substitutions) is in the IgV domain or IgC domain or a specific binding fragment thereof. In some embodiments, the variant PD-L2 polypeptide contains an IgV domain or specific binding fragments thereof in which the at least one of the amino acid modifications (e.g. substitutions) is in the IgV domain or a specific binding fragment thereof. In some embodiments, by virtue of the altered binding activity or affinity, the altered IgV domain or IgC (e.g. IgC2) domain is an affinity-modified IgSF domain.


In some embodiments, the variant is modified in one more IgSF domains relative to the sequence of an unmodified PD-L2 sequence. In some embodiments, the unmodified PD-L2 sequence is a wild-type PD-L2. In some embodiments, the unmodified or wild-type PD-L2 has the sequence of a native PD-L2 or an ortholog thereof. In some embodiments, the unmodified PD-L2 is or comprises the extracellular domain (ECD) of PD-L2 or a portion thereof containing one or more IgSF domain (see Table 2). In some embodiments, the extracellular domain of an unmodified or wild-type PD-L2 polypeptide comprises an IgV domain and an IgC (e.g. IgC2) domain or domains. However, the variant PD-L2 polypeptide need not comprise both the IgV domain and the IgC (e.g. IgC2) domain or domains. In some embodiments, the variant PD-L2 polypeptide comprises or consists essentially of the IgV domain or a specific binding fragment thereof. In some embodiments, the variant PD-L2 polypeptide comprises or consists essentially of one or both of the IgC (e.g. IgC2) domain or specific binding fragments thereof. In some embodiments, the variant PD-L2 polypeptide comprises or consists essentially of only one of the IgC (e.g. IgC2) domain or a specific binding fragment thereof. In some embodiments, the variant PD-L2 polypeptide comprises the IgV domain or a specific binding fragment thereof, and the first and second IgC (e.g. IgC2) domains or specific binding fragment thereof. In some embodiments, the variant PD-L2 is soluble and lacks a transmembrane domain. In some embodiments, the variant PD-L2 further comprises a transmembrane domain and, in some cases, also a cytoplasmic domain.


In some embodiments, the wild-type or unmodified PD-L2 sequence is a mammalian PD-L2 sequence. In some embodiments, the wild-type or unmodified PD-L2 sequence can be a mammalian PD-L2 that includes, but is not limited to, human, mouse, cynomolgus monkey, or rat. In some embodiments, the wild-type or unmodified PD-L2 sequence is human.


In some embodiments, the wild-type or unmodified PD-L2 sequence has (i) the sequence of amino acids set forth in SEQ ID NO:3 or a mature form thereof lacking the signal sequence, (ii) a sequence of amino acids that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to SEQ ID NO:3 or the mature form thereof, or (iii) is a portion of (i) or (ii) containing an IgV domain or IgC (e.g. IgC2) domain or specific binding fragments thereof.


In some embodiments, the wild-type or unmodified PD-L2 sequence is or comprises an extracellular domain of the PD-L2 or a portion thereof. In some embodiments, the unmodified or wild-type PD-L2 polypeptide comprises the amino acid sequence set forth in SEQ ID NO: 31, or an ortholog thereof. In some cases, the unmodified or wild-type PD-L2 polypeptide can comprise (i) the sequence of amino acids set forth in SEQ ID NO: 31, (ii) a sequence of amino acids that has at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% sequence identity to SEQ ID NO: 31, or (iii) is a specific binding fragment of the sequence of (i) or (ii) comprising an IgV domain or an IgC (e.g. IgC2) domain.


In some embodiments, the wild-type or unmodified PD-L2 polypeptide comprises an IgV domain or an IgC (e.g. IgC2) domain or domains, or a specific binding fragment thereof. In some embodiments, the IgV domain of the wild-type or unmodified PD-L2 polypeptide comprises the amino acid sequence set forth in SEQ ID NO: 55 (corresponding to amino acid residues 21-118 of SEQ ID NO: 4), or an ortholog thereof. For example, the IgV domain of the unmodified or wild-type PD-L2 polypeptide can contain (i) the sequence of amino acids set forth in SEQ ID NO: 55, (ii) a sequence of amino acids that has at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% sequence identity to SEQ ID NO: 55, or (iii) a specific binding fragment of the sequence of (i) or (ii). In some embodiments, the wild-type or unmodified IgV domain is capable of binding one or more PD-L2 cognate binding proteins, such as one or more of PD-1 or RGMb.


In some embodiments, a first IgC2 domain of the wild-type or unmodified PD-L2 polypeptide comprises the amino acid sequence set forth as residues 122-203 of SEQ ID NO: 4, or an ortholog thereof. For example, an IgC2 domain of the unmodified or wild-type PD-L2 polypeptide can contain (i) the sequence of amino acids set forth residues 122-203 of SEQ ID NO: 4, (ii) a sequence of amino acids that has at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% sequence identity to residues 122-203 of SEQ ID NO: 4, or (iii) a specific binding fragment of (i) or (ii). In some embodiments, the wild-type or unmodified IgC domain is capable of binding one or more PD-L2 cognate binding proteins.


In some embodiments, the wild-type or unmodified PD-L2 polypeptide contains a specific binding fragment of PD-L2, such as a specific binding fragment of the IgV domain or the IgC (e.g. IgC2) domain. In some embodiments the specific binding fragment can bind PD-1 and/or RGMb. The specific binding fragment can have an amino acid length of at least 50 amino acids, such as at least 60, 70, 80, 90, 100, or 110 amino acids. In some embodiments, a specific binding fragment of the IgV domain contains an amino acid sequence that is at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% of the length of the IgV domain set forth as amino acids 21-118 of SEQ ID NO: 4. In some embodiments, a specific binding fragment of an IgC (e.g. IgC2) domain comprises an amino acid sequence that is at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% of the length of the IgC domain set forth as amino acids 122-203 of SEQ ID NO: 3.


In some embodiments, the variant PD-L2 polypeptide comprises the ECD domain or a portion thereof comprising one or more affinity modified IgSF domains. In some embodiments, the variant PD-L2 polypeptides can comprise an IgV domain or an IgC (e.g. IgC2) domain or domains, or a specific binding fragment of the IgV domain or a specific binding fragment of the IgC (e.g. IgC2) domain or domains in which one or more of the IgSF domains (IgV or IgC) contains the one or more amino acid modifications (e.g. substitutions). In some embodiments, the variant PD-L2 polypeptides can comprise an IgV domain and an IgC (e.g. IgC2) domain or domains, or a specific binding fragment of the IgV domain and a specific binding fragment of the IgC (e.g. IgC2) domain or domains, in which at least one of the IgV or IgC domain contains the amino acid modifications (e.g. substitutions). In some embodiments, the variant PD-L2 polypeptide comprises a full-length IgV domain. In some embodiments, the variant PD-L2 polypeptide comprises a full-length IgC (e.g. IgC2) domain or domains. In some embodiments, the variant PD-L2 polypeptide comprises a specific binding fragment of the IgV domain. In some embodiments, the variant PD-L2 polypeptide comprises a specific binding fragment of the IgC (e.g. IgC2) domain or domains. In some embodiments, the variant PD-L2 polypeptide comprises a full-length IgV domain and a full-length IgC (e.g. IgC2) domain or domains. In some embodiments, the variant PD-L2 polypeptide comprises a full-length IgV domain and a specific binding fragment of an IgC (e.g. IgC2) domain or domains. In some embodiments, the variant PD-L2 polypeptide comprises a specific binding fragment of an IgV domain and a full-length IgC (e.g. IgC2) domain or domains. In some embodiments, the variant PD-L2 polypeptide comprises a specific binding fragment of an IgV domain and a specific binding fragment of an IgC (e.g. IgC2) domain or domains.


In any of such embodiments, the one or more amino acid modifications (e.g. substitutions) of the variant PD-L2 polypeptides can be located in any one or more of the PD-L2 polypeptide IgSF domains. For example, in some embodiments, one or more amino acid modifications (e.g. substitutions) are located in the extracellular domain of the variant PD-L2 polypeptide. In some embodiments, one or more amino acid modifications (e.g. substitutions) are located in the IgV domain or specific binding fragment of the IgV domain. In some embodiments, one or more amino acid modifications (e.g. substitutions) are located in an IgC (e.g. IgC2) domain or specific binding fragment of an IgC (e.g. IgC2) domain.


Generally, each of the various attributes of polypeptides are separately disclosed below (e.g., soluble and membrane bound polypeptides, affinity of PD-L2 for PD-1 and RGMb, number of variations per polypeptide chain, number of linked polypeptide chains, the number and nature of amino acid alterations per variant PD-L2, etc.). However, as will be clear to the skilled artisan, any particular polypeptide can comprise a combination of these independent attributes. It is understood that reference to amino acids, including to a specific sequence set forth as a SEQ ID NO used to describe domain organization of an IgSF domain are for illustrative purposes and are not meant to limit the scope of the embodiments provided. It is understood that polypeptides and the description of domains thereof are theoretically derived based on homology analysis and alignments with similar molecules. Thus, the exact locus can vary, and is not necessarily the same for each protein. Hence, the specific IgSF domain, such as specific IgV domain or IgC domain, can be several amino acids (such as one, two, three or four) longer or shorter.


Further, various embodiments of the invention as discussed below are frequently provided within the meaning of a defined term as disclosed above. The embodiments described in a particular definition are therefore to be interpreted as being incorporated by reference when the defined term is utilized in discussing the various aspects and attributes described herein. Thus, the headings, the order of presentation of the various aspects and embodiments, and the separate disclosure of each independent attribute is not meant to be a limitation to the scope of the present disclosure.


Exemplary Modifications


Provided herein are variant PD-L2 polypeptides containing at least one affinity-modified IgSF domain (e.g. IgV or IgC) or a specific binding fragment thereof relative to an IgSF domain contained in a wild-type or unmodified PD-L2 polypeptide such that the variant PD-L2 polypeptide exhibits altered (increased or decreased) binding activity or affinity for one or more ligands PD-1 or RGMb compared to a wild-type or unmodified PD-L2 polypeptide. In some embodiments, a variant PD-L2 polypeptide has a binding affinity for PD-1 and/or RGMb that differs from that of a wild-type or unmodified PD-L2 polypeptide control sequence as determined by, for example, solid-phase ELISA immunoassays, flow cytometry, ForteBio Octet or Biacore assays. In some embodiments, the variant PD-L2 polypeptide has an increased binding affinity for PD-1 and/or RGMb. In some embodiments, the variant PD-L2 polypeptide has a decreased binding affinity for PD-1 and/or RGMb, relative to a wild-type or unmodified PD-L2 polypeptide. The PD-1 and/or the RGMb can be a mammalian protein, such as a human protein or a murine protein.


Binding affinities for each of the cognate binding partners are independent; that is, in some embodiments, a variant PD-L2 polypeptide has an increased binding affinity for one or both of PD-1 and/or RGMb, and a decreased binding affinity for one or both of PD-1 and RGMb, relative to a wild-type or unmodified PD-L2 polypeptide.


In some embodiments, the variant PD-L2 polypeptide has an increased binding affinity for PD-1, relative to a wild-type or unmodified PD-L2 polypeptide. In some embodiments, the variant PD-L2 polypeptide has an increased binding affinity for RGMb, relative to a wild-type or unmodified PD-L2 polypeptide. In some embodiments, the variant PD-L2 polypeptide has a decreased binding affinity for PD-1, relative to a wild-type or unmodified PD-L2 polypeptide. In some embodiments, the variant PD-L2 polypeptide has a decreased binding affinity for RGMb, relative to a wild-type or unmodified PD-L2polypeptide.


In some embodiments, the variant PD-L2 polypeptide has an increased binding affinity for PD-1 and RGMb, relative to a wild-type or unmodified PD-L2 polypeptide. In some embodiments, the variant PD-L2 polypeptide has an increased binding affinity for PD-1 and a decreased binding affinity for RGMb, relative to a wild-type or unmodified PD-L2 polypeptide. In some embodiments, the variant PD-L2 polypeptide has a decreased binding affinity for PD-1 and RGMb, relative to a wild-type or unmodified PD-L2 polypeptide. In some embodiments, the variant PD-L2 polypeptide has a decreased binding affinity for PD-1 and an increased binding affinity for RGMb, relative to a wild-type or unmodified PD-L2 polypeptide.


In some embodiments, a variant PD-L2 polypeptide with increased or greater binding affinity to PD-1 and/or RGMb will have an increase in binding affinity relative to the wild-type or unmodified PD-L2 polypeptide control of at least about 5%, such as at least about 10%, 15%, 20%, 25%, 35%, or 50% for the PD-1 and/or RGMb. In some embodiments, the increase in binding affinity relative to the wild-type or unmodified PD-L2 polypeptide is more than 1.2-fold, 1.5-fold, 2-fold, 3-fold, 4-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold, 20-fold, 30-fold 40-fold or 50-fold. In such examples, the wild-type or unmodified PD-L2 polypeptide has the same sequence as the variant PD-L2 polypeptide except that it does not contain the one or more amino acid modifications (e.g. substitutions).


In some embodiments, a variant PD-L2 polypeptide with reduced or decreased binding affinity to PD-1 and/or RGMb will have decrease in binding affinity relative to the wild-type or unmodified PD-L2 polypeptide control of at least 5%, such as at least about 10%, 15%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or more for the PD-1 and/or RGMb. In some embodiments, the decrease in binding affinity relative to the wild-type or unmodified PD-L2 polypeptide is more than 1.2-fold, 1.5-fold, 2-fold, 3-fold, 4-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold, 20-fold, 30-fold 40-fold or 50-fold. In such examples, the wild-type or unmodified PD-L2 polypeptide has the same sequence as the variant PD-L2 polypeptide except that it does not contain the one or more amino acid modifications (e.g. substitutions).


In some embodiments, the equilibrium dissociation constant (Kd) of any of the foregoing embodiments to PD-1 and/or RGMb can be less than 1×10−5 M, 1×10−6 M, 1×10−7 M, 1×10−8 M, 1×10−9 M, 1×10−10 M or 1×10−11M, or 1×10−12 M or less.


The wild-type or unmodified PD-L2 sequence does not necessarily have to be used as a starting composition to generate variant PD-L2 polypeptides described herein. Therefore, use of the term “modification”, such as “substitution” does not imply that the present embodiments are limited to a particular method of making variant PD-L2 polypeptides. Variant PD-L2 polypeptides can be made, for example, by de novo peptide synthesis and thus does not necessarily require a modification, such as a “substitution” in the sense of altering a codon to encode for the modification, e.g. substitution. This principle also extends to the terms “addition” and “deletion” of an amino acid residue which likewise do not imply a particular method of making. The means by which the variant PD-L2 polypeptides are designed or created is not limited to any particular method. In some embodiments, however, a wild-type or unmodified PD-L2 encoding nucleic acid is mutagenized from wild-type or unmodified PD-L2 genetic material and screened for desired specific binding affinity and/or induction of IFN-gamma expression or other functional activity. In some embodiments, a variant PD-L2 polypeptide is synthesized de novo utilizing protein or nucleic acid sequences available at any number of publicly available databases and then subsequently screened. The National Center for Biotechnology Information provides such information and its website is publicly accessible via the internet as is the UniProtKB database.


Unless stated otherwise, as indicated throughout the present disclosure, the amino acid modification(s) are designated by amino acid position number corresponding to the numbering of positions of the unmodified ECD sequence set forth in SEQ ID NO:31 or also, where applicable, the unmodified IgV sequence set forth in SEQ ID NO:55 or SEQ ID NO:115 (containing residues 1-102 of SEQ ID NO:31) as follows:









(SEQ ID NO: 31)


LFTVTVPKELYIIEHGSNVTLECNFDTGSHVNLGAITASLQKVENDTSPH





RERATLLEEQLPLGKASFHIPQVQVRDEGQYQCIIIYGVAWDYKYLTLKV





KASYRKINTHILKVPETDEVELTCQATGYPLAEVSWPNVSVPANTSHSRT





PEGLYQVTSVLRLKPPPGRNFSCVFWNTHVRELTLASIDLQSQMEPRTHP





T





(SEQ ID NO: 55)


FTVTVPKELYIIEHGSNVTLECNFDTGSHVNLGAITASLQKVENDTSPHR





ERATLLEEQLPLGKASFHIPQVQVRDEGQY QCIIIYGVAW DYKYLTLK





(SEQ ID NO: 115)


LFTVTVPKELYIIEHGSNVTLECNFDTGSHVNLGAITASLQKVENDTSPH





RERATLLEEQLPLGKASFHIPQVQVRDEGQY QCIIIYGVAW





DYKYLTLKVKA






It is within the level of a skilled artisan to identify the corresponding position of a modification, e.g. amino acid substitution, in a PD-L2 polypeptide, including portion thereof containing an IgSF domain (e.g. IgV) thereof, such as by alignment of a reference sequence with SEQ ID NO:31, SEQ ID NO:55 or SEQ ID NO:115. In the listing of modifications throughout this disclosure, the amino acid position is indicated in the middle, with the corresponding unmodified (e.g. wild-type) amino acid listed before the number and the identified variant amino acid substitution listed after the number. If the modification is a deletion of the position a “del” is indicated and if the modification is an insertion at the position an “ins” is indicated. In some cases, an insertion is listed with the amino acid position indicated in the middle, with the corresponding unmodified (e.g. wild-type) amino acid listed before and after the number and the identified variant amino acid insertion listed after the unmodified (e.g. wild-type) amino acid.


In some embodiments, the variant PD-L2 polypeptide has one or more amino acid modifications, e.g. substitutions in a wild-type or unmodified PD-L2 sequence. The one or more amino acid modifications, e.g. substitutions can be in the ectodomain (extracellular domain) of the wild-type or unmodified PD-L2 sequence. In some embodiments, the one or more amino acid modifications, e.g. substitutions are in the IgV domain or specific binding fragment thereof. In some embodiments, the one or more amino acid modifications, e.g. substitutions are in an IgC (e.g. IgC2) domain or specific binding fragment thereof. In some embodiments of the variant PD-L2 polypeptide, some of the one or more amino acid modifications, e.g. substitutions are in the IgV domain or a specific binding fragment thereof, and some of the one or more amino acid modifications, e.g. substitutions are in an IgC domain or domains (e.g. IgC2) or a specific binding fragment thereof.


In some embodiments, the variant PD-L2 polypeptide has up to 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 amino acid modifications, e.g. substitutions. The modifications, e.g. substitutions can be in the IgV domain or the IgC (e.g. IgC2) domain or domains. In some embodiments, the variant PD-L2 polypeptide has up to 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 amino acid modifications, e.g. substitutions in the IgV domain or specific binding fragment thereof. In some embodiments, the variant PD-L2 polypeptide has up to 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 amino acid modifications, e.g. substitutions in the IgC (e.g. IgC2) domain or domains or specific binding fragment thereof. In some embodiments, the variant PD-L2 polypeptide has at least about 85%, 86%, 86%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity with the wild-type or unmodified PD-L2 polypeptide or specific binding fragment thereof, such as with the amino acid sequence of SEQ ID NO: 31, 55 or 115.


In some embodiments, the variant PD-L2 polypeptide has one or more amino acid modifications, e.g. substitutions in an unmodified PD-L2 or specific binding fragment thereof corresponding to position(s) 2, 12, 13, 15, 18, 20, 23, 24, 28, 31, 32, 33, 36, 37, 39, 44, 45, 46, 47, 48, 58, 59, 65, 67, 69, 71, 72, 73, 74, 75, 76, 77, 82, 85, 86, 89, or 91 with reference to positions set forth in SEQ ID NO: 31. In some embodiments, such variant PD-L2 polypeptides exhibit altered binding affinity to one or more of PD-1 and/or RGMb compared to the wild-type or unmodified PD-L2 polypeptide. For example, in some embodiments, the variant PD-L2 polypeptide exhibits increased binding affinity to PD-1 and/or RGMb compared to a wild-type or unmodified PD-L2 polypeptide. In some embodiments, the variant PD-L2 polypeptide exhibits decreased binding affinity to PD-1 or RGMb compared to a wild-type or unmodified PD-L2 polypeptide.


In some embodiments, the variant PD-L2 polypeptide has one or more amino acid modifications, e.g. amino acid substitutions, selected from F2L, 112V, I13V, H15Q, N18D, T20A, N24S, C23S, G28V, N24D, V31A, V31M, N32D, L33P, L33H, L33F, I36V, T37A, S48C, S39I, E44D, E44V, N45S, D46E, T47A, E58G, E59G, K65R, S67L, H69L, P71S, Q72H, V73A, Q74R, V75G, R76G, D77N, Q82R, I85F, I86T, V89D, or W91R, or a conservative amino acid substitution thereof. A conservative amino acid substitution is any amino acid that falls in the same class of amino acids as the substituted amino acids, other than the wild-type or unmodified amino acid. The classes of amino acids are aliphatic (glycine, alanine, valine, leucine, and isoleucine), hydroxyl or sulfur-containing (serine, cysteine, threonine, and methionine), cyclic (proline), aromatic (phenylalanine, tyrosine, tryptophan), basic (histidine, lysine, and arginine), and acidic/amide (aspartate, glutamate, asparagine, and glutamine).


In some embodiments, the variant PD-L2 polypeptide has two or more amino acid modifications, e.g. amino acid substitutions, selected from F2L, I12V, I13V, H15Q, N18D, T20A, N24S, C23S, G28V, N24D, V31A, V31M, N32D, L33P, L33H, L33F, I36V, T37A, S48C, S39I, E44D, E44V, N45S, D46E, T47A, E58G, E59G, K65R, S67L, H69L, P71S, Q72H, V73A, Q74R, V75G, R76G, D77N, Q82R, I85F, I86T, V89D, or W91R.


In some embodiments, the amino acid modifications, e.g. amino acid substitutions, of a variant PD-L2 polypeptide include H15Q, N24D, E44D, V89D, Q82R/V89D, E59G/Q82R, S39I/V89D, S67L/V89D, S67L/I85F, S67L/I86T, H15Q/K65R, H15Q/Q72H/V89D, H15Q/S67L/R76G, H15Q/R76G/I85F, H15Q/T47A/Q82R, H15Q/Q82R/V89D, H15Q/C23S/I86T, H15Q/S39I/I86T, E44D/V89D/W91R, I13V/S67L/V89D, H15Q/S67L/I86T, I13V/H15Q/S67L/I86T, I13V/H15Q/E44D/V89D, I13V/S39I/E44D/Q82R/V89D, I13V/E44D/Q82R/V89D, I13V/Q72H/R76G/I86T, I13V/H15Q/R76G/I85F, H15Q/S39I/R76G/V89D, H15Q/S67L/R76G/I85F, H15Q/T47A/Q72H/R76G/I86T, H15Q/T47A/Q72H/R76G, I13V/H15Q/T47A/Q72H/R76G, H15Q/E44D/R76G/I85F, H15Q/S39I/S67L/V89D, H15Q/N32D/S67L/V89D, N32D/S67L/V89D, H15Q/S67L/Q72H/R76G/V89D, H15Q/Q72H/Q74R/R76G/I86T, G28V/Q72H/R76G/I86T, I13V/H15Q/S39I/E44D/S67L, E44D/S67L/Q72H/Q82R/V89D, H15Q/V89D, H15Q/T47A, I13V/H15Q/Q82R, I13V/H15Q/V89D, I13V/S67L/Q82R/V89D, I13V/H15Q/Q82R/V89D, H15Q/V31M/S67L/Q82R/V89D, I13V/H15Q/T47A/Q82R, I13V/H15Q/V31A/N45S/Q82R/V89D, H15Q/T47A/H69L/Q82R/V89D, I13V/H15Q/T47A/H69L/R76G/V89D, I12V/I13V/H15Q/T47A/Q82R/V89D, I13V/H15Q/R76G/D77N/Q82R/V89D, I13V/H15Q/T47A/R76G/V89D, I13V/H15Q/T47A/Q82R/V89D, I13V/H15Q/N24D/Q82R/V89D, I13V/H15Q/I36V/T47A/S67L/V89D, H15Q/T47A/K65R/S67L/Q82R/V89D, H15Q/L33P/T47A/S67L/P71S/V89D, I13V/H15Q/Q72H/R76G/I86T, H15Q/T47A/S67L/Q82R/V89D, F2L/H15Q/D46E/T47A/Q72H/R76G/Q82R/V89D, I13V/H15Q/L33F/T47A/Q82R/V89D, I13V/H15Q/T47A/E58G/S67L/Q82R/V89D, H15Q/N24S/T47A/Q72H/R76G/V89D, I13V/H15Q/E44V/T47A/Q82R/V89D, H15Q/N18D/T47A/Q72H/V73A/R76G/I86T/V89D, I13V/H15Q/T37A/E44D/S48C/S67L/Q82R/V89D, H15Q/L33H/S67L/R76G/Q82R/V89D, I13V/H15Q/T47A/Q72H/R76G/I86T, H15Q/S39I/E44D/Q72H/V75G/R76G/Q82R/V89D, H15Q/T47A/S67L/R76G/Q82R/V89D, or I13V/H15Q/T47A/S67L/Q72H/R76G/Q82R/V89D.


In some embodiments, the variant PD-L2 polypeptide comprises amino acid modifications in an unmodified PD-L2 or specific binding fragment thereof at a position corresponding to position 13, with reference to positions set forth in SEQ ID NO: 31. In some embodiments, the amino acid modification is the amino acid substitution I13V or a conservative amino acid substitution thereof. In some embodiments, the variant PD-L2 polypeptide further contains one or more amino acid modifications, e.g. amino acid substitutions, at one or more positions 15, 44, 47, 67, 72, 72, 76, 82, 86 or 89. In some embodiments, the one or more amino acid modification is one or more amino acid substitutions H15Q, E44D, T47A, S67L, Q72H, R76G, Q82R, I86T, V89D, or a conservative amino acid substitution thereof. In some embodiments, the variant PD-L2 polypeptide comprises the amino acid modifications I13V/H15Q, I13V/E44D, I13V/T47A, I13V/S67L, I13V/Q72H, I13V/R76G, I13V/Q82R, I13V/I86T or I13V/V89D.


In some embodiments, the variant PD-L2 polypeptide comprises amino acid modifications in an unmodified PD-L2 or specific binding fragment thereof at a position corresponding to position 15, with reference to positions set forth in SEQ ID NO: 31. In some embodiments, the amino acid modification is the amino acid substitution H15Q or a conservative amino acid substitution thereof. In some embodiments, the variant PD-L2 polypeptide further contains one or more amino acid modifications, e.g. amino acid substitutions, at one or more positions 13, 44, 47, 67, 72, 72, 76, 82, 86 or 89. In some embodiments, the one or more amino acid modification is one or more amino acid substitutions I13V, E44D, T47A, S67L, Q72H, R76G, Q82R, I86T, V89D, or a conservative amino acid substitution thereof. In some embodiments, the variant PD-L2 polypeptide comprises the amino acid modifications I13V/H15Q, H15Q/E44D, H15Q/T47A, H15Q/S67L, H15Q/Q72H, H15Q/R76G, H15Q/Q82R, H15Q/I86T or H15Q/V89D. In some embodiments, the variant PD-L2 polypeptide comprises the amino acid modifications H15Q/S62L/Q82R, H15Q/S62L/V89D, or H15Q/Q82R/V89D.


In some embodiments, the variant PD-L2 polypeptide comprises amino acid modifications in an unmodified PD-L2 or specific binding fragment thereof at a position corresponding to position 47, with reference to positions set forth in SEQ ID NO: 31. In some embodiments, the amino acid modification is the amino acid substitution T47A or a conservative amino acid substitution thereof. In some embodiments, the variant PD-L2 polypeptide further contains one or more amino acid modifications, e.g. amino acid substitutions, at one or more positions 13, 15, 44, 67, 72, 72, 76, 82, 86 or 89. In some embodiments, the one or more amino acid modification is one or more amino acid substitutions I13V, H15Q, E44D, S67L, Q72H, R76G, Q82R, I86T, V89D, or a conservative amino acid substitution thereof. In some embodiments, the variant PD-L2 polypeptide comprises the amino acid modifications I13V/T47A, H15Q/T47A, T47A/E44D, T47A/S67L, T47A/Q72H, T47A/R76G, T47A/Q82R, T47A/I86T or T47A/V89D.


In some embodiments, the variant PD-L2 polypeptide comprises amino acid modifications in an unmodified PD-L2 or specific binding fragment thereof at a position corresponding to position 67, with reference to positions set forth in SEQ ID NO: 31. In some embodiments, the amino acid modification is the amino acid substitution S67L or a conservative amino acid substitution thereof. In some embodiments, the variant PD-L2 polypeptide further contains one or more amino acid modifications, e.g. amino acid substitutions, at one or more positions 13, 15, 44, 47, 72, 72, 76, 82, 86 or 89. In some embodiments, the one or more amino acid modification is one or more amino acid substitutions I13V, H15Q, E44D, T47A, Q72H, R76G, Q82R, I86T, V89D, or a conservative amino acid substitution thereof. In some embodiments, the variant PD-L2 polypeptide comprises the amino acid modifications I13V/S67L, H15Q/S67L, S67L/E44D, T47A/S67L, S67L/Q72H, S67L/R76G, S67L/Q82R, S67L/I86T or S67L/V89D. In some embodiments, the variant PD-L2 polypeptide comprises the amino acid modifications H15Q/S62L/Q82R, H15Q/S62L/V89D, or S62L/Q82R/V89D.


In some embodiments, the variant PD-L2 polypeptide comprises amino acid modifications in an unmodified PD-L2 or specific binding fragment thereof at a position corresponding to position 72, with reference to positions set forth in SEQ ID NO: 31. In some embodiments, the amino acid modification is the amino acid substitution Q72H or a conservative amino acid substitution thereof. In some embodiments, the variant PD-L2 polypeptide further contains one or more amino acid modifications, e.g. amino acid substitutions, at one or more positions 13, 15, 44, 47, 67, 76, 82, 86 or 89. In some embodiments, the one or more amino acid modification is one or more amino acid substitutions I13V, H15Q, E44D, T47A, S67L, R76G, Q82R, I86T, V89D, or a conservative amino acid substitution thereof. In some embodiments, the variant PD-L2 polypeptide comprises the amino acid modifications I13V/Q72H, H15Q/Q72H, Q72H/E44D, T47A/Q72H, S67L/Q72H, Q72H/R76G, Q72H/Q82R, Q72H/I86T or Q72H/V89D.


In some embodiments, the variant PD-L2 polypeptide comprises amino acid modifications in an unmodified PD-L2 or specific binding fragment thereof at a position corresponding to position 76, with reference to positions set forth in SEQ ID NO: 31. In some embodiments, the amino acid modification is the amino acid substitution R76G or a conservative amino acid substitution thereof. In some embodiments, the variant PD-L2 polypeptide further contains one or more amino acid modifications, e.g. amino acid substitutions, at one or more positions 13, 15, 44, 47, 67, 72, 82, 86 or 89. In some embodiments, the one or more amino acid modification is one or more amino acid substitutions I13V, H15Q, E44D, T47A, S67L, Q72H, Q82R, I86T, V89D, or a conservative amino acid substitution thereof. In some embodiments, the variant PD-L2 polypeptide comprises the amino acid modifications I13V/R76G, H15Q/R76G, E44D/R76G, T47A/R76G, S67L/R76G, Q72H/R76G, R76G/Q82R, R76G/I86T or R76G/V89D.


In some embodiments, the variant PD-L2 polypeptide comprises amino acid modifications in an unmodified PD-L2 or specific binding fragment thereof at a position corresponding to position 82, with reference to positions set forth in SEQ ID NO: 31. In some embodiments, the amino acid modification is the amino acid substitution Q82R or a conservative amino acid substitution thereof. In some embodiments, the variant PD-L2 polypeptide further contains one or more amino acid modifications, e.g. amino acid substitutions, at one or more positions 13, 15, 44, 47, 67, 72, 76, 86 or 89. In some embodiments, the one or more amino acid modification is one or more amino acid substitutions I13V, H15Q, E44D, T47A, S67L, Q72H, R76G, I86T, V89D, or a conservative amino acid substitution thereof. In some embodiments, the variant PD-L2 polypeptide comprises the amino acid modifications I13V/Q82R, H15Q/Q82R, E44D/Q82R, T47A/Q82R, S67L/Q82A, Q72H/Q82R, R76G/Q82R, Q82R/I86T or Q86R/V89D.


In some embodiments, the variant PD-L2 polypeptide comprises amino acid modifications in an unmodified PD-L2 or specific binding fragment thereof at a position corresponding to position 86, with reference to positions set forth in SEQ ID NO: 31. In some embodiments, the amino acid modification is the amino acid substitution I86T or a conservative amino acid substitution thereof. In some embodiments, the variant PD-L2 polypeptide further contains one or more amino acid modifications, e.g. amino acid substitutions, at one or more positions 13, 15, 44, 47, 67, 72, 76, 82 or 89. In some embodiments, the one or more amino acid modification is one or more amino acid substitutions I13V, H15Q, E44D, T47A, S67L, Q72H, R76G, Q82R, V89D, or a conservative amino acid substitution thereof. In some embodiments, the variant PD-L2 polypeptide comprises the amino acid modifications I13V/I86T, H15Q/I86T, E44D/I86T, T47A/I86T, S67L/I86T, Q72H/I86T, R76G/I86T, Q82R/I86T or I86T/V89D.


In some embodiments, the variant PD-L2 polypeptide comprises amino acid modifications in an unmodified PD-L2 or specific binding fragment thereof at a position corresponding to position 89, with reference to positions set forth in SEQ ID NO: 31. In some embodiments, the amino acid modification is the amino acid substitution V89D or a conservative amino acid substitution thereof. In some embodiments, the variant PD-L2 polypeptide further contains one or more amino acid modifications, e.g. amino acid substitutions, at one or more positions 13, 15, 44, 47, 67, 72, 76, 82 or 86. In some embodiments, the one or more amino acid modification is one or more amino acid substitutions I13V, H15Q, E44D, T47A, S67L, Q72H, R76G, Q82R, I86T, or a conservative amino acid substitution thereof. In some embodiments, the variant PD-L2 polypeptide comprises the amino acid modifications I13V/V89D, H15Q/V89D, E44D/V89D, T47A/V89D, S67L/V89D, Q72H/V89D, R76H/V89D, I86T/V89D. In some embodiments, the variant PD-L2 polypeptide comprises the amino acid modifications H15Q/S62L/V89D, H15Q/Q82R/V89D, or S62L/Q82R/V89D.


In some embodiments, the variant PD-L2 polypeptide comprises any of the substitutions (mutations) listed in Table 1. Table 1 also provides exemplary sequences by reference to SEQ ID NO for the extracellular domain (ECD) or IgV domain of wild-type PD-L2 or exemplary variant PD-L2 polypeptides. As indicated, the exact locus or residues corresponding to a given domain can vary, such as depending on the methods used to identify or classify the domain. Also, in some cases, adjacent N- and/or C-terminal amino acids of a given domain (e.g. IgV) also can be included in a sequence of a variant IgSF polypeptide, such as to ensure proper folding of the domain when expressed. Thus, it is understood that the exemplification of the SEQ ID NOS in Table 1 is not to be construed as limiting. For example, the particular domain, such as the IgV domain, of a variant PD-L2 polypeptide can be several amino acids longer or shorter, such as 1-10, e.g. 1, 2, 3, 4, 5, 6 or 7 amino acids longer or shorter, than the sequence of amino acids set forth in the respective SEQ ID NO.


In some embodiments, the variant PD-L2 polypeptide comprises any of the mutations listed in Table 1. Table 1 also provides exemplary sequences by reference to SEQ ID NO for the extracellular domain (ECD) or IgV domain of wild-type PD-L2 or exemplary variant PD-L2 polypeptides. As indicated, the exact locus or residues corresponding to a given domain can vary, such as depending on the methods used to identify or classify the domain. Also, in some cases, adjacent N- and/or C-terminal amino acids of a given domain (e.g. IgV) also can be included in a sequence of a variant IgSF polypeptide, such as to ensure proper folding of the domain when expressed. Thus, it is understood that the exemplification of the SEQ ID NOs in Table 1 is not to be construed as limiting. For example, the particular domain, such as the IgV domain, of a variant PD-L2 polypeptide can be several amino acids longer or shorter, such as 1-10, e.g. 1, 2, 3, 4, 5, 6 or 7 amino acids longer or shorter, than the sequence of amino acids set forth in the respective SEQ ID NO.


In some embodiments, the variant PD-L2 polypeptide comprises any of the mutations listed in Table 1.


In some embodiments, the variant PD-L2 polypeptide comprises or consists of any of the extracellular domain (ECD) sequences listed in Table 1 (i.e., any one of SEQ ID NOS: 56-106, 108-114 and 116-132). In some embodiments, the variant PD-L2 polypeptide comprises or consists of a polypeptide sequence that exhibits at least 90% identity, at least 91% identity, at least 92% identity, at least 93% identity, at least 94% identity, at least 95% identity, such as at least 96% identity, 97% identity, 98% identity, or 99% identity to any of the extracellular domain (ECD) sequences listed in Table 1 (i.e., any one of SEQ ID NOS: 56-106, 108-114 and 116-132) and contains the amino acid modification(s), e.g. substitution(s) not present in the wild-type or unmodified PD-L2. In some embodiments, the variant PD-L2 polypeptide comprises or consists of a specific binding fragment of any of the extracellular domain (ECD) sequences listed in Table 1 (i.e., any one of SEQ ID NOS: 56-106, 108-114 and 116-132) and contains the amino acid modification(s), e.g. substitution(s) not present in the wild-type or unmodified PD-L2.


In some embodiments, the variant PD-L2 polypeptide comprises or consists of any of the IgV sequences listed in Table 1 (i.e., any one of SEQ ID NOS: 133-183, 185-191, 193-209, 268-318, 320-343). In some embodiments, the variant PD-L2 polypeptide comprises or consists of a polypeptide sequence that exhibits at least 90% identity, at least 91% identity, at least 92% identity, at least 93% identity, at least 94% identity, at least 95% identity, such as at least 96% identity, 97% identity, 98% identity, or 99% identity to any of the IgV sequences listed in Table 1 (i.e., any one of SEQ ID NOS: 133-183, 185-191, 193-209, 268-318, 320-343) and contains the amino acid substitution(s) not present in the wild-type or unmodified PD-L2. In some embodiments, the variant PD-L2 polypeptide comprises or consists of a specific binding fragment of any of the IgV sequences listed in Table 1 (i.e., any one of SEQ ID NOS: 133-183, 185-191, 193-209, 268-318, 320-343) and contains the amino acid modification(s), e.g. substitution(s) not present in the wild-type or unmodified PD-L2.









TABLE 1







Exemplary variant PD-L2 polypeptides










ECD SEQ ID
IgV SEQ ID


Mutation(s)
NO
NO












Wild-type
31
55, 115


H15Q
56
133, 268


N24D
57
134, 269


E44D
58
135, 270


V89D
59
136, 271


Q82R/V89D
60
137, 272


E59G/Q82R
61
138, 273


S39I/V89D
62
139, 274


S67L/V89D
63
140, 275


S67L/I85F
64
141, 276


S67L/I86T
65
142, 277


H15Q/K65R
66
143, 278


H15Q/Q72H/V89D
67
144, 279


H15Q/S67L/R76G
68
145, 280


H15Q/R76G/I85F
69, 74
146, 281,




151, 186


H15Q/T47A/Q82R
70
147, 282


H15Q/Q82R/V89D
71
148, 283


H15Q/C23S/I86T
72
149, 284


H15Q/S39I/I86T
73
150, 285


E44D/V89D/W91R
75
152, 287


I13V/S67L/V89D
76
153, 288


H15Q/S67L/I86T
77
154, 289


I13V/H15Q/S67L/I86T
78
155, 290


I13V/H15Q/E44D/V89D
79
156, 291


I13V/S39I/E44D/Q82R/V89D
80
157, 292


I13V/E44D/Q82R/V89D
81
158, 293


I13V/Q72H/R76G/I86T
82
159, 294


I13V/H15Q/R76G/I85F
83
160, 295


H15Q/S39I/R76G/V89D
84
161, 296


H15Q/S67L/R76G/I85F
85
162, 297


H15Q/T47A/Q72H/R76G/I86T
86
163, 298


H15Q/T47A/Q72H/R76G
87
164, 299


I13V/H15Q/T47A/Q72H/R76G
88
165, 300


H15Q/E44D/R76G/I85F
89
166, 301


H15Q/S39I/S67L/V89D
90
167, 302


H15Q/N32D/S67L/V89D
91
168, 303


N32D/S67L/V89D
92
169, 304


H15Q/S67L/Q72H/R76G/V89D
93
170, 305


H15Q/Q72H/Q74R/R76G/I86T
94
171, 306


G28V/Q72H/R76G/I86T
95
172, 307


I13V/H15Q/S39I/E44D/S67L
96
173, 308


E44D/S67L/Q72H/Q82R/V89D
97
174, 309


H15Q/V89D
98
175, 310


H15Q/T47A
99
176, 311


I13V/H15Q/Q82R
100
177, 312


I13V/H15Q/V89D
101
178, 313


I13V/S67L/Q82R/V89D
102
179, 314


I13V/H15Q/Q82R/V89D
103
180, 315


H15Q/V31M/S67L/Q82R/V89D
104
181, 316


I13V/H15Q/T47A/Q82R
105
182, 317


I13V/H15Q/V31A/N45S/Q82R/V89D
106
183, 318


H15Q/T47A/H69L/Q82R/V89D
108
185, 320


I13V/H15Q/T47A/H69L/R76G/V89D
109
186, 321


I12V/I13V/H15Q/T47A/Q82R/V89D
110
187, 322


I13V/H15Q/R76G/D77N/Q82R/V89D
111
188, 323


I13V/H15Q/T47A/R76G/V89D
112
189, 324


I13V/H15Q/T47A/Q82R/V89D
113
190, 325


I13V/H15Q/N24D/Q82R/V89D
114
191, 326


I13V/H15Q/I36V/T47A/S67L/V89D
116
193, 327


H15Q/T47A/K65R/S67L/Q82R/V89D
117
194, 328


H15Q/L33P/T47A/S67L/P71S/V89D
118
195, 329


I13V/H15Q/Q72H/R76G/I86T
119
196, 330


H15Q/T47A/S67L/Q82R/V89D
120
197, 331


F2L/H15Q/D46E/T47A/Q72H/R76G/
121
198, 332


Q82R/V89D




I13V/H15Q/L33F/T47A/Q82R/V89D
122
199, 333


I13V/H15Q/T47A/E58G/S67L/Q82R/V89D
123
200, 334


H15Q/N24S/T47A/Q72H/R76G/V89D
124
201, 335


I13V/H15Q/E44V/T47A/Q82R/V89D
125
202, 336


H15Q/N18D/T47A/Q72H/V73A/R76G/
126
203, 337


I86T/V89D




I13V/H15Q/T37A/E44D/S48C/S67L/
127
204, 338


Q82R/V89D




H15Q/L33H/S67L/R76G/Q82R/V89D
128
205, 339


I13V/H15Q/T47A/Q72H/R76G/I86T
129
206, 340


H15Q/S39I/E44D/Q72H/V75G/R76G/
130
207, 341


Q82R/V89D




H15Q/T47A/S67L/R76G/Q82R/V89D
131
208, 342


I13V/H15Q/T47A/S67L/Q72H/R76G/
132
209, 343


Q82R/V89D









In some embodiments, the variant PD-L2 polypeptide exhibits increased affinity for the ectodomain of PD-1 compared to the wild-type or unmodified PD-L2 polypeptide, such as comprising the sequence set forth in SEQ ID NO: 31, 55 or 115. In some embodiments, the PD-L2 polypeptide exhibits increased affinity for the ectodomain of RGMb compared to the wild-type or unmodified PD-L2, such as comprising the sequence set forth in SEQ ID NO: 31, 55 or 115. In some embodiments, the PD-L2 polypeptide exhibits increased affinity for the ectodomain of PD-1 and the ectodomain of RGMb compared to the wild-type or unmodified PD-L2, such as comprising the sequence set forth in SEQ ID NO: 31, 55 or 115.


In some embodiments, the variant PD-L2 polypeptide exhibits increased binding affinity for binding one of the ectodomains of PD-1 or RGMb and exhibits decreased binding affinity for binding to the other of the ectodomains of PD-1 or RGMb compared to the wild-type or unmodified PD-L2 polypeptide, such as comprising the sequence set forth in SEQ ID NO: 31, 55 or 115. In some embodiments, the variant PD-L2 polypeptide exhibits increased affinity for the ectodomain of PD-1, and decreased affinity for the ectodomain of RGMb, compared to wild-type or unmodified PD-L2 polypeptide, such as comprising the sequence set forth in SEQ ID NO: 31, 55 or 115. In some embodiments, the variant PD-L2 polypeptide exhibits increased affinity for the ectodomain of RGMb and decreased affinity for the ectodomain of PD-1, compared to wild-type or unmodified PD-L2 polypeptide, such as comprising the sequence set forth in SEQ ID NO: 31, 55 or 115.


In some embodiments, a variant PD-L2 polypeptide exhibits increased selectivity for PD-1 versus RGMb or other cognate binding partner of PD-L2 compared to the ratio of binding of the unmodified PD-L2 polypeptide, e.g. set forth in SEQ ID NO: 31, 55 or 115, for binding RGMb or other cognate binding partner. In some embodiments, the ratio of PD-1 binding to RGMb binding (PD-1: RGMb binding ratio) is greater than 1. In some embodiments, the variant PD-L2 polypeptide exhibits a ratio of binding PD-1 versus RGMb or other cognate binding partner that is greater than or greater than about or 1.1, 1.2, 1.3, 1.4, 1.5, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 35, 40, 45, 50, 55, 60, 65, 70, or more.


III. FORMAT OF VARIANT POLYPEPTIDES

The immunomodulatory polypeptide comprising a variant PD-L2 provided herein in which is contained a vIgD can be formatted in a variety of ways, including as a soluble protein, membrane bound protein or secreted protein. In some embodiments, the particular format can be chosen for the desired therapeutic application. In some cases, an immunomodulatory polypeptide comprising a variant PD-L2 polypeptide is provided in a format to antagonize or block activity of its cognate binding partner, e.g. PD-1. In some embodiments, antagonism of PD-1 may be useful to promote immunity in oncology. In some cases, an immunomodulatory polypeptide comprising a variant PD-L2 polypeptide is provided in a format to agonize or stimulate activity of its cognate binding partner, e.g. PD-1. In some embodiments, agonism of PD-1 may be useful for treating inflammation or autoimmunity. A skilled artisan can readily determine the activity of a particular format, such as for antagonizing or agonizing one or more specific cognate binding partner. Exemplary methods for assessing such activities are provided herein, including in the examples.


In some aspects, provided are immunomodulatory proteins comprising a vIgD of PD-L2 in which such proteins are soluble, e.g. fused to an Fc chain. In some aspects, one or more additional IgSF domain, such as one or more additional vIgD, may be linked to a vIgD of PD-L2 as provided herein (hereinafter called a “stack” or “stacked” immunomodulatory protein). In some embodiments, the modular format of the provided immunomodulatory proteins provides flexibility for engineering or generating immunomodulatory proteins for modulating activity of multiple counter structures (multiple cognate binding partners). In some embodiments, such “stack” molecules can be provided in a soluble format or, in some cases, may be provided as membrane bound or secreted proteins. In some embodiments, a variant PD-L2 immunomodulatory protein is provided as a conjugate in which is contained a vIgD of PD-L2 linked, directly or indirectly, to a targeting agent or moiety, e.g. to an antibody or other binding molecules that specifically binds to a ligand, e.g. an antigen, for example, for targeting or localizing the vIgD to a specific environment or cell, such as when administered to a subject. In some embodiments, the targeting agent, e.g. antibody or other binding molecule, binds to a tumor antigen, thereby localizing the variant PD-L2 containing the vIgD to the tumor microenvironment, for example, to modulate activity of tumor infiltrating lymphocytes (TILs) specific to the tumor microenvironment.


In some embodiments, provided immunomodulatory proteins are expressed in cells and provided as part of an engineered cellular therapy (ECT). In some embodiments, the variant PD-L2 polypeptide is expressed in a cell, such as an immune cell (e.g. T cell or antigen presenting cell), in membrane-bound form, thereby providing a transmembrane immunomodulatory protein (hereinafter also called a “TIP”). In some embodiments, depending on the cognate binding partner recognized by the TIP, engineered cells expressing a TIP can agonize a cognate binding partner by providing a costimulatory signal, either positive to negative, to other engineered cells and/or to endogenous T cells. In some aspects, the variant PD-L2 polypeptide is expressed in a cell, such as an immune cell (e.g. T cell or antigen presenting cell), in secretable form to thereby produce a secreted or soluble form of the variant PD-L2 polypeptide (hereinafter also called a “SIP”), such as when the cells are administered to a subject. In some aspects, a SIP can antagonize a cognate binding partner in the environment (e.g. tumor microenvironment) in which it is secreted. In some embodiments, a variant PD-L2 polypeptide is expressed in an infectious agent (e.g. viral or bacterial agent) which, upon administration to a subject, is able to infect a cell in vivo, such as an immune cell (e.g. T cell or antigen presenting cell), for delivery or expression of the variant polypeptide as a TIP or a SIP in the cell.


In some embodiments, a soluble immunomodulatory polypeptide, such as a variant PD-L2 containing a vIgD, can be encapsulated within a liposome which itself can be conjugated to any one of or any combination of the provided conjugates (e.g., a targeting moiety). In some embodiments, the soluble or membrane bound immunomodulatory polypeptides of the invention are deglycosylated. In more specific embodiments, the variant PD-L2 sequence is deglycosylated. In even more specific embodiments, the IgV and/or IgC (e.g. IgC2) domain or domains of the variant PD-L2 is deglycosylated.


Non-limiting examples of provided formats are described in FIGS. 1A-1C and further described below.


A. Soluble Protein


In some embodiments, the immunomodulatory protein containing a variant PD-L2 polypeptide is a soluble protein. Those of skill will appreciate that cell surface proteins typically have an intracellular, transmembrane, and extracellular domain (ECD) and that a soluble form of such proteins can be made using the extracellular domain or an immunologically active subsequence thereof. Thus, in some embodiments, the immunomodulatory protein containing a variant PD-L2 polypeptide lacks a transmembrane domain or a portion of the transmembrane domain. In some embodiments, the immunomodulatory protein containing a variant PD-L2 lacks the intracellular (cytoplasmic) domain or a portion of the intracellular domain. In some embodiments, the immunomodulatory protein containing the variant PD-L2 polypeptide only contains the vIgD portion containing the ECD domain or a portion thereof containing an IgV domain and/or IgC (e.g. IgC2) domain or domains or specific binding fragments thereof containing the amino acid modification(s).


In some embodiments, the immunomodulatory protein is or contains a variant PD-L2 polypeptide that is in monomer form and/or that exhibits monovalent binding to its binding partner. In some aspects, a variant PD-L2 polypeptide as described, such as a variant PD-L2 that is soluble and/or that lacks a transmembrane domain and intracellular signaling domain, is linked, directly or indirectly, to a further moiety. In some embodiments, the further moiety is a protein, peptide, small molecule or nucleic acid. In some embodiments, the monovalent immunomodulatory protein is a fusion protein. In some embodiments, the moiety is a half-life extending molecule. Exemplary of such half-life extending molecules include, but are not limited to, albumin, an albumin-binding polypeptide, Pro/Ala/Ser (PAS), a C-terminal peptide (CTP) of the beta subunit of human chorionic gonadotropin, polyethylene glycol (PEG), long unstructured hydrophilic sequences of amino acids (XTEN), hydroxyethyl starch (HES), an albumin-binding small molecule, or a combination thereof.


In some embodiments, the immunomodulatory polypeptide comprising a variant PD-L2 can be linked to a moiety that includes conformationally disordered polypeptide sequences composed of the amino acids Pro, Ala, and Ser (See e.g., WO2008/155134, SEQ ID NO: 2033). In some cases, the amino acid repeat is at least 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 or more amino acid residues, wherein each repeat comprises (an) Ala, Ser, and Pro residue(s). Thus, provided herein is an immunomodulatory protein is a PASylated protein wherein the variant PD-L1 polypeptide is linked, directly or indirectly via a linker, to Pro/Ala/Ser (PAS). In some embodiments, one or more additional linker structures may be used.


In some embodiments, the moiety facilitates detection or purification of the variant PD-L2 polypeptide. In some cases, the immunomodulatory polypeptide comprises a tag or fusion domain, e.g. affinity or purification tag, linked, directly or indirectly, to the N- and/or c-terminus of the PD-L2 polypeptide. Various suitable polypeptide tags and/or fusion domains are known, and include but are not limited to, a poly-histidine (His) tag, a FLAG-tag (SEQ ID NO: 2034), a Myc-tag, and fluorescent protein-tags (e.g., EGFP, set forth in SEQ ID NOs: 2035-2037). In some cases, the immunomodulatory polypeptide comprising a variant PD-L2 comprises at least six histidine residues (set forth in SEQ ID NO: 1253). In some cases, the immunomodulatory polypeptide comprising a variant PD-L2 further comprises various combinations of moieties. For example, the immunomodulatory polypeptide comprising a variant PD-L2 further comprises one or more polyhistidine-tag and FLAG tag.


In some embodiments, the PD-L2 polypeptide is linked to a modified immunoglobulin heavy chain constant region (Fc) that remains in monovalent form such as set forth in SEQ ID NO: 1187.


In some embodiments, the immunomodulatory protein contains a variant PD-L2 polypeptide that is linked, directly or indirectly via a linker to a multimerization domain. In some aspects, the multimerization domain increases half-life of the molecule. Interaction of two or more variant PD-L2 polypeptides can be facilitated by their linkage, either directly or indirectly, to any moiety or other polypeptide that are themselves able to interact to form a stable structure. For example, separate encoded variant PD-L2 polypeptide chains can be joined by multimerization, whereby multimerization of the polypeptides is mediated by a multimerization domain. Typically, the multimerization domain provides for the formation of a stable protein-protein interaction between a first variant PD-L2 polypeptide and a second variant PD-L2 polypeptide.


Homo- or heteromultimeric polypeptides can be generated from co-expression of separate variant PD-L2 polypeptides. The first and second variant PD-L2 polypeptides can be the same or different. In particular embodiments, the first and second variant PD-L2 polypeptide are the same in a homodimer, and each are linked to a multimerization domain that is the same. In other embodiments, heterodimers can be formed by linking first and second variant PD-L2 polypeptides that are different. In such embodiments, in some aspects the first and second variant PD-L2 polypeptide are linked to different multimerization domains capable of promoting heterodimer formation.


In some embodiments, a multimerization domain includes any capable of forming a stable protein-protein interaction. The multimerization domains can interact via an immunoglobulin sequence (e.g. Fc domain; see e.g., International Patent Pub. Nos. WO 93/10151 and WO 2005/063816 US; U.S. Pub. No. 2006/0024298; U.S. Pat. No. 5,457,035); leucine zipper (e.g. from nuclear transforming proteins fos and jun or the proto-oncogene c-myc or from General Control of Nitrogen (GCN4)) (e.g., Busch and Sassone-Corsi (1990) Trends Genetics, 6:36-40; Gentz et al., (1989) Science, 243:1695-1699); a hydrophobic region; a hydrophilic region; or a free thiol which forms an intermolecular disulfide bond between the chimeric molecules of a homo- or heteromultimer. In addition, a multimerization domain can include an amino acid sequence comprising a protuberance complementary to an amino acid sequence comprising a hole, such as is described, for example, in U.S. Pat. No. 5,731,168; International Patent Pub. Nos. WO 98/50431 and WO 2005/063816; Ridgway et al. (1996) Protein Engineering, 9:617-621. Such a multimerization region can be engineered such that steric interactions not only promote stable interaction, but further promote the formation of heterodimers over homodimers from a mixture of chimeric monomers. Generally, protuberances are constructed by replacing small amino acid side chains from the interface of the first polypeptide with larger side chains (e.g., tyrosine or tryptophan). Compensatory cavities of identical or similar size to the protuberances are optionally created on the interface of the second polypeptide by replacing large amino acid side chains with smaller ones (e.g., alanine or threonine). Exemplary multimerization domains are described below.


The variant PD-L2 polypeptide can be joined anywhere, but typically via its N- or C-terminus, to the N- or C-terminus of a multimerization domain to form a chimeric polypeptide. The linkage can be direct or indirect via a linker. The chimeric polypeptide can be a fusion protein or can be formed by chemical linkage, such as through covalent or non-covalent interactions. For example, when preparing a chimeric polypeptide containing a multimerization domain, nucleic acid encoding all or part of a variant PD-L2 polypeptide can be operably linked to nucleic acid encoding the multimerization domain sequence, directly or indirectly or optionally via a linker domain. In some cases, the construct encodes a chimeric protein where the C-terminus of the variant PD-L2 polypeptide is joined to the N-terminus of the multimerization domain. In some instances, a construct can encode a chimeric protein where the N-terminus of the variant PD-L2 polypeptide is joined to the N- or C-terminus of the multimerization domain.


A polypeptide multimer contains multiple, such as two, chimeric proteins created by linking, directly or indirectly, two of the same or different variant PD-L2 polypeptides directly or indirectly to a multimerization domain. In some examples, where the multimerization domain is a polypeptide, a gene fusion encoding the variant PD-L2 polypeptide and multimerization domain is inserted into an appropriate expression vector. The resulting chimeric or fusion protein can be expressed in host cells transformed with the recombinant expression vector, and allowed to assemble into multimers, where the multimerization domains interact to form multivalent polypeptides. Chemical linkage of multimerization domains to variant PD-L2 polypeptides can be effected using heterobifunctional linkers.


The resulting chimeric polypeptides, such as fusion proteins, and multimers formed therefrom, can be purified by any suitable method such as, for example, by affinity chromatography over Protein A or Protein G columns. Where two nucleic acid molecules encoding different polypeptides are transformed into cells, formation of homo- and heterodimers will occur. Conditions for expression can be adjusted so that heterodimer formation is favored over homodimer formation.


In some embodiments, the multimerization domain is an Fc domain or portions thereof from an immunoglobulin. In some embodiments, the immunomodulatory protein comprises a variant PD-L2 polypeptide attached to an immunoglobulin Fc (yielding an “immunomodulatory Fc fusion,” such as a “PD-L2-Fc variant fusion,” also termed a PD-L2 vIgD-Fc fusion). In some embodiments, the attachment of the variant PD-L2 polypeptide is at the N-terminus of the Fc. In some embodiments, the attachment of the variant PD-L2 polypeptide is at the C-terminus of the Fc. In some embodiments, two or more PD-L2 variant polypeptides (the same or different) are independently attached at the N-terminus and at the C-terminus.


In some embodiments, the Fc is murine or human Fc. In some embodiments, the Fc is a mammalian or human IgG1, lgG2, lgG3, or lgG4 Fc regions. In some embodiments, the Fc is derived from IgG1, such as human IgG1. In some embodiments, the Fc comprises the amino acid sequence set forth in SEQ ID NO: 211 or a sequence of amino acids that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to SEQ ID NO: 211.


In some embodiments, the Fc region contains one more modifications to alter (e.g. reduce) one or more of its normal functions. In general, the Fc region is responsible for effector functions, such as complement-dependent cytotoxicity (CDC) and antibody-dependent cell cytotoxicity (ADCC), in addition to the antigen-binding capacity, which is the main function of immunoglobulins. In some cases, effector functions of an Fc region can include programmed cell death and cellular phagocytosis. Additionally, the FcRn sequence present in the Fc region plays the role of regulating the IgG level in serum by increasing the in vivo half-life by conjugation to an in vivo FcRn receptor. In some embodiments, such functions can be reduced or altered in an Fc for use with the provided Fc fusion proteins.


In some embodiments, one or more amino acid modifications may be introduced into the Fc region of a PD-L2-Fc variant fusion provided herein, thereby generating an Fc region variant. In some embodiments, the Fc region variant has decreased effector function. There are many examples of changes or mutations to Fc sequences that can alter effector function. For example, WO 00/42072, WO2006019447, WO2012125850, WO2015/107026, US2016/0017041 and Shields et al. J Biol. Chem. 9(2): 6591-6604 (2001) describe exemplary Fc variants with improved or diminished binding to FcRs. The contents of those publications are specifically incorporated herein by reference.


In some embodiments, the provided variant PD-L2-Fc fusions comprise an Fc region that exhibits reduced effector functions, which makes it a desirable candidate for applications in which the half-life of the PD-L2-Fc variant fusion in vivo is important yet certain effector functions (such as CDC and ADCC) are unnecessary or deleterious. In vitro and/or in vivo cytotoxicity assays can be conducted to confirm the reduction/depletion of CDC and/or ADCC activities. For example, Fc receptor (FcR) binding assays can be conducted to ensure that the PD-L2-Fc variant fusion lacks FcγR binding (hence likely lacking ADCC activity), but retains FcRn binding ability. The primary cells for mediating ADCC, NK cells, express FcγRIII only, whereas monocytes express FcγRI, FcγRII and FcγRIII. FcR expression on hematopoietic cells is summarized in Table 3 on page 464 of Ravetch and Kinet, Annu. Rev. Immunol. 9:457-492 (1991). Non-limiting examples of in vitro assays to assess ADCC activity of a molecule of interest is described in U.S. Pat. No. 5,500,362 (see, e.g. Hellstrom, I. et al. Proc. Nat'l Acad. Sci. USA 83:7059-7063 (1986)) and Hellstrom, I et al., Proc. Nat'l Acad. Sci. USA 82:1499-1502 (1985); U.S. Pat. No. 5,821,337 (see Bruggemann, M. et al., J Exp. Med. 166:1351-1361 (1987)). Alternatively, non-radioactive assay methods may be employed (see, for example, ACTI™ non-radioactive cytotoxicity assay for flow cytometry (CellTechnology, Inc. Mountain View, Calif.; and CytoTox 96™ non-radioactive cytotoxicity assay (Promega, Madison, Wis.). Useful effector cells for such assays include peripheral blood mononuclear cells (PBMC) and Natural Killer (NK) cells. Alternatively, or additionally, ADCC activity of the molecule of interest may be assessed in vivo, e.g., in an animal model such as that disclosed in Clynes et al. Proc. Nat'l Acad. Sci. USA 95:652-656 (1998). C1q binding assays may also be carried out to confirm that the PD-L2-Fc variant fusion is unable to bind C1q and hence lacks CDC activity. See, e.g., C1q and C3c binding ELISA in WO 2006/029879 and WO 2005/100402. To assess complement activation, a CDC assay may be performed (see, for example, Gazzano-Santoro et al., J. Immunol. Methods 202:163 (1996); Cragg, M. S. et al., Blood 101:1045-1052 (2003); and Cragg, M. S. and M. J. Glennie, Blood 103:2738-2743 (2004)). FcRn binding and in vivo clearance/half life determinations can also be performed using methods known in the art (see, e.g., Petkova, S. B. et al., Int'l. Immunol. 18(12):1759-1769 (2006)).


PD-L2-Fc variant fusions with reduced effector function include those with substitution of one or more of Fc region residues 238, 265, 269, 270, 297, 327 and 329 by EU numbering (U.S. Pat. No. 6,737,056). Such Fc mutants include Fc mutants with substitutions at two or more of amino acid positions 265, 269, 270, 297 and 327 by EU numbering, including the so-called “DANA” Fc mutant with substitution of residues 265 and 297 to alanine (U.S. Pat. No. 7,332,581).


In some embodiments, the Fc region of PD-L2-Fc variant fusions has an Fc region in which any one or more of amino acids at positions 234, 235, 236, 237, 238, 239, 270, 297, 298, 325, and 329 (indicated by EU numbering) are substituted with different amino acids compared to the native Fc region. Such alterations of Fc region are not limited to the above-described alterations, and include, for example, alterations such as deglycosylated chains (N297A and N297Q), IgG1-N297G, IgG1-L234A/L235A, IgG1-L234A/L235E/G237A, IgG1-A325A/A330S/P331S, IgG1-C226S/C229S, IgG1-C226S/C229S/E233P/L234V/L235A, IgG1-E233P/L234V/L235A/G236del/S267K, IgG1-L234F/L235E/P331S, IgG1-S267E/L328F, IgG2-V234A/G237A, IgG2-H268Q/V309L/A330S/A331S, IgG4-L235A/G237A/E318A, and IgG4-L236E described in Current Opinion in Biotechnology (2009) 20 (6), 685-691; alterations such as G236R/L328R, L235G/G236R, N325A/L328R, and N325LL328R described in WO 2008/092117; amino acid insertions at positions 233, 234, 235, and 237 (indicated by EU numbering); and alterations at the sites described in WO 2000/042072.


Certain Fc variants with improved or diminished binding to FcRs are described. (See, e.g., U.S. Pat. No. 6,737,056; WO 2004/056312, WO2006019447 and Shields et al., J. Biol. Chem. 9(2): 6591-6604 (2001).)


In some embodiments, there is provided a PD-L2-Fc variant fusion comprising a variant Fc region comprising one or more amino acid substitutions which increase half-life and/or improve binding to the neonatal Fc receptor (FcRn). Antibodies with increased half-lives and improved binding to FcRn are described in US2005/0014934A1 (Hinton et al.) or WO2015107026. Those antibodies comprise an Fc region with one or more substitutions therein which improve binding of the Fc region to FcRn. Such Fc variants include those with substitutions at one or more of Fc region residues: 238, 256, 265, 272, 286, 303, 305, 307, 311, 312, 317, 340, 356, 360, 362, 376, 378, 380, 382, 413, 424 or 434 by EU numbering, e.g., substitution of Fc region residue 434 (U.S. Pat. No. 7,371,826).


In some embodiments, the Fc region of a PD-L2-Fc variant fusion comprises one or more amino acid substitution E356D and M358L by EU numbering. In some embodiments, the Fc region of a PD-L2-Fc variant fusion comprises one or more amino acid substitutions C220S, C226S and/or C229S by EU numbering. In some embodiments, the Fc region of a PD-L2 variant fusion comprises one or more amino acid substitutions R292C and V302C. See also Duncan & Winter, Nature 322:738-40 (1988); U.S. Pat. Nos. 5,648,260; 5,624,821; and WO 94/29351 concerning other examples of Fc region variants.


In some embodiments, alterations are made in the Fc region that result in diminished C1q binding and/or Complement Dependent Cytotoxicity (CDC), e.g., as described in U.S. Pat. No. 6,194,551, WO 99/51642, and Idusogie et al., J. Immunol. 164: 4178-4184 (2000).


In some embodiments, there is provided a PD-L2-Fc variant fusion comprising a variant Fc region comprising one or more amino acid modifications, wherein the variant Fc region is derived from IgG1, such as human IgG1. In some embodiments, the variant Fc region is derived from the amino acid sequence set forth in SEQ ID NO: 211. In some embodiments, the Fc contains at least one amino acid substitution that is N82G by numbering of SEQ ID NO: 211 (corresponding to N297G by EU numbering). In some embodiments, the Fc further contains at least one amino acid substitution that is R77C or V87C by numbering of SEQ ID NO: 211 (corresponding to R292C or V302C by EU numbering). In some embodiments, the variant Fc region further comprises a C5S amino acid modification by numbering of SEQ ID NO: 211 (corresponding to C220S by EU numbering). For example, in some embodiments, the variant Fc region comprises the following amino acid modifications: V297G and one or more of the following amino acid modifications C220S, R292C or V302C by EU numbering (corresponding to N82G and one or more of the following amino acid modifications C5S, R77C or V87C with reference to SEQ ID NO:211), e.g. the Fc region comprises the sequence set forth in SEQ ID NO:1205. In some embodiments, the variant Fc region comprises one or more of the amino acid modifications C220S, L234A, L235E or G237A, e.g. the Fc region comprises the sequence set forth in SEQ ID NO:1206. In some embodiments, the variant Fc region comprises one or more of the amino acid modifications C220S, L235P, L234V, L235A, G236del or S267K, e.g. the Fc region comprises the sequence set forth in SEQ ID NO:1207. In some embodiments, the variant Fc comprises one or more of the amino acid modifications C220S, L234A, L235E, G237A, E356D or M358L, e.g. the Fc region comprises the sequence set forth in SEQ ID NO:1189.


In some embodiments, the Fc region lacks the C-terminal lysine corresponding to position 232 of the wild-type or unmodified Fc set forth in SEQ ID NO: 211 (corresponding to K447del by EU numbering). In some aspects, such an Fc region can additionally include one or more additional modifications, e.g. amino acid substitutions, such as any as described. Exemplary of such an Fc region is set forth in SEQ ID NO: 1737, 1738, 1739 or 1740.


In some embodiments, there is provided a PD-L2-Fc variant fusion comprising a variant Fc region in which the variant Fc comprises the sequence of amino acids set forth in any of SEQ ID NOS:1189, 1205, 1206, 1207, 1737, 1738, 1739 or 1740 or a sequence of amino acids that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to any of SEQ ID NOS: 1189, 1205, 1206, 1207, 1737, 1738, 1739 or 1740.


In some embodiments, the Fc is derived from IgG2, such as human IgG2. In some embodiments, the Fc comprises the amino acid sequence set forth in SEQ ID NO: 212 or a sequence of amino acids that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to SEQ ID NO: 212.


In some embodiments, the IgG4 Fc is a stabilized Fc in which the CH3 domain of human IgG4 is substituted with the CH3 domain of human IgG1 and which exhibits inhibited aggregate formation, an antibody in which the CH3 and CH2 domains of human IgG4 are substituted with the CH3 and CH2 domains of human IgG1, respectively, or an antibody in which arginine at position 409 indicated in the EU index proposed by Kabat et al. of human IgG4 is substituted with lysine and which exhibits inhibited aggregate formation (see e.g. U.S. Pat. No. 8,911,726. In some embodiments, the Fc is an IgG4 containing the S228P mutation, which has been shown to prevent recombination between a therapeutic antibody and an endogenous IgG4 by Fab-arm exchange (see e.g. Labrijin et al. (2009) Nat. Biotechnol., 27(8)767-71.) In some embodiments, the Fc comprises the amino acid sequence of hIgG4.


In some embodiments, the variant PD-L2 polypeptide is directly linked to the Fc sequence. In some embodiments, the variant PD-L2 polypeptide is indirectly linked to the Fc sequence, such as via a linker. In some embodiments, one or more “peptide linkers” link the variant PD-L2 polypeptide and the Fc domain. In some embodiments, a peptide linker can be a single amino acid residue or greater in length. In some embodiments, the peptide linker has at least one amino acid residue but is no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid residues in length. In some embodiments, the linker is three alanines (AAA). In some embodiments, the linker is a flexible linker. In some embodiments, the linker is (in one-letter amino acid code): GGGGS (“4GS” or “G4S”; SEQ ID NO:1742) or multimers of the 4GS linker, such as repeats of 2, 3, 4, or 5 4GS linkers, such as set forth in SEQ ID NO: 264 (2×GGGGS) or SEQ ID NO: 263 (3×GGGGS). In some embodiments, the linker (in one-letter amino acid code) is GSGGGGS (SEQ ID NO:1741). In some embodiments, the linker also can include a series of alanine residues alone or in addition to another peptide linker (such as a 4GS linker or multimer thereof). In some embodiments, the number of alanine residues in each series is: 2, 3, 4, 5, or 6 alanines. In some embodiments, the linker is a rigid linker. For example, the linker is an α-helical linker. In some embodiments, the linker is (in one-letter amino acid code): EAAAK or multimers of the EAAAK linker, such as repeats of 2, 3, 4, or 5 EAAAK linkers, such as set forth in SEQ ID NO: 2030 (1×EAAAK), SEQ ID NO: 2031 (3×EAAAK) or SEQ ID NO: 2032 (5×EAAAK). In some embodiments, the linker can further include amino acids introduced by cloning and/or from a restriction site, for example the linker can include the amino acids GS (in one-letter amino acid code) as introduced by use of the restriction site BAMHI. For example, in some embodiments, the linker (in one-letter amino acid code) is GSGGGGS (SEQ ID NO:1741), GS(G4S)3 (SEQ ID NO: 2040), or GS(G4S)5 (SEQ ID NO: 2041). In some examples, the linker is a 2×GGGGS followed by three alanines (GGGGSGGGGSAAA; SEQ ID NO: 265). In some cases, the immunomodulatory polypeptide comprising a variant PD-L2 comprises various combinations of peptide linkers.


In some embodiments, the variant PD-L2-Fc fusion protein is a dimer formed by two variant PD-L2 Fc polypeptides linked to an Fc domain. In some embodiments, the dimer is a homodimer in which the two variant PD-L2 Fc polypeptides are the same. In some embodiments, the dimer is a heterodimer in which the two variant PD-L2 Fc polypeptides are different.


Also provided are nucleic acid molecules encoding the variant PD-L2-Fc fusion protein. In some embodiments, for production of an Fc fusion protein, a nucleic acid molecule encoding a variant PD-L2-Fc fusion protein is inserted into an appropriate expression vector. The resulting variant PD-L2-Fc fusion protein can be expressed in host cells transformed with the expression where assembly between Fc domains occurs by interchain disulfide bonds formed between the Fc moieties to yield dimeric, such as divalent, variant PD-L2-Fc fusion proteins.


The resulting Fc fusion proteins can be easily purified by affinity chromatography over Protein A or Protein G columns. For the generation of heterodimers, additional steps for purification can be necessary. For example, where two nucleic acids encoding different variant PD-L2 polypeptides are transformed into cells, the formation of heterodimers must be biochemically achieved since variant PD-L2 molecules carrying the Fc-domain will be expressed as disulfide-linked homodimers as well. Thus, homodimers can be reduced under conditions that favor the disruption of interchain disulfides, but do no effect intra-chain disulfides. In some cases, different variant-PD-L2 Fc monomers are mixed in equimolar amounts and oxidized to form a mixture of homo- and heterodimers. The components of this mixture are separated by chromatographic techniques. Alternatively, the formation of this type of heterodimer can be biased by genetically engineering and expressing Fc fusion molecules that contain a variant PD-L2 polypeptide using knob-into-hole methods described below.


B. Stack Molecules with Additional IgSF Domains


In some embodiments, the immunomodulatory proteins can contain any of the variant PD-L2 polypeptides provided herein linked, directly or indirectly, to one or more other immunoglobulin superfamily (IgSF) domain (“stacked” immunomodulatory protein construct and also called a “Type II” immunomodulatory protein). In some aspects, this can create unique multi-domain immunomodulatory proteins that bind two or more, such as three or more, cognate binding partners, thereby providing a multi-targeting modulation of the immune synapse.


In some embodiments, an immunomodulatory protein comprises a combination (a “non-wild-type combination”) and/or arrangement (a “non-wild type arrangement” or “non-wild-type permutation”) of a variant PD-L2 domain with one or more other affinity modified and/or non-affinity modified IgSF domain sequences of another IgSF family member (e.g. a mammalian IgSF family member) that are not found in wild-type IgSF family members. In some embodiments, the immunomodulatory protein contains 2, 3, 4, 5 or 6 immunoglobulin superfamily (IgSF) domains, where at least one of the IgSF domain is a variant PD-L2 IgSF domain (vIgD of PD-L2) according to the provided description.


In some embodiments, the sequences of the additional IgSF domains can be a modified IgSF domain that contains one or more amino acid modifications, e.g. substitutions, compared to a wildtype or unmodified IgSF domain. In some embodiments, the IgSF domain can be non-affinity modified (e.g., wild-type) or have been affinity modified. In some embodiments, the unmodified or wild-type IgSF domain can be from mouse, rat, cynomolgus monkey, or human origin, or combinations thereof. In some embodiments, the additional IgSF domains can be an IgSF domain of an IgSF family member set forth in Table 2. In some embodiments, the additional IgSF domain can be an affinity-modified IgSF domain containing one or more amino acid modifications, e.g. substitutions, compared to an IgSF domain contained in an IgSF family member set forth in Table 2.


In some embodiments, the additional IgSF domain is an affinity or non-affinity modified IgSF domain contained in an IgSF family member of a family selected from Signal-Regulatory Protein (SIRP) Family, Triggering Receptor Expressed On Myeloid Cells Like (TREML) Family, Carcinoembryonic Antigen-related Cell Adhesion Molecule (CEACAM) Family, Sialic Acid Binding Ig-Like Lectin (SIGLEC) Family, Butyrophilin Family, B7 family, CD28 family, V-set and Immunoglobulin Domain Containing (VSIG) family, V-set transmembrane Domain (VSTM) family, Major Histocompatibility Complex (MHC) family, Signaling lymphocytic activation molecule (SLAM) family, Leukocyte immunoglobulin-like receptor (LIR), Nectin (Nec) family, Nectin-like (NECL) family, Poliovirus receptor related (PVR) family, Natural cytotoxicity triggering receptor (NCR) family, T cell immunoglobulin and mucin (TIM) family or Killer-cell immunoglobulin-like receptors (KIR) family. In some embodiments, the additional IgSF domains are independently derived from an IgSF protein selected from the group consisting of CD80(B7-1), CD86(B7-2), CD274 (PD-L2, B7-H1), PDCD1LG2(PD-L2, CD273), ICOSLG(B7RP1, CD275, ICOSL, B7-H2), CD276(B7-H3), VTCN1(B7-H4), CD28, CTLA4, PDCD1(PD-1), ICOS, BTLA(CD272), CD4, CD8A(CD8-alpha), CD8B(CD8-beta), LAG3, HAVCR2(TIM-3), CEACAM1, TIGIT, PVR(CD155), PVRL2(CD112), CD226, CD2, CD160, CD200, CD200R1(CD200R), and NC R3 (NKp30).


The first column of Table 2 provides the name and, optionally, the name of some possible synonyms for that particular IgSF member. The second column provides the protein identifier of the UniProtKB database, a publicly available database accessible via the internet at uniprot.org or, in some cases, the GenBank Number. The Universal Protein Resource (UniProt) is a comprehensive resource for protein sequence and annotation data. The UniProt databases include the UniProt Knowledgebase (UniProtKB). UniProt is a collaboration between the European Bioinformatics Institute (EMBL-EBI), the SIB Swiss Institute of Bioinformatics and the Protein Information Resource (PIR) and supported mainly by a grant from the U.S. National Institutes of Health (NIH). GenBank is the NIH genetic sequence database, an annotated collection of all publicly available DNA sequences (Nucleic Acids Research, 2013 January; 41(D1): D36-42). The third column provides the region where the indicated IgSF domain is located. The region is specified as a range where the domain is inclusive of the residues defining the range. Column 3 also indicates the IgSF domain class for the specified IgSF region. Column 4 provides the region where the indicated additional domains are located (signal peptide, S; extracellular domain, E; transmembrane domain, T; cytoplasmic domain, C). It is understood that description of domains can vary depending on the methods used to identify or classify the domain, and may be identified differently from different sources. The description of residues corresponding to a domain in Table 2 is for exemplification only and can be several amino acids (such as one, two, three or four) longer or shorter. Column 5 indicates for some of the listed IgSF members, some of its cognate cell surface binding partners.









TABLE 2







IgSF members according to the present disclosure.














NCBI








Protein


















Accession



IgSF Member Amino Acid Sequence



Number/


Cognate Cell
(SEQ ID NO)














IgSF
UniProtKB
IgSF Region

Surface
Precursor




Member
Protein
& Domain
Other
Binding
(mature




(Synonyms)
Identifier
Class
Domains
Partners
residues)
Mature
ECD





CD80
NP_005182.1
35-135, 35-
S: 1-34,
CD28, CTLA4,
SEQ ID NO: 1
SEQ ID
SEQ ID


(B7-1)
P33681
138, 37-138 or
E: 35-242,
PD-L1
(35-288)
NO: 213
NO: 28




35-141 IgV,
T: 243-263,








145-230 or
C: 264-288








154-232 IgC







CD86
P42081.2
33-131 IgV,
S: 1-23,
CD28, CTLA4
SEQ ID NO: 2
SEQ ID
SEQ ID


(B7-2)

150-225 IgC2
E: 24-247,

(24-329)
NO: 214
NO: 29





T: 248-268,









C: 269-329






CD274
Q9NZQ7.1
24-130 IgV,
S: 1-18,
PD-1, B7-1
SEQ ID NO: 3
SEQ ID
SEQ ID


(PD-L1,

133-225 IgC2
E: 19-238,

(19-290)
NO: 215
NO: 30


B7-H1)


T: 239-259,









C: 260-290






PDCD1LG2
Q9BQ51.2
21-118 IgV,
S: 1-19,
PD-1, RGMb
SEQ ID NO: 4
SEQ ID
SEQ ID


(PD-L2,

122-203 IgC2
E: 20-220,

(20-273)
NO: 216
NO: 31


CD273)


T: 221-241,









C: 242-273






ICOSLG
O75144.2
19-129 IgV,
S: 1-18,
ICOS, CD28,
SEQ ID NO: 5
SEQ ID
SEQ ID


(B7RP1,

141-227 IgC2
E: 19-256,
CTLA4
(19-302)
NO: 217
NO: 32


CD275,


T: 257-277,






ICOSL, B7-


C: 278-302






H2)









CD276
Q5ZPR3.1
29-139 IgV,
S: 1-28,

SEQ ID NO: 6
SEQ ID
SEQ ID


(B7-H3)

145-238 IgC2,
E: 29-466,

(29-534)
NO: 218
NO: 33




243-357 IgV2,
T: 467-487,








363-456, 367-
C: 488-534








453 IgC2







VTCN1
Q7Z7D3.1
35-146 IgV,
S: 1-24,

SEQ ID NO: 7
SEQ ID
SEQ ID


(B7-H4)

153-241 IgV
E: 25-259,

(25-282)
NO: 219
NO: 34





T: 260-280,









C: 281-282






CD28
P10747.1
28-137 IgV
S: 1-18,
B7-1, B7-2,
SEQ ID NO: 8
SEQ ID
SEQ ID





E: 19-152,
B7RP1
(19-220)
NO: 220
NO: 35





T: 153-179,









C: 180-220






CTLA4
P16410.3
39-140 IgV
S: 1-35,
B7-1, B7-2,
SEQ ID NO: 9
SEQ ID
SEQ ID





E: 36-161,
B7RP1
(36-223)
NO: 221
NO: 36





T: 162-182,









C: 183-223






PDCD1
Q15116.3
35-145 IgV
S: 1-20,
PD-L2, PD-L2
SEQ ID NO: 10
SEQ ID
SEQ ID


(PD-1)


E: 21-170,

(21-288)
NO: 222
NO: 37





T: 171-191,









C: 192-288






ICOS
Q9Y6W8.1
30-132 IgV
S: 1-20,
B7RP1
SEQ ID NO: 11
SEQ ID
SEQ ID





E: 21-140,

(21-199)
NO: 223
NO: 38





T: 141-161,









C: 162-199






BTLA
Q7Z6A9.3
31-132 IgV
S: 1-30,
HVEM
SEQ ID NO: 12
SEQ ID
SEQ ID


(CD272)


E: 31-157,

(31-289)
NO: 224
NO: 39





T: 158-178,









C: 179-289






CD4
P01730.1
26-125 IgV,
S: 1-25,
MHC class II
SEQ ID NO: 13
SEQ ID
SEQ ID




126-203 IgC2,
E: 26-396,

(26-458)
NO: 225
NO: 40




204-317 IgC2,
T: 397-418,








317-389, 318-
C: 419-458








374 IgC2







CD8A
P01732.1
22-135 IgV
S: 1-21, E:
MHC class I
SEQ ID NO: 14
SEQ ID
SEQ ID


(CD8-


22-182, T:

(22-235)
NO: 226
NO: 41


alpha)


183-203,









C: 204-235






CD8B
P10966.1
22-132 IgV
S: 1-21,
MHC class I
SEQ ID NO: 15
SEQ ID
SEQ ID


(CD8-beta)


E: 22-170,

(22-210)
NO: 227
NO: 42





T: 171-191,









C: 192-210






LAG3
P18627.5
37-167 IgV,
S: 1-28,
MHC class II
SEQ ID NO: 16
SEQ ID
SEQ ID




168-252 IgC2,
E: 29-450,

(29-525)
NO: 228
NO: 43




265-343 IgC2,
T: 451-471,








349-419 IgC2
C: 472-525






HAVCR2
Q8TDQ0.3
22-124 IgV
S: 1-21,
CEACAM-1,
SEQ ID NO: 17
SEQ ID
SEQ ID


(TIM-3)


E: 22-202,
phosphatidylserine,
(22-301)
NO: 229
NO: 44





T: 203-223,
Galectin-9,








C: 224-301
HMGB1





CEACAM1
P13688.2
35-142 IgV,
S: 1-34,
TIM-3
SEQ ID NO: 18
SEQ ID
SEQ ID




145-232 IgC2,
E: 35-428,

(35-526)
NO: 230
NO: 45




237-317 IgC2,
T: 429-452,








323-413 IgC2
C: 453-526






TIGIT
Q495A1.1
22-124 IgV
S: 1-21,
CD155, CD112
SEQ ID NO: 19
SEQ ID
SEQ ID





E: 22-141,

(22-244)
NO: 231
NO: 46





T: 142-162,









C: 163-244






PVR
P15151.2
24-139 IgV,
S: 1-20,
TIGIT, CD226,
SEQ ID NO: 20
SEQ ID
SEQ ID


(CD155)

145-237 IgC2,
E: 21-343,
CD96,
(21-417)
NO: 232
NO: 47




244-328 IgC2
T: 344-367,
poliovirus








C: 368-417






PVRL2
Q92692.1
32-156 IgV,
S: 1-31,
TIGIT, CD226,
SEQ ID NO: 21
SEQ ID
SEQ ID


(CD112)

162-256 IgC2,
E: 32-360,
CD112R
(32-538)
NO: 233
NO: 48




261-345 IgC2
T: 361-381,









C: 382-538






CD226
Q15762.2
19-126 IgC2,
S: 1-18,
CD155, CD112
SEQ ID NO: 22
SEQ ID
SEQ ID




135-239 IgC2
E: 19-254,

(19-336)
NO: 234
NO: 49





T: 255-275,









C: 276-336






CD2
P06729.2
25-128 IgV,
S: 1-24,
CD58
SEQ ID NO: 23
SEQ ID
SEQ ID




129-209 IgC2
E: 25-209,

(25-351)
NO: 235
NO: 50





T: 210-235,









C: 236-351






CD160
O95971.1
27-122 IgV
N/A
HVEM, MHC
SEQ ID NO: 24
SEQ ID
SEQ ID






family of
(27-159)
NO: 236
NO: 51






proteins





CD200
P41217.4
31-141 IgV,
S: 1-30,
CD200R
SEQ ID NO: 25
SEQ ID
SEQ ID




142-232 IgC2
E: 31-232,

(31-278)
NO: 237
NO: 52





T: 233-259,









C: 260-278






CD200R1
Q8TD46.2
53-139 IgV,
S: 1-28,
CD200
SEQ ID NO: 26
SEQ ID
SEQ ID


(CD200R)

140-228 IgC2
E: 29-243,

(29-325)
NO: 238
NO: 53





T: 244-264,









C: 265-325






NCR3
O14931.1
19-126 IgC-
S: 1-18,
B7-H6
SEQ ID NO: 27
SEQ ID
SEQ ID


(NKp30)

like
E: 19-135,

(19-201)
NO: 239
NO: 54





T: 136-156,









C: 157-201






VSIG8
Q5VU13
22-141 IgV,1
S: 1-21
VISTA
SEQ ID NO: 240
SEQ ID
SEQ ID




146-257
E: 22-263

(22-414)
NO: 241
NO: 242




IgV2
T: 264-284









C: 285-414









In some embodiments, the provided immunomodulatory proteins, in addition to containing a variant PD-L2 polypeptide, also contains at least 2, 3, 4, 5 or 6 additional immunoglobulin superfamily (IgSF) domains, such as an IgD domain of an IgSF family member set forth in Table 2. In some embodiments, the provided immunomodulatory protein contains at least one additional IgSF domain (e.g. second IgSF domain). In some embodiments, the provided immunomodulatory protein contains at least two additional IgSF domains (e.g. second and third IgSF domain). In some embodiments, the provided immunomodulatory protein contains at least three additional IgSF domains (e.g. second, third and fourth). In some embodiments, the provided immunomodulatory protein contains at least four additional IgSF domains (e.g. second, third, fourth and fifth). In some embodiments, the provided immunomodulatory protein contains at least five additional IgSF domains (e.g. second, third, fourth, fifth and sixth). In some embodiments, the provided immunomodulatory protein contains at least six additional IgSF domains (e.g. second, third, fourth, fifth, sixth and seventh). In some embodiments, each of the IgSF domains in the immunomodulatory protein are different. In some embodiments, at least one of the additional IgSF domain is the same as at least one other IgSF domain in the immunomodulatory protein. In some embodiments, each of the IgSF domains is from or derived from a different IgSF family member. In some embodiments, at least two of the IgSF domains is from or derived from the same IgSF family member.


In some embodiments, the additional IgSF domain comprises an IgV domain or an IgC (e.g., IgC2) domain or domains, or a specific binding fragment of the IgV domain or a specific binding fragment of the IgC (e.g., IgC2) domain or domains. In some embodiments, the additional IgSF domain is or comprises a full-length IgV domain. In some embodiments, the additional IgSF domain is or comprises a full-length IgC (e.g., IgC2) domain or domains. In some embodiments, the additional IgSF domain is or comprises a specific binding fragment of the IgV domain. In some embodiments, the additional IgSF domain is or comprises a specific binding fragment of the IgC (e.g., IgC2) domain or domains. In some embodiments, the immunomodulatory protein contains at least two additional IgSF domains from a single (same) IgSF member. For example, in some aspects, the immunomodulatory protein contains an ECD or portion thereof of an IgSF member containing a full-length IgV domain and a full-length IgC (e.g., IgC2) domain or domains or specific binding fragments thereof. In some embodiments, the provided immunomodulatory proteins contains at least one additional IgSF domain (e.g. a second or, in some cases, also a third IgSF domain) in which at least one additional or second IgSF domain is an IgSF domain set forth in a wild-type or unmodified IgSF domain or a specific binding fragment thereof contained in the sequence of amino acids set forth in any of SEQ ID NOS: 1-27 and 240. In some embodiments, the wild-type or unmodified IgSF domain is an IgV domain or an IgC domain, such as an IgC1 or IgC2 domain.


In some embodiments, the provided immunomodulatory proteins, in addition to containing a variant PD-L2 polypeptide, also contains at least one additional affinity-modified IgSF domain (e.g. a second or, in some cases, also a third affinity-modified IgSF domain and so on) in which at least one additional IgSF domain is a vIgD that contains one or more amino acid modifications (e.g. substitution, deletion or mutation) compared to an IgSF domain in a wild-type or unmodified IgSF domain, such as an IgSF domain in an IgSF family member set forth in Table 2. In some embodiments, the additional or second affinity-modified IgSF domain comprises at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to a wild-type or unmodified IgSF domain or a specific binding fragment thereof contained in the sequence of amino acids set forth in any of SEQ ID NOS: 1-27 and 240. In some embodiments, the wild-type or unmodified IgSF domain is an IgV domain or an IgC domain, such as an IgC1 or IgC2 domain. In some embodiments, the additional, e.g., or second or third IgSF domain is an affinity-modified IgV domain and/or IgC domain. In some embodiments, the one or more additional IgSF domain is an affinity-modified IgSF domain that contains an IgV domain and/or an IgC (e.g., IgC2) domain or domains, or a specific binding fragment of the IgV domain and/or a specific binding fragment of the IgC (e.g., IgC2) domain or domains, in which the IgV and/or IgC domain contains the amino acid modification(s) (e.g., substitution(s)). In some embodiments, the one or more additional affinity-modified IgSF domain contains an IgV domain containing the amino acid modification(s) (e.g. substitution(s)). In some embodiments, the one or more additional affinity-modified IgSF domain include IgSF domains present in the ECD or a portion of the ECD of the corresponding unmodified IgSF family member, such as a full-length IgV domain and a full-length IgC (e.g., IgC2) domain or domains, or specific binding fragments thereof, in which one or both of the IgV and IgC contain the amino acid modification(s) (e.g. substitution(s)).


In some embodiments, the immunomodulatory polypeptide comprising a variant PD-L2 can include one or more vIgD of PD-L2 provided herein. In some embodiments, a variant PD-L2 immunomodulatory protein provided herein will comprise exactly 1, 2, 3, 4, 5 or more variant PD-L2 sequences. In some embodiments, at least two of variant PD-L2 sequences are identical variant IgSF domains.


In some embodiments, the provided immunomodulatory polypeptide comprises two or more vIgD sequences of PD-L2. Multiple variant PD-L2 within the polypeptide chain can be identical (i.e., the same species) to each other or be non-identical (i.e., different species) variant PD-L2 sequences. In addition to single polypeptide chain embodiments, in some embodiments two, three, four, or more of the polypeptides of the invention can be covalently or non-covalently attached to each other. Thus, monomeric, dimeric, and higher order (e.g., 3, 4, 5, or more) multimeric proteins are provided herein. For example, in some embodiments exactly two polypeptides of the invention can be covalently or non-covalently attached to each other to form a dimer. In some embodiments, attachment is made via interchain cysteine disulfide bonds. Compositions comprising two or more polypeptides of the invention can be of an identical species or substantially identical species of polypeptide (e.g, a homodimer) or of non-identical species of polypeptides (e.g., a heterodimer). A composition having a plurality of linked polypeptides of the invention can, as noted above, have one or more identical or non-identical variant PD-L2 of the invention in each polypeptide chain. In some specific embodiments, identical or substantially identical species (allowing for 3 or fewer N-terminus or C-terminus amino acid sequence differences) of PD-L2-Fc variant fusion polypeptides will be dimerized to create a homodimer. Alternatively, different species of PD-L2-Fc variant fusion polypeptides can be dimerized to yield a heterodimer.


In some embodiments, the provided immunomodulatory protein contains at least one additional (e.g., second or, in some cases, also a third IgSF domain and so on) IgSF domain that is a vIgD that contains one or more amino acid substitutions compared to an IgSF domain (e.g. IgV) of a wild-type or unmodified IgSF domain other than PD-L2.


In some embodiments, the one or more additional IgSF domain (e.g. second or third IgSF) domain is an IgSF domain (e.g. IgV) of another IgSF family member that itself also binds to an inhibitory receptor. In some aspects, the one or more additional IgSF domain (e.g. second or third IgSF) domain is an affinity-modified IgSF domain that is a variant IgSF domain (vIgD) of an IgSF family member that bind to an inhibitory receptor and that contains or is a vIgD thereof that contains one or more amino acid substitutions in an IgSF domain (e.g. IgV), in which, in some cases, the one or more amino acid modifications result in increased binding to the inhibitory receptor. In some embodiments, the vIgD contains one or more amino acid modifications (e.g. substitutions, deletions or additions) in a wild-type or unmodified IgSF domain (e.g. IgV) of an IgSF family member that binds to an inhibitory receptor. In addition to PD-1, exemplary of such inhibitory receptors are CTLA-4, LAG3, TIGIT, TIM-3, or BTLA. In some embodiments, the one or more additional IgSF domain is from an IgSF family member selected from CD112, CD155, PD-L1, CD80 or CEACAM1. Thus, in some aspects, provided are multi-target checkpoint antagonists that target or block activity of more than one inhibitory receptor. In some embodiments, the immunomodulatory protein in a multi-target checkpoint antagonist that targets or blocks activity of at least two, three, four or more inhibitory receptors.


In some embodiments, there is provided an immunomodulatory protein containing any one of the variant PD-L2 polypeptides and one or more IgSF domain of an inhibitory receptor, such as a wild-type or unmodified inhibitory receptor. In some embodiments, there is provided an immunomodulatory protein containing any one of the variant PD-L2 polypeptides and one or more IgSF domain of CD80, e.g. wild-type or unmodified CD80, such as an IgV domain set forth in SEQ ID NO:1039, 1113, 2039 or an ECD or a portion thereof (containing the IgV and IgC domain or specific binding fragments thereof) set forth in SEQ ID NO:28 or a portion thereof. In some embodiments, there is provided an immunomodulatory protein containing any one of the variant PD-L2 polypeptides and one or more IgSF domain of PD-L1, e.g. wild-type or unmodified PD-L1, such as an IgV domain set forth in SEQ ID NO: 1258 or 1454 or an ECD or a portion thereof (containing the IgV and IgC domain or specific binding fragments thereof) set forth in SEQ ID NO: 30 or 1812 or a portion thereof. In some embodiments, there is provided an immunomodulatory protein containing any one of the variant PD-L2 polypeptides and one or more IgSF domain of CD112, e.g. wild-type or unmodified CD112, such as an IgV domain set forth in SEQ ID NO: 700 or 795 or an ECD or a portion thereof (containing the IgV and IgC domain or specific binding fragments thereof) set forth in SEQ ID NO:48 or a portion thereof. In some embodiments, there is provided an immunomodulatory protein containing any one of the variant PD-L2 polypeptides and one or more IgSF domain of CD155, e.g. wild-type or unmodified CD155, such as an IgV domain set forth in SEQ ID NO:344 or 387 or an ECD or a portion thereof (containing the IgV and IgC domain or specific binding fragments thereof) set forth in SEQ ID NO:47 or a portion thereof.


In some embodiments, there is provided an immunomodulatory protein containing one or more additional IgSF domain (e.g., second or third IgSF) that is a vIgD of an IgSF family member that binds to an inhibitory receptor in which the one or more amino acid modifications in an IgSF domain (e.g. IgV) results in increased binding affinity of the vIgD, or a fusion or immunomodulatory protein containing the vIgD, for its inhibitory receptor cognate binding partner compared to the unmodified IgSF domain, such as binding affinity that is increased more than 1.2-fold, 1.5-fold, 2-fold, 3-fold, 4-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold, 20-fold, 30-fold 40-fold or 50-fold. In some embodiments, the one or more amino acid modifications in an IgSF domain (e.g. IgV) results in increased selectivity of the vIgD, or a fusion or immunomodulatory protein containing the vIgD for its inhibitory receptor compared to the unmodified IgSF domain. In some embodiments, the increased selectivity is a greater ratio of binding of the vIgD for the inhibitory receptor versus another cognate binding partner, such as a cognate binding partner that is not an inhibitory receptor, compared to the ratio of binding of the unmodified IgSF for the inhibitory receptor versus the another cognate binding partner. In some embodiments, the ratio is greater by at least or at least about 1.2-fold, 1.5-fold, 2-fold, 3-fold, 4-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold, 20-fold, 30-fold 40-fold or 50-fold.


In some embodiments, the at least one additional (e.g. second or third) vIgD is an IgSF domain (e.g. IgV) of a variant CD80 polypeptide that contains one or more amino acid modifications (e.g. substitutions, deletions or additions) in the IgSF domain (e.g. IgV) compared to unmodified or wild-type of CD80, which, in some aspects, result in increased, binding to the inhibitory receptor CTLA-4. Exemplary amino acid modifications, such as substitutions, deletions or additions, in an IgSF domain (e.g. IgV or ECD containing IgV and IgC) of a variant CD80 polypeptide are set forth in Table 3. In some embodiments, there is provided an immunomodulatory protein containing any of the provided variant PD-L2 polypeptides and a variant CD80 polypeptide containing an IgV domain including any of the amino acid modifications set forth in Table 3, such as the IgV domain set forth in any of SEQ ID NOS: 1040-1072, 1074-1112, 1114-1146, 1148-1186 or an IgV domain that has at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% to any of SEQ ID NOS: 1040-1072, 1074-1112, 1114-1146, 1148-1186 and contains the one or more amino acid modifications. In some embodiments, there is provided an immunomodulatory protein containing any of the provided variant PD-L2 polypeptides and a variant CD80 polypeptide containing an ECD or a portion thereof containing the IgV and/or IgC domains, in which is contained any of the amino acid modifications set forth in Table 3, such as the ECD set forth in any of SEQ ID NOS: 966-998, 1000-1038 or an ECD that contains at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% to any of SEQ ID NOS: 966-998, 1000-1038 and contains the one or more amino acid modifications.


In some embodiments, the at least one additional (e.g., second or third) vIgD is an IgSF domain (e.g. IgV) of a variant CD112 polypeptide that contains one or more amino acid modifications (e.g., substitutions, deletions or additions) in the IgSF domain (e.g., IgV) compared to unmodified or wild-type CD112, which, in some aspects, result in increased binding to the inhibitory receptor TIGIT. Exemplary amino acid modifications, such as substitutions, deletions or additions, in an IgSF domain (e.g. IgV or ECD containing IgV and IgC) of a variant CD112 polypeptide are set forth in Table 4. In some embodiments, there is provided an immunomodulatory protein containing any of the provided variant PD-L2 polypeptides and a variant CD112 polypeptide containing an IgV domain including any of the amino acid modifications set forth in Table 4, such as the IgV domain set forth in any of SEQ ID NOS: 748-794, 796-842, 884-965, 1479-1526 or an IgV domain that has at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% to any of SEQ ID NOS: 748-794, 796-842, 884-965, 1479-1526, and contains the one more amino acid modifications. In some embodiments, there is provided an immunomodulatory protein containing any of the provided variant PD-L2 polypeptides and a variant CD112 polypeptide containing an ECD or a portion thereof containing the IgV and/or IgC domains, in which is contained any of the amino acid modifications set forth in Table 4, such as the ECD set forth in any of SEQ ID NOS: 701-747, 843-883, 1455-1478 or an ECD that contains at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% to any of SEQ ID NOS: 701-747, 843-883, 1455-1478 and contains the one or more amino acid modifications.


In some embodiments, the at least one additional (e.g., second or third) vIgD is an IgSF domain (e.g. IgV) of a variant CD155 polypeptide that contains one or more amino acid modifications (e.g., substitutions, deletions or additions) in the IgSF domain (e.g., IgV) compared to unmodified or wild-type CD155, which, in some aspects, result in increased binding to the inhibitory receptor TIGIT. Exemplary amino acid modifications, such as substitutions, deletions or additions, in an IgSF domain (e.g. IgV or ECD containing IgV and IgC) of a variant CD155 polypeptide are set forth in Table 5. In some embodiments, there is provided an immunomodulatory protein containing any of the provided variant PD-L2 polypeptides and a variant CD155 polypeptide containing an IgV domain including any of the amino acid modifications set forth in Table 5, such as the IgV domain set forth in any of SEQ ID NOS: 366-386, 388-408, 506-699, 1527-1595, 1597-1598, 1645-1736 or an IgV domain that has at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% to any of SEQ ID NOS: 366-386, 388-408, 506-699, 1527-1595, 1597-1598, 1645-1736 and contains the one more amino acid modifications. In some embodiments, there is provided an immunomodulatory protein containing any of the provided variant PD-L2 polypeptides and a variant CD155 polypeptide containing an ECD or a portion thereof containing the IgV and/or IgC domains, in which is contained any of the amino acid modifications set forth in Table 5, such as the ECD set forth in any of SEQ ID NOS: 1573-1596, 1599-1644 or an ECD that contains at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% to any of SEQ ID NOS: 1573-1596, 1599-1644 and contains the one or more amino acid modifications.


In some embodiments, the at least one additional (e.g., second or third) vIgD is an IgSF domain (e.g. IgV) of a variant PD-L1 polypeptide that contains one or more amino acid modifications (e.g., substitutions, deletions or additions) in the IgSF domain (e.g., IgV or ECD) compared to unmodified or wild-type PD-L1, which, in some aspects, result in increased binding to the inhibitory receptor PD-1. Exemplary amino acid modifications, such as substitutions, deletions or additions, in an IgSF domain (e.g. IgV or ECD containing IgV and IgC) of a variant PD-L1 polypeptide are set forth in Table 8. In some embodiments, there is provided an immunomodulatory protein containing any of the provided variant PD-L2 polypeptides and a variant PD-L1 polypeptide containing an IgV domain including any of the amino acid modifications set forth in Table 8, such as the IgV domain set forth in any of SEQ ID NOS: 1324-1453, 1810-1811, 1992-2021, or an IgV domain that has at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% to any of SEQ ID NOS: 1324-1453, 1810-1811, 1992-2021, and contains the one more amino acid modifications. In some embodiments, there is provided an immunomodulatory protein containing any of the provided variant PD-L2 polypeptides and a variant PD-L1 polypeptide containing an ECD or a portion thereof containing the IgV and/or IgC domains, in which is contained any of the amino acid modifications set forth in Table 8, such as the ECD set forth in any of SEQ ID NOS: 1259-1323, 1743-1809, 1813-1991 or an ECD that contains at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% to any of SEQ ID NOS: 1259-1323, 1743-1809, 1813-1991, and contains the one or more amino acid modifications.


In some embodiments, the one or more additional IgSF domain (e.g. second or third IgSF) domain is an IgSF domain (e.g. IgV) of another IgSF family member that binds or recognizes a tumor antigen. In such embodiments, the IgSF family member serves as a tumor-localizing moiety, thereby bringing the vIgD of PD-L2 in close proximity to immune cells in the tumor microenvironment. In some embodiments, the additional IgSF domain (e.g. second IgSF) domain is an IgSF domain of NKp30, which binds or recognizes B7-H6 expressed on a tumor cell. In some embodiments, the at least one additional (e.g. second) IgSF domain, e.g. NKp30, is an affinity-modified IgSF domain or vIgD that contains one or more amino acid modifications (e.g. substitutions, deletions or additions). In some embodiments, the one or more amino acid modifications increase binding affinity and/or selectivity to B7-H6 compared to unmodified IgSF domain, e.g. NKp30, such as by at least or at least about 1.2-fold, 1.5-fold, 2-fold, 3-fold, 4-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold, 20-fold, 30-fold 40-fold or 50-fold. Exemplary amino acid modifications, such as substitutions, deletions or additions, in an IgSF domain (e.g. IgC-like or full ECD) of a variant NKp30 polypeptide are set forth in Table 6. Among the exemplary polypeptides is an NKp30 variant that contains the mutations L30V/A60V/S64P/S86G with reference to positions in the NKp30 extracellular domain corresponding to positions set forth in SEQ ID NO: 54. In some embodiments, there is provided an immunomodulatory protein containing any of the provided variant PD-L2 polypeptides and a variant NKp30 polypeptide containing an IgC-like domain including any of the amino acid modifications set forth in Table 6, such as the IgC-like domain set forth in any of SEQ ID NOS: 1232-1236 or an IgC-like domain that has at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% to any of SEQ ID NOS: 1232-1236 and contains the one more amino acid modifications. In some embodiments, there is provided an immunomodulatory protein containing any of the provided variant PD-L2 polypeptides and a variant NKp30 polypeptide containing an ECD or a portion thereof containing an IgSF domain or domains, in which is contained any of the amino acid modifications set forth in Table 6, such as the ECD set forth in any of SEQ ID NOS: 1226-1230 or an ECD that contains at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% to any of SEQ ID NOS: 1226-1230 and contains the one or more amino acid modifications.


In some embodiments, the at least one additional (e.g., second or third) vIgD is an IgSF domain (e.g. IgV) of a variant CD86 polypeptide that contains one or more amino acid modifications (e.g., substitutions, deletions or additions) in the IgSF domain (e.g., IgV) compared to unmodified or wild-type CD86, which, in some aspects, result in increased binding to its cognate binding partner. Exemplary amino acid modifications, such as substitutions, deletions or additions, in an IgSF domain (e.g. IgV or ECD containing IgV and IgC) of a variant CD86 polypeptide are set forth in Table 7. Among exemplary polypeptides include CD86 variants that contain the mutations Q35H/H90L/Q102H with reference to positions in the CD86 extracellular domain corresponding to positions set forth in SEQ ID NO: 29. In some embodiments, there is provided an immunomodulatory protein containing any of the provided variant PD-L2 polypeptides and a variant CD86 polypeptide containing an IgV domain including any of the amino acid modifications set forth in Table 7, such as the IgV domain set forth in any of SEQ ID NOS: 1244-1247 or an IgV domain that has at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% to any of SEQ ID NOS: 1244-1247 and contains the one more amino acid modifications. In some embodiments, there is provided an immunomodulatory protein containing any of the provided variant PD-L2 polypeptides and a variant CD86 polypeptide containing an ECD or a portion thereof containing the IgV and/or IgC domains, in which is contained any of the amino acid modifications set forth in Table 7, such as the ECD set forth in any of SEQ ID NOS: 1239-1242 or an ECD that contains at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% to any of SEQ ID NOS: 1239-1242 and contains the one or more amino acid modifications.


Tables 3-8 provide exemplary polypeptides containing one or more affinity-modified IgSF domains that can be used in stack constructs provided herein.









TABLE 3







Exemplary variant CD80 polypeptides










ECD




SEQ ID
IgV SEQ


Mutation(s)
NO
ID NO












Wild-type
28
1039, 2039


L70P
966
1040, 1114


I30F/L70P
967
1041, 1115


Q27H/T41S/A71D
968
1042, 1116


I30T/L70R
969
1043, 1117


T13R/C16R/L70Q/A71D
970
1044, 1118


T57I
971
1045, 1119


M43I/C82R
972
1046, 1120


V22L/M38V/M47T/A71D/L85M
973
1047, 1121


I30V/T57I/L70P/A71D/A91T
974
1048, 1122


V22I/L70M/A71D
975
1049, 1123


N55D/L70P/E77G
976
1050, 1124


T57A/I69T
977
1051, 1125


N55D/K86M
978
1052, 1126


L72P/T79I
979
1053, 1127


L70P/F92S
980
1054, 1128


T79P
981
1055, 1129


E35D/M47I/L65P/D90N
982
1056, 1130


L25S/E35D/M47I/D90N
983
1057, 1131


A71D
985
1059, 1133


E81K/A91S
987
1061, 1135


A12V/M47V/L70M
988
1062, 1136


K34E/T41A/L72V
989
1063, 1137


T41S/A71D/V84A
990
1064, 1138


E35D/A71D
991
1065, 1139


E35D/M47I
992
1066, 1140


K36R/G78A
993
1067, 1141


Q33E/T41A
994
1068, 1142


M47V/N48H
995
1069, 1143


M47L/V68A
996
1070, 1144


S44P/A71D
997
1071, 1145


Q27H/M43I/A71D/R73S
998
1072, 1146


E35D/T57I/L70Q/A71D
1000
1074, 1148


M47I/E88D
1001
1075, 1149


M42I/I61V/A71D
1002
1076, 1150


P51A/A71D
1003
1077, 1151


H18Y/M47I/T57I/A71G
1004
1078, 1152


V20I/M47V/T57I/V84I
1005
1079, 1153


V20I/M47V/A71D
1006
1080, 1154


A71D/L72V/E95K
1007
1081, 1155


V22L/E35G/A71D/L72P
1008
1082, 1156


E35D/A71D
1009
1083, 1157


E35D/I67L/A71D
1010
1084, 1158


Q27H/E35G/A71D/L72P/T79I
1011
1085, 1159


T13R/M42V/M47I/A71D
1012
1086, 1160


E35D
1013
1087, 1161


E35D/M47I/L70M
1014
1088, 1162


E35D/A71D/L72V
1015
1089, 1163


E35D/M43L/L70M
1016
1090, 1164


A26P/E35D/M43I/L85Q/E88D
1017
1091, 1165


E35D/D46V/L85Q
1018
1092, 1166


Q27L/E35D/M47I/T57I/L70Q/E88D
1019
1093, 1167


M47V/I69F/A71D/V83I
1020
1094, 1168


E35D/T57A/A71D/L85Q
1021
1095, 1169


H18Y/A26T/E35D/A71D/L85Q
1022
1096, 1170


E35D/M47L
1023
1097, 1171


E23D/M42V/M43I/I58V/L70R
1024
1098, 1172


V68M/L70M/A71D/E95K
1025
1099, 1173


N55I/T57I/I69F
1026
1100, 1174


E35D/M43I/A71D
1027
1101, 1175


T41S/T57I/L70R
1028
1102, 1176


H18Y/A71D/L72P/E88V
1029
1103, 1177


V20I/A71D
1030
1104, 1178


E23G/A26S/E35D/T62N/A71D/L72V/L85M
1031
1105, 1179


A12T/E24D/E35D/D46V/I61V/L72P/E95V
1032
1106, 1180


V22L/E35D/M43L/A71G/D76H
1033
1107, 1181


E35G/K54E/A71D/L72P
1034
1108, 1182


L70Q/A71D
1035
1109, 1183


A26E/E35D/M47L/L85Q
1036
1110, 1184


D46E/A71D
1037
1111, 1185


Y31H/E35D/T41S/V68L/K93R/R94W
1038
1112, 1186
















TABLE 4







Exemplary variant CD112 polypeptides










ECD




SEQ




ID
IgV SEQ


Mutation(s)
NO
ID NO












Wild-type
48
700, 795


Y33H, A112V, G117D
701
748, 796


V19A, Y33H, S64G, S80G, G98S, N106Y, A112V
702
749, 797


L32P, A112V
703
750, 798


A95V, A112I
704
751, 799


P28S, A112V
705
752, 800


P27A, T38N, V101A, A112V
706
753, 801


S118F
707
754, 802


R12W, H48Y, F54S, S118F
708
755, 803


R12W, Q79R, S118F
709
756, 804


T113S, S118Y
710
757, 805


S118Y
711
758, 806


N106I, S118Y
712
759, 807


N106I, S118F
713
760, 808


A95T, L96P, S118Y
714
761, 809


Y33H, P67S, N106Y, A112V
715
762, 810


N106Y, A112V
716
763, 811


T18S, Y33H, A112V
717
764, 812


P9S, Y33H, N47S, A112V
718
765, 813


P42S, P67H, A112V
719
766, 814


P27L, L32P, P42S, A112V
720
767, 815


G98D, A112V
721
768, 816


Y33H, S35P, N106Y, A112V
722
769, 817


L32P, P42S, T100A, A112V
723
770, 818


P27S, P45S, N106I, A112V
724
771, 819


Y33H, N47K, A112V
725
772, 820


Y33H, N106Y, A112V
726
773, 821


K78R, D84G, A112V, F114S
727
774, 822


Y33H, N47K, F54L, A112V
728
775, 823


Y33H, A112V
729
776, 824


A95V, A112V
730
777, 825


R12W, A112V
731
778, 826


R12W, P27S, A112V
732
779, 827


Y33H, V51M, A112V
733
780, 828


Y33H, A112V, S118T
734
781, 829


Y33H, V101A, A112V, P115S
735
782, 830


H24R, T38N, D43G, A112V
736
783, 831


A112V
737
784, 832


P27A, A112V
738
785, 833


A112V, S118T
739
786, 834


R12W, A112V, M122I
740
787, 835


Q83K, N106Y, A112V
741
788, 836


R12W, P27S, A112V, S118T
742
789, 837


P28S, Y33H, A112V
743
790, 838


P27S, Q90R, A112V
744
791, 839


L15V, P27A, A112V, S118T
745
792, 840


Y33H, N106Y, T108I, A112V
746
793, 841


Y33H, P56L, V75M, V101M, A112V
747
794, 842


N47K, Q79R, S118F
843
884, 925


Q40R, P60T, A112V, S118T
844
885, 926


F114Y, S118F
845
886, 927


Y33H, K78R, S118Y
846
887, 928


R12W, A46T, K66M, Q79R, N106I, T113A, S118F
847
888, 929


Y33H, A112V, S118F
848
889, 930


R12W, Y33H, N106I, S118F
849
890, 931


L15V, Q90R, S118F
850
891, 932


N47K, D84G, N106I, S118Y
851
892, 933


L32P, S118F
852
893, 934


Y33H, Q79R, A112V, S118Y
853
894, 935


T18A, N106I, S118T
854
895, 936


L15V, Y33H, N106Y, A112V, S118F
855
896, 937


V37M, S118F
856
897, 938


N47K, A112V, S118Y
857
898, 939


A46T, A112V
858
899, 940


P28S, Y33H, N106I, S118Y
859
900, 941


P30S, Y33H, N47K, V75M, Q79R, N106I, S118Y
860
901, 942


V19A, N47K, N106Y, K116E, S118Y
861
902, 943


Q79R, T85A, A112V, S118Y
862
903, 944


V101M, N106I, S118Y
863
904, 945


Y33H, Q79R, N106I, A112V, S118T
864
905, 946


Q79R, A112V
865
906, 947


Y33H, A46T, Q79R, N106I, S118F
866
907, 948


A112V, G121S
867
908, 949


Y33H, Q79R, N106I, S118Y
868
909, 950


Y33H, N106I, A112V
869
910, 951


Y33H, A46T, V101M, A112V, S118T
870
911, 952


L32P, L99M, N106I, S118F
871
912, 953


L32P, T108A, S118F
872
913, 954


R12W, Q79R, A112V
873
914, 955


Y33H, N106Y, E110G, A112V
874
915, 956


Y33H, N106I, S118Y
875
916, 957


Q79R, S118F
876
917, 958


Y33H, Q79R, G98D, V101M, A112V
877
918, 959


N47K, T81S, V101M, A112V, S118F
878
919, 960


G82S, S118Y
879
920, 961


Y33H, A112V, S118Y
880
921, 962


Y33H, N47K, Q79R, N106Y, A112V
881
922, 963


Y33H, S118T
882
923, 964


R12W, Y33H, Q79R, V101M, A112V
883
924, 965


Y33H, Q83K, A112V, S118T
1455
1479, 1503


V29M, Y33H, N106I, S118F
1456
1480, 1504


Y33H, A46T, A112V
1457
1481, 1505


Y33H, Q79R, S118F
1458
1482, 1506


Y33H, N47K, F74L, S118F
1459
1483, 1507


R12W, V101M, N106I, S118Y
1460
1484, 1508


A46T, V101A, N106I, S118Y
1461
1485, 1509


N106Y, A112V, S118T
1462
1486, 1510


S76P, T81I, V101M, N106Y, A112V, S118F
1463
1487, 1511


P9R, L21V, P22L, I34M, S69F, F74L, A87V,
1464
1488, 1512


A112V, L125A




Y33H, V101M, A112V
1465
1489, 1513


V29A, L32P, S118F
1466
1490, 1514


Y33H, V101M, N106I, A112V
1467
1491, 1515


R12W, Y33H, N47K, Q79R, S118Y
1468
1492, 1516


Y33H, A46T, A112V, S118T
1469
1493, 1517


Y33H, A112V, F114L, S118T
1470
1494, 1518


Y33H, T38A, A46T, V101M, A112V
1471
1495, 1519


P28S, Y33H, S69P, N106I, A112V, S118Y
1472
1496, 1520


Y33H, P42L, N47K, V101M, A112V
1473
1497, 1521


Y33H, N47K, F74S, Q83K, N106I, F111L, A112V,
1474
1498, 1522


S118T




Y33H, A112V, S118T, V119A
1475
1499, 1523


Y33H, N106I, A112V, S118F
1476
1500, 1524


Y33H, K66M, S118F, W124L
1477
1501, 1525


N106I, A112V
1478
1502, 1526
















TABLE 5







Exemplary variant CD155 polypeptides










ECD




SEQ
IgV SEQ


Mutation(s)
ID NO
ID NO












Wild-type
47
344, 387


P18S, P64S, F91S
345
366, 388


P18S, F91S, L104P
346
367, 389


L44P
347
368, 390


A56V
348
369, 391


P18L, L79V, F91S
349
370, 392


P18S, F91S
350
371, 393


P18T, F91S
351
372, 394


P18T, S42P, F91S
352
373, 395


G7E, P18T, Y30C, F91S
353
374, 396


P18T, F91S, G111D
354
375, 397


P18S, F91P
355
376, 398


P18T, F91S, F108L
356
377, 399


P18T, T45A, F91S
357
378, 400


P18T, F91S, R94H
358
379, 401


P18S, Y30C, F91S
359
380, 402


A81V, L83P
360
381, 403


L88P
361
382, 404


R94H
362
383, 405


A13E, P18S, A56V, F91S
363
384, 406


P18T, F91S, V115A
364
385, 407


P18T, Q60K
365
386, 408


S52M
409
506, 603


T45Q, S52L, L104E, G111R
410
507, 604


S42G
411
508, 605


Q62F
412
509, 606


S52Q
413
510, 607


S42A, L104Q, G111R
414
511, 608


S42A, S52Q, L104Q, G111R
415
512, 609


S52W, L104E
416
513, 610


S42C
417
514, 611


S52W
418
515, 612


S52M, L104Q
419
516, 613


S42L, S52L, Q62F, L104Q
420
517, 614


S42W
421
518, 615


S42Q
422
519, 616


S52L
423
520, 617


S52R
424
521, 618


L104E
425
522, 619


G111R
426
523, 620


S52E
427
524, 621


Q62Y
428
525, 622


T45Q, S52M, L104E
429
526, 623


S42N, L104Q, G111R
430
527, 624


S52M, V57L
431
528, 625


S42N, S52Q, Q62F
432
529, 626


S42A, S52L, L104E, G111R
433
530, 627


S42W, S52Q, V57L, Q62Y
434
531, 628


L104Q
435
532, 629


S42L, S52Q, L104E
436
533, 630


S42C, S52L
437
534, 631


S42W, S52R, Q62Y, L104Q
438
535, 632


T45Q, S52R, L104E
439
536, 633


S52R, Q62F, L104Q, G111R
440
537, 634


T45Q, S52L, V57L, L104E
441
538, 635


S52M, Q62Y
442
539, 636


Q62F, L104E, G111R
443
540, 637


T45Q, S52Q
444
541, 638


S52L, L104E
445
542, 639


S42V, S52E
446
543, 640


T45Q, S52R, G111R
447
544, 641


S42G, S52Q, L104E, G111R
448
545, 642


S42N, S52E, V57L, L104E
449
546, 643


S42C, S52M, Q62F
450
547, 644


S42L
451
548, 645


S42A
452
549, 646


S42G, S52L, Q62F, L104Q
453
550, 647


S42N
454
551, 648


P18T, S65A, S67V, F91S
455
552, 649


P18F, T39A, T45Q, T61R, S65N, S67L, E73G, R78G
456
553, 650


P18T, T45Q, T61R, S65N, S67L
457
554, 651


P18F, S65A, S67V, F91S
458
555, 652


P18F, T45Q, T61R, S65N, S67L, F91S, L104P
459
556, 653


P18S, L79P, L104M
460
557, 654


P18S, L104M
461
558, 655


L79P, L104M
462
559, 656


P18T, T45Q, L79P
463
560, 657


P18T, T45Q, T61R, S65H, S67H
464
561, 658


P18T, A81E
465
562, 659


P18S, D23Y, E37P, S52G, Q62M, G80S, A81P, G99Y, S112N
466
563, 660


A13R, D23Y, E37P, S42P, Q62Y, A81E
467
564, 661


A13R, D23Y, E37P, G99Y, S112N
468
565, 662


A13R, D23Y, E37P, Q62M, A77V, G80S, A81P, G99Y
469
566, 663


P18L, E37S, Q62M, G80S, A81P, G99Y, S112N
470
567, 664


P18S, L104T
471
568, 665


P18S, Q62H, L79Q, F91S
472
569, 666


T45Q, S52K, Q62F, L104Q, G111R
473
570, 667


T45Q, S52Q, Q62Y, L104Q, G111R
474
571, 668


T45Q, S52Q, Q62Y, L104E, G111R
475
572, 669


V57A, T61M, S65W, S67A, E96D, L104T
476
573, 670


P18L, V57T, T61S, S65Y, S67A, L104T
477
574, 671


P18T, T45Q
478
575, 672


P18L, V57A, T61M, S65W, S67A, L104T
479
576, 673


T61M, S65W, S67A, L104T
480
577, 674


P18S, V41A, S42G, T45G, L104N
481
578, 675


P18H, S42G, T451, S52T, G53R, S54H, V57L, H59E, T61S, S65D,
482
579, 676


E68G, L104N




P18S, S42G, T45V, F58L, S67W, L104N
483
580, 677


P18S, T45I, L104N
484
581, 678


P18S, S42G, T45G, L104N, V106A
485
582, 679


P18H, H40R, S42G, T45I, S52T, G53R, S54H, V57L, H59E, T61S,
486
583, 680


S65D, E68G, L104Y, V106L, F108H




E37V, S42G, T45G, L104N
487
584, 681


P18S, T45Q, L79P, L104T
488
585, 682


P18L, Q62R
489
586, 683


A13R, D23Y, E37P, S42L, S52G, Q62Y, A81E
490
587, 684


P18L, H49R, L104T, D116N
491
588, 685


A13R, D23Y, E37P, Q62M, G80S, A81P, L104T
492
589, 686


S65T, L104T
493
590, 687


A13R, D23Y, E37P, S52G, V57A, Q62M, K70E, L104T
494
591, 688


P18L, A47V, Q62Y, E73D, L104T
495
592, 689


H40T, V41M, A47V, S52Q, Q62L, S65T, E73R, D97G, E98S, L104T,
496
593, 690


D116N




P18L, S42P, T45Q, T61G, S65H, S67E, L104T, D116N
497
594, 691


P18S, H40T, V41M, A47V, S52Q, Q62L, S65T, E73R, L104M,
498
595, 692


V106A




H40T, V41M, A47V, S52Q, Q62L, S65T, E68G, E73R, D97G,
499
596, 693


E98S, L104T




T45Q, S52E, L104E
500
597, 694


T45Q, S52E, Q62F, L104E
501
598, 695


P18F, T26M, L44V, Q62K, L79P, F91S, L104M, G111D
502
599, 696


P18S, T45S, T61K, S65W, S67A, F91S, G111R
503
600, 697


P18S, L79P, L104M, T107M
504
601, 698


P18S, S65W, S67A, M90V, V95A, L104Q, G111R
505
602, 699


P18S, A47G, L79P, F91S, L104M, T107A, R113W
1573
1527, 1550


P18T, D23G, S24A, N35D, H49L, L79P, F91S, L104M, G111R
1574
1528, 1551


V9L, P18S, Q60R, V75L, L79P, R89K, F91S, L104E, G111R
1575
1529, 1552


P18S, H49R, E73D, L79P, N85D, F91S, V95A, L104M, G111R
1576
1530, 1553


V11A, P18S, L79P, F91S, L104M, G111R
1577
1531, 1554


V11A, P18S, S54R, Q60P, Q62K, L79P, N85D, F91S, T107M
1578
1532, 1555


P18T, S52P, S65A, S67V, L79P, F91S, L104M, G111R
1579
1533, 1556


P18T, M36T, L79P, F91S, G111R
1580
1534, 1557


D8G, P18S, M36I, V38A, H49Q, A76E, F91S, L104M, T107A,
1581
1535, 1558


R113W




P18S, S52P, S65A, S67V, L79P, F91S, L104M, T107S, R113W
1582
1536, 1559


T15I, P18T, L79P, F91S, L104M, G111R
1583
1537, 1560


P18F, T26M, L44V, Q62K, L79P, E82D, F91S, L104M, G111D
1584
1538, 1561


P18T, E37G, G53R, Q62K, L79P, F91S, E98D, L104M, T107M
1585
1539, 1562


P18L, K70E, L79P, F91S, V95A, G111R
1586
1540, 1563


V9I, Q12K, P18F, S65A, S67V, L79P, L104T, G111R, S112I
1587
1541, 1564


P18F, S65A, S67V, F91S, L104M, G111R
1588
1542, 1565


V9I, V10I, P18S, F20S, T45A, L79P, F91S, L104M, F108Y, G111R,
1589
1543, 1566


S112V




V9L, P18L, L79P, M90I, F91S, T102S, L104M, G111R
1590
1544, 1567


P18C, T26M, L44V, M55I, Q62K, L79P, F91S, L104M, T107M
1591
1545, 1568


V9I, P18T, D23G, L79P, F91S, G111R
1592
1546, 1569


P18F, L79P, M90L, F91S, V95A, L104M, G111R
1593
1547, 1570


P18T, M36T, S65A, S67E, L79Q, A81T, F91S, G111R
1594
1548, 1571


V9L, P18T, Q62R, L79P, F91S, L104M, G111R
1595
1549, 1572


P18S, S65W, S67A, L104Q, G111R
1596
1597, 1598


P18T, G19D, M36T, S54N, L79P, L83Q, F91S, T107M, F108Y
1599
1645, 1691


V9L, P18L, M55V, S69L, L79P, A81E, F91S, T107M
1600
1646, 1692


P18F, H40Q, T61K, Q62K, L79P, F91S, L104M, T107V
1601
1647, 1693


P18S, Q32R, Q62K, R78G, L79P, F91S, T107A, R113W
1602
1648, 1694


Q12H, P18T, L21S, G22S, V57A, Q62R, L79P, F91S, T107M
1603
1649, 1695


V9I, P18S, S24P, H49Q, F58Y, Q60R, Q62K, L79P, F91S, T107M
1604
1650, 1696


P18T, W46C, H49R, S65A, S67V, A76T, L79P, S87T, L104M
1605
1651, 1697


P18S, S42T, E51G, L79P, F91S, G92W, T107M
1606
1652, 1698


V10F, T15S, P18L, R48Q, L79P, F91S, T107M, V115M
1607
1653, 1699


P18S, L21M, Y30F, N35D, R84W, F91S, T107M, D116G
1608
1654, 1700


P18F, E51V, S54G, Q60R, L79Q, E82G, S87T, M90I, F91S, G92R,
1609
1655, 1701


T107M




Q16H, P18F, F91S, T107M
1610
1656, 1702


P18T, D23G, Q60R, S67L, L79P, F91S, T107M, V115A
1611
1657, 1703


D8G, V9I, V11A, P18T, T26M, S52P, L79P, F91S, G92A, T107L,
1612
1658, 1704


V115A




V9I, P18F, A47E, G50S, E68G, L79P, F91S, T107M
1613
1659, 1705


P18S, M55I, Q62K, S69P, L79P, F91S, T107M
1614
1660, 1706


P18T, T39S, S52P, S54R, L79P, F91S, T107M
1615
1661, 1707


P18S, D23N, L79P, F91S, T107M, S114N
1616
1662, 1708


P18S, P34S, E51V, L79P, F91S, G111R
1617
1663, 1709


P18S, H59N, V75A, L79P, A81T, F91S, L104M, T107M
1618
1664, 1710


P18S, W46R, E68D, L79P, F91S, T107M, R113G
1619
1665, 1711


V9L, P18F, T45A, S65A, S67V, R78K, L79V, F91S, T107M, S114T
1620
1666, 1712


P18T, M55L, T61R, L79P, F91S, V106I, T107M
1621
1667, 1713


T15I, P18S, V33M, N35F, T39S, M55L, R78S, L79P, F91S, T107M
1622
1668, 1714


P18S, Q62K, K70E, L79P, F91S, G92E, R113W
1623
1669, 1715


P18F, F20I, T26M, A47V, E51K, L79P, F91S
1624
1670, 1716


P18T, D23A, Q60H, L79P, M90V, F91S, T107M
1625
1671, 1717


P18S, D23G, C29R, N35D, E37G, M55I, Q62K, S65A, S67G, R78G,
1626
1672, 1718


L79P, F91S, L104M, T107M, Q110R




A13E, P18S, M36R, Q62K, S67T, L79P, N85D, F91S, T107M
1627
1673, 1719


V9I, P18T, H49R, L79P, N85D, F91S, L104T, T107M
1628
1674, 1720


V9A, P18F, T61S, Q62L, L79P, F91S, G111R
1629
1675, 1721


D8E, P18T, T61A, L79P, F91S, T107M
1630
1676, 1722


P18S, V41A, H49R, S54C, L79S, N85Y, L88P, F91S, L104M,
1631
1677, 1723


T107M




V11E, P18H, F20Y, V25E, N35S, H49R, L79P, F91S, T107M,
1632
1678, 1724


G111R




V11A, P18F, D23A, L79P, G80D, V95A, T107M
1633
1679, 1725


P18S, K70R, L79P, F91S, G111R
1634
1680, 1726


V9L, V11M, P18S, N35S, S54G, Q62K, L79P, L104M, T107M,
1635
1681, 1727


V9L, P18Y, V25A, V38G, M55V, A77T, L79P, M90I, F91S, L104M
1636
1682, 1728


V10G, P18T, L72Q, L79P, F91S, T107M
1637
1683, 1729


P18S, H59R, A76G, R78S, L79P
1638
1684, 1730


V9A, P18S, M36T, S65G, L79P, F91S, L104T, G111R, S112I
1639
1685, 1731


P18T, S52A, V57A, Q60R, Q62K, S65C, L79P, F91T, N100Y,
1640
1686, 1732


T107M




V11A, P18F, N35D, A47E, Q62K, L79P, F91S, G99D, T107M,
1641
1687, 1733


S114N




V11A, P18T, N35S, L79P, S87T, F91S
1642
1688, 1734


V9D, V11M, Q12L, P18S, E37V, M55I, Q60R, K70Q, L79P, F91S,
1643
1689, 1735


L104M, T107M




T15S, P18S, Y30H, Q32L, Q62R, L79P, F91S, T107M
1644
1690, 1736
















TABLE 6







Exemplary variant NKp30 polypeptides











IgC-like



ECD
domain



SEQ
SEQ



ID
ID


Mutation(s)
NO
NO





Wild-type
 54
 1231,




1238


L30V/A60V/S64P/S86G
1226
1232


L30V
1227
1233


A60V
1228
1234


S64P
1229
1235


S86G
1230
1236
















TABLE 7







Exemplary variant CD86 polypeptides










ECD
IgV



SEQ ID
SEQ ID


Mutation(s)
NO
NO












Wild-type
29
1243


Q35H/H9OL/Q102H
1239
1244


Q35H
1240
1245


H90L
1241
1246


Q102H
1242
1247
















TABLE 8







Exemplary variant PD-Ll polypeptides










ECD
IgV



SEQ
SEQ



ID
ID


Mutation(s)
NO
NO





Wild-type
 30, 1812
1258, 1454


K28N/M41V/N45T/H51N/K57E
1259, 1743
1324, 1389


I20L/I36T/N45D/I47T
1260, 1744
1325, 1390


I20L/M41K/K44E
1261, 1745
1326, 1391


P6S/N45T/N78I/I83T
1262, 1746
1327, 1392


N78I
1263, 1747
1328, 1393


M41K/N78I
1264, 1748
1329, 1394


N45T/N78I
1265, 1749
1330, 1395


I20L/N45T
1266, 1750
1331, 1396


N45T
1267, 1751
1332, 1397


M41K
1268, 1752
1333, 1398


I20L/I36T/N45D
1269, 1753
1334, 1399


N17D/N45T/V50A/D72G
1270, 1754
1335, 1400


I20L/F49S
1271, 1755
1336, 1401


N45T/V50A
1272, 1756
1337, 1402


I20L/N45T/N78I
1273, 1757
1338, 1403


I20L/N45T/V50A
1274, 1758
1339, 1404


M41V/N45T
1275, 1759
1340, 1405


M41K/N45T
1276, 1760
1341, 1406


A33D/S75P/D85E
1277, 1761
1342, 1407


M181/M41K/D43G/H51R/N781
1278, 1762
1343, 1408


V11E/I20L/I36T/N45D/H60R/S75P
1279, 1763
1344, 1409


A33D/V50A
1280, 1764
1345, 1410


S16G/A33D/K71E/S75P
1281, 1765
1346, 1411


E27G/N45T/M97I
1282, 1766
1347, 1412


E27G/N45T/K57R
1283, 1767
1348, 1413


A33D/E53V
1284, 1768
1349, 1414


D43G/N45D/V58A
1285, 1769
1350, 1415


E40G/D43V/N45T/V50A
1286, 1770
1351, 1416


Y14S/K28E/N45T
1287, 1771
1352, 1417


A33D/N78S
1288, 1772
1353, 1418


A33D/N78I
1289, 1773
1354, 1419


A33D/N45T
1290, 1774
1355, 1420


A33D/N45T/N78I
1291, 1775
1356, 1421


E27G/N45T/V50A
1292, 1776
1357, 1422


N45T/V50A/N78S
1293, 1777
1358, 1423


I20L/N45T/V110M
1294, 1778
1359, 1424


I20L/I36T/N45T/V50A
1295, 1779
1360, 1425


N45T/L74P/S75P
1296, 1780
1361, 1426


N45T/S75P
1297, 1781
1362, 1427


S75P/K106R
1298, 1782
1363, 1428


S75P
1299, 1783
1364, 1429


A33D/S75P
1300, 1784
1365, 1430


A33D/S75P/D104G
1301, 1785
1366, 1431


A33D/S75P
1302, 1786
1367, 1432


I20L/E27G/N45T/V50A
1303, 1787
1368, 1433


I20L/E27G/D43G/N45D/V58A/N78I
1304, 1788
1369, 1434


I20L/D43G/N45D/V58A/N78I
1305, 1789
1370, 1435


I20L/A33D/D43G/N45D/V58A/N78I
1306, 1790
1371, 1436


I20L/D43G/N45D/N78I
1307, 1791
1372, 1437


E27G/N45T/V50A/N78I
1308, 1792
1373, 1438


N45T/V50A/N78I
1309, 1793
1374, 1439


V11A/I20L/E27G/D43G/N45D/
1310, 1794
1375, 1440


H51Y/S99G




I20L/E27G/D43G/N45T/V50A
1311, 1795
1376, 1441


I20L/K28E/D43G/N45D/V58A/Q89R
1312, 1796
1377, 1442


I20L/I36T/N45D
1313, 1797
1378, 1443


I20L/K28E/D43G/N45D/E53G/
1314, 1798
1379, 1444


V58A/N78I




A33D/D43G/N45D/V58A/S75P
1315, 1799
1380, 1445


K23R/D43G/N45D
1316, 1800
1381, 1446


I20L/D43G/N45D/V58A/N78I/
1317, 1801
1382, 1447


D90G/G101D




D43G/N45D/L56Q/V58A/
1318, 1802
1383, 1448


G101G-ins(G101GG)




I20L/K23E/D43G/N45D/V58A/N78I
1319, 1803
1384, 1449


I20L/K23E/D43G/N45D/V50A/N78I
1320, 1804
1385, 1450


T19I/E27G/N45I/V50A/N78I/M97K
1321, 1805
1386, 1451


I20L/M41K/D43G/N45D
1322, 1806
1387, 1452


K23R/N45T/N78I
1323, 1807
1388, 1453


I20L/K28E/D43G/N45D/V58A/
1808, 1809
1810, 1811


Q89R/G101G-ins (G101GG)




K57R/S99G
1813, 1903
1992, 2007


K57R/S99G/F189L
1814, 1904



M18V/M97L/F193S/R195G/
1815, 1905



E200K/H202Q




I36S/M41K/M97L/K144Q/R195G/
1816, 1906



E200K/H202Q/L206F




C22R/Q65L/L124S/K144Q/R195G/
1817



E200N/H202Q/T221L




M18V/I98L/L124S/P198T/L206F
1818, 1907



S99G/N117S/I148V/K171R/R180S
1819, 1908



I36T/M97L/A103V/Q155H
1820, 1909



K28I/S99G
1821, 1910
1993, 2008


R195S
1822, 1911



A79T/S99G/T185A/R195G/E200K/
1823, 1912



H202Q/L206F




K57R/S99G/L124S/K144Q
1824, 1913



K57R/S99G/R195G
1825, 1914



D55V/M97L/S99G
1826, 1915
1994, 2009


E27G/I36T/D55N/M97L/K111E
1827, 1916
1995, 2010


E54G/M97L/S99G
1828, 1917
1996, 2011


G15A/I36T/M97L/K111E/H202Q
1829, 1918



G15A/I36T/V129D
1830, 1919



G15A/I36T/V129D/R195G
1831, 1920



G15A/V129D
1832, 1921



I36S/M97L
1833, 1922
1997, 2012


136T/D55N/M97L/K111E/A204T
1834, 1923



136T/D55N/M97L/K111E/V129A/F173L
1835, 1924



136T/D55S/M97L/K111E/I148V/R180S
1836, 1925



136T/G52R/M97L/V112A/
1837, 1926



K144E/V175A/P198T




136T/I46V/D55G/M97L/K106E/
1838, 1927



K144E/T185A/R195G




I36T/I83T/M97L/K144E/P198T
1839, 1928



I36T/M97L/K111E
1840, 1929
1998, 2013


I36T/M97L/K144E/P198T
1841, 1930



I36T/M97L/Q155H/F193S/N201Y
1842, 1931



I36T/M97L/V129D
1843, 1932



L35P/I36S/M97L/K111E
1844, 1933
1999, 2014


M18I/I36T/E53G/M97L/K144E/
1845, 1934



E199G/V207A




M18T/I36T/D55N/M97L/K111E
1846, 1935
2000, 2015


M18V/M97L/T176N/R195G
1847, 1936



M97L/S99G
1848, 1937
2001, 2016


N17D/M97L/S99G
1849, 1938
2002, 2017


S99G/T185A/R195G/P198T
1850, 1939



V129D/H202Q
1851, 1940



V129D/P198T
1852, 1941



V129D/T150A
1853, 1942



V93E/V129D
1854, 1943



Y10F/M18V/S99G/Q138R/T203A
1855, 1944



N45D
1856, 1945
2003, 2018


K160M/R195G
1857, 1946



N45D/K144E
1858, 1947



N45D/P198S
1859, 1948



N45D/P198T
1860, 1949



N45D/R195G
1861, 1950



N45D/R195S
1862, 1951



N45D/S131F
1863, 1952



N45D/V58D
1864, 1953
2004, 2019


V129D/R195S
1865, 1954



I98T/F173Y/L196S
1866, 1955



N45D/E134G/L213P
1867, 1956



N45D/F173I/S177C
1868, 1957



N45D/I148V/R195G
1869, 1958



N45D/K111T/R195G
1870, 1959



N45D/N113Y/R195S
1871, 1960



N45D/N165Y/E170G
1872, 1961



N45D/Q89R/I98V
1873, 1962
2005, 2020


N45D/S131F/P198S
1874, 1963



N45D/S75P/P198S
1875, 1964



N45D/V50A/R195T
1876, 1965



E27D/N45D/T183A/I188V
1877, 1966



F173Y/T183I/L196S/T203A
1878, 1967



K23N/N45D/S75P/N120S
1879, 1968



N45D/G102D/R194W/R195G
1880, 1969



N45D/G52V/Q121L/P198S
1881, 1970



N45D/I148V/R195G/N201D
1882, 1971



N45D/K111T/T183A/I188V
1883, 1972



N45D/Q89R/F189S/P198S
1884, 1973



N45D/S99G/C137R/V207A
1885, 1974



N45D/T163I/K167R/R195G
1886, 1975



N45D/T183A/T192S/R194G
1887, 1976



N45D/V50A/I119T/K144E
1888, 1977



T19A/N45D/K144E/R195G
1889, 1978



V11E/N45D/T130A/P198T
1890, 1979



V26A/N45D/T163I/T185A
1891, 1980



K23N/N45D/L124S/K167T/R195G
1892, 1981



K23N/N45D/Q73R/T163I
1893, 1982



K28E/N45D/W149R/S158G/P198T
1894, 1983



K28R/N45D/K57E/I98V/R195S
1895, 1984



K28R/N45D/V129D/T163N/R195T
1896, 1985



M41K/D43G/N45D/R64S/R195G
1897, 1986



M41K/D43G/N45D/R64S/S99G
1898, 1987
2006, 2021


N45D/R68L/F173L/D197G/P198S
1899, 1988



N45D/V50A/I148V/R195G/N201D
1900, 1989



M41K/D43G/K44E/N45D/
1901, 1990



R195G/N201D




N45D/V50A/L124S/K144E/
1902, 1991



L179P/R195G









The number of such non-affinity modified or affinity modified IgSF domains present in a “stacked” immunomodulatory protein construct (whether non-wild type combinations or non-wild type arrangements) is at least 2, 3, 4, or 5 and in some embodiments exactly 2, 3, 4, or 5 IgSF domains (whereby determination of the number of affinity modified IgSF domains disregards any non-specific binding fractional sequences thereof and/or substantially immunologically inactive fractional sequences thereof).


In some embodiments of a stacked immunomodulatory protein provided herein, the number of IgSF domains is at least 2 wherein the number of affinity modified and the number of non-affinity modified IgSF domains is each independently at least: 0, 1, 2, 3, 4, 5, or 6. Thus, the number of affinity modified IgSF domains and the number of non-affinity modified IgSF domains, respectively, (affinity modified IgSF domain: non-affinity modified IgSF domain), can be exactly or at least: 2:0 (affinity modified: wild-type), 0:2, 2:1, 1:2, 2:2, 2:3, 3:2, 2:4, 4:2, 1:1, 1:3, 3:1, 1:4, 4:1, 1:5, or 5:1.


In some embodiments of a stacked immunomodulatory protein, at least two of the non-affinity modified and/or affinity modified IgSF domains are identical IgSF domains.


In some embodiments, a stacked immunomodulatory protein provided herein comprises at least two affinity modified and/or non-affinity modified IgSF domains from a single IgSF member but in a non-wild-type arrangement (alternatively, “permutation”). One illustrative example of a non-wild type arrangement or permutation is an immunomodulatory protein comprising a non-wild-type order of affinity modified and/or non-affinity modified IgSF domain sequences relative to those found in the wild-type PD-L2 whose IgSF domain sequences served as the source of the variant IgSF domains as provided herein. Thus, in one example, the immunomodulatory protein can comprise an IgV proximal and an IgC distal to the transmembrane domain albeit in a non-affinity modified and/or affinity modified form. The presence, in an immunomodulatory protein provided herein, of both non-wild-type combinations and non-wild-type arrangements of non-affinity modified and/or affinity modified IgSF domain is also within the scope of the provided subject matter.


In some embodiments of a stacked immunomodulatory protein, the non-affinity modified and/or affinity modified IgSF domains are non-identical (i.e., different) IgSF domains. Non-identical affinity modified IgSF domains specifically bind, under specific binding conditions, different cognate binding partners and are “non-identical” irrespective of whether or not the wild-type or unmodified IgSF domains from which they are engineered was the same. Thus, for example, a non-wild-type combination of at least two non-identical IgSF domains in an immunomodulatory protein can comprise at least one IgSF domain sequence whose origin is from and unique to one PD-L2, and at least one of a second IgSF domain sequence whose origin is from and unique to another IgSF family member that is not PD-L2, wherein the IgSF domains of the immunomodulatory protein are in non-affinity modified and/or affinity modified form. However, in alternative embodiments, the two non-identical IgSF domains originate from the same IgSF domain sequence but at least one is affinity modified such that they specifically bind to different cognate binding partners.


A plurality of non-affinity modified and/or affinity modified IgSF domains in a stacked immunomodulatory protein polypeptide chain need not be covalently linked directly to one another. In some embodiments, an intervening span of one or more amino acid residues indirectly covalently bonds the non-affinity modified and/or affinity modified IgSF domains to each other. The linkage can be via the N-terminal to C-terminal residues.


In some embodiments, the two or more IgSF domain, including a vIgD of PD-L2 and one or more additional IgSF domain (e.g. second or third variant IgSF domain) from another IgSF family member, are covalently or non-covalently linked. In some embodiments, the two or more IgSF domains are linked directly or indirectly, such as via a linker. In some embodiments, an intervening span of one or more amino acid residues indirectly covalently bonds IgSF domains to each other. The linkage can be via the N-terminal to C-terminal residues. In some embodiments, the linkage can be made via side chains of amino acid residues that are not located at the N-terminus or C-terminus of the IgSF domain(s). Thus, linkages can be made via terminal or internal amino acid residues or combinations thereof.


In some embodiments, the immunomodulatory protein contains at least two IgSF domains, each linked directly or indirectly via a linker. In some embodiments, the immunomodulatory protein contains at least three immunomodulatory proteins, each linked directly or indirectly via a linker. Various configurations are shown in FIGS. 5A and 5B.


In some embodiments, one or more “peptide linkers” link the vIgD of PD-L2 and one or more additional IgSF domain (e.g. second or third variant IgSF domain). In some embodiments, a peptide linker can be a single amino acid residue or greater in length. In some embodiments, the peptide linker has at least one amino acid residue but is no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid residues in length. In some embodiments, the linker is a flexible linker. In some embodiments, the linker is (in one-letter amino acid code): GGGGS (“4GS”) or multimers of the 4GS linker, such as repeats of 2, 3, 4, or 5 4GS linkers. In some embodiments, the peptide linker is (GGGGS)2(SEQ ID NO:264) or (GGGGS)3(SEQ ID NO:263). In some embodiments, the linker also can include a series of alanine residues alone or in addition to another peptide linker (such as a 4GS linker or multimer thereof). In some embodiments, the number of alanine residues in each series is: 2, 3, 4, 5, or 6 alanines. In some embodiments, the linker also can include a series of alanine residues alone or in addition to another peptide linker (such as a 4GS linker or multimer thereof). In some embodiments, the number of alanine residues in each series is: 2, 3, 4, 5, or 6 alanines. In some embodiments, the linker is a rigid linker. For example, the linker is an α-helical linker. In some embodiments, the linker is (in one-letter amino acid code): EAAAK or multimers of the EAAAK linker, such as repeats of 2, 3, 4, or 5 EAAAK linkers, such as set forth in SEQ ID NO: 2030 (1×EAAAK), SEQ ID NO: 2031 (3×EAAAK) or SEQ ID NO: 2032 (5×EAAAK). In some embodiments, the linker can further include amino acids introduced by cloning and/or from a restriction site, for example the linker can include the amino acids GS (in one-letter amino acid code) as introduced by use of the restriction site BAMHI. For example, in some embodiments, the linker (in one-letter amino acid code) is GSGGGGS (SEQ ID NO:1741), GS(G4S)3 (SEQ ID NO: 2040), or GS(G4S)5 (SEQ ID NO: 2041). In some examples, the linker is a 2×GGGGS followed by three alanines (GGGGSGGGGSAAA; SEQ ID NO: 265). In some cases, various combinations of peptide linkers are used.


In some embodiments, the non-affinity modified and/or affinity modified IgSF domains are linked by “wild-type peptide linkers” inserted at the N-terminus and/or C-terminus of a non-affinity modified and/or affinity modified IgSF domains. These linkers are also called leading sequences (N-terminal to non-affinity modified or affinity modified IgSF domain) or trailing sequences (C-terminal to non-affinity modified or affinity modified IgSF domain), and sequences that exist in the wild-type protein that span immediately outside the structural prediction of the Ig fold of the IgSF. In some embodiments, the “wild-type linker” is an amino acid sequence that exists after the signal sequence, but before in the IgSF domain, such as the defined IgV domain, in the amino acid sequence of the wild-type protein. In some embodiments, the “wild-type” linker is an amino acid sequence that exists immediately after the IgSF domain, such as immediately after the defined IgV domain but before the IgC domain, in the amino acid sequence of the wild-type protein. These linker sequences can contribute to the proper folding and function of the neighboring IgSF domain(s). In some embodiments, there is present a leading peptide linker inserted at the N-terminus of the first IgSF domain and/or a trailing sequence inserted at the C-terminus of the first non-affinity modified and/or affinity modified IgSF domain. In some embodiments, there is present a second leading peptide linker inserted at the N-terminus of the second IgSF domain and/or a second trailing sequence inserted at the C-terminus of the second non-affinity modified and/or affinity modified IgSF domain. When the first and second non-affinity modified and/or affinity modified IgSF domains are derived from the same parental protein and are connected in the same orientation, wild-type peptide linkers between the first and second non-affinity modified and/or affinity modified IgSF domains are not duplicated. For example, when the first trailing wild-type peptide linker and the second leading wild-type peptide linker are the same, the Type II immunomodulatory protein does not comprise either the first trailing wild-type peptide linker or the second leading wild-type peptide linker.


In some embodiments, the Type II immunomodulatory protein comprises a first leading wild-type peptide linker inserted at the N-terminus of the first non-affinity modified and/or affinity modified IgSF domain, wherein the first leading wild-type peptide linker comprises at least 5 (such as at least about any of 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or more) consecutive amino acids from the intervening sequence in the wild-type protein from which the first non-affinity modified and/or affinity modified IgSF domain is derived between the parental IgSF domain and the immediately preceding domain (such as a signal peptide or an IgSF domain). In some embodiments, the first leading wild-type peptide linker comprises the entire intervening sequence in the wild-type protein from which the first non-affinity modified and/or affinity modified IgSF domain is derived between the parental IgSF domain and the immediately preceding domain (such as a signal peptide or an IgSF domain).


In some embodiments, the Type II immunomodulatory protein further comprises a first trailing wild-type peptide linker inserted at the C-terminus of the first non-affinity modified and/or affinity modified IgSF domain, wherein the first trailing wild-type peptide linker comprises at least 5 (such as at least about any of 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or more) consecutive amino acids from the intervening sequence in the wild-type protein from which the first non-affinity modified and/or affinity modified IgSF domain is derived between the parental IgSF domain and the immediately following domain (such as an IgSF domain or a transmembrane domain). In some embodiments, the first trailing wild-type peptide linker comprises the entire intervening sequence in the wild-type protein from which the first non-affinity modified and/or affinity modified IgSF domain is derived between the parental IgSF domain and the immediately following domain (such as an IgSF domain or a transmembrane domain).


In some embodiments, the Type II immunomodulatory protein further comprises a second leading wild-type peptide linker inserted at the N-terminus of the second non-affinity modified and/or affinity modified IgSF domain, wherein the second leading wild-type peptide linker comprises at least 5 (such as at least about any of 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or more) consecutive amino acids from the intervening sequence in the wild-type protein from which the second non-affinity modified and/or affinity modified IgSF domain is derived between the parental IgSF domain and the immediately preceding domain (such as a signal peptide or an IgSF domain). In some embodiments, the second leading wild-type peptide linker comprises the entire intervening sequence in the wild-type protein from which the second non-affinity modified and/or affinity modified IgSF domain is derived between the parental IgSF domain and the immediately preceding domain (such as a signal peptide or an IgSF domain).


In some embodiments, the Type II immunomodulatory protein further comprises a second trailing wild-type peptide linker inserted at the C-terminus of the second non-affinity modified and/or affinity modified IgSF domain, wherein the second trailing wild-type peptide linker comprises at least 5 (such as at least about any of 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or more) consecutive amino acids from the intervening sequence in the wild-type protein from which the second non-affinity modified and/or affinity modified IgSF domain is derived between the parental IgSF domain and the immediately following domain (such as an IgSF domain or a transmembrane domain). In some embodiments, the second trailing wild-type peptide linker comprises the entire intervening sequence in the wild-type protein from which the second non-affinity modified and/or affinity modified IgSF domain is derived between the parental IgSF domain and the immediately following domain (such as an IgSF domain or a transmembrane domain).


In some embodiments, the two or more IgSF domain, including a vIgD of PD-L2 and one or more additional IgSF domain (e.g. second and/or third variant IgSF domain) from another IgSF family member, are linked or attached to a multimerization domain, such as to an Fc to form an Fc fusion, which, upon expression in a cell can, in some aspects, produce a dimeric multi-domain stack immunomodulatory protein. Thus, also provided are dimeric multi-domain immunomodulatory proteins.


In some embodiments, the variant PD-L2 polypeptide and one or more additional IgSF domain are independently linked, directly or indirectly, to the N- or C-terminus of a multimerization domain, such as an Fc region. In some embodiments, the variant PD-L2 polypeptide and at least one of the one or more additional IgSF domain are linked, directly or indirectly, and one of the variant PD-L2 and one of the one or more additional IgSF domain is also linked, directly or indirectly, to the N- or C-terminus of the multimerization domain, such as an Fc region. In some embodiments, the N- or C-terminus of the multimerization domain, such as an Fc region, is linked to the variant PD-L2 polypeptide or the one or more additional IgSF domain and the other of the N- or C-terminus of the Fc region is linked to the other of the PD-L2 variant or another of the one or more additional IgSF domain. In some embodiments, linkage to the multimerization domain, such as to an Fc, is via a peptide linker, e.g. a peptide linker, such as described above. In some embodiments, linkage between the variant PD-L2 and the one or more additional second IgSF domain is via a peptide linker, e.g. a peptide linker, such as described above. In some embodiments, the vIgD of PD-L2, the one or more additional IgSF domains, and the multimerization domain, such as an Fc domain, can be linked together in any of numerous configurations as depicted in FIGS. 5A and 5B. Exemplary configurations are described in the Examples.


In some embodiments, the stacked immunomodulatory protein is a dimer formed by two immunomodulatory Fc fusion polypeptides. Also provided are nucleic acid molecules encoding any of the stacked immunomodulatory proteins. In some embodiments, the dimeric multi-domain stack immunomodulatory protein can be produced in cells by expression, or in some cases co-expression, of stack immunomodulatory Fc fusion polypeptides, such as described above in accord with generating dimeric Fc fusion proteins.


In some embodiments, the dimeric multi-domain stack immunomodulatory protein is divalent for each Fc region, monovalent for each subunit, or divalent for one subunit and tetravalent for the other.


In some embodiments, the dimeric multi-domain stack immunomodulatory protein is a homodimeric multi-domain stack Fc protein. In some embodiments, the dimeric multi-domain stack immunomodulatory protein comprises a first stack immunomodulatory Fc fusion polypeptide and a second stack immunomodulatory Fc fusion polypeptide in which the first and second polypeptide are the same. In some embodiments, the multi-domain stack molecule contains a first Fc fusion polypeptide containing a variant PD-L2 and a second IgSF domain and a second Fc fusion polypeptide containing the variant PD-L2 and the second IgSF domain. In some embodiments, the multi-domain stack molecule contains a first Fc fusion polypeptide containing a variant PD-L2, a second IgSF domain, and a third IgSF domain and a second Fc fusion polypeptide containing the variant PD-L2, the second IgSF domain, and the third IgSF domain. In some embodiments, the Fc portion of the first and/or second fusion polypeptide can be any Fc as described above. In some embodiments, the Fc portion or region of the first and second fusion polypeptide is the same.


In some embodiments, the multi-domain stack molecule is heterodimeric, comprising two different Fc fusion polypeptides, e.g. a first and a second Fc polypeptide, wherein at least one is an Fc polypeptide containing a is an Fc fusion polypeptide containing at least one variant PD-L2 polypeptide and/or at least one second IgSF domain (e.g. second variant IgSF domain). In some embodiments, the first or second Fc fusion polypeptide further contains a third IgSF domain (e.g. third variant IgSF domain). In some embodiments, the multi-domain stack molecule contains a first Fc fusion polypeptide containing a variant PD-L2 and a second Fc fusion polypeptide containing at a second IgSF domain, in which, in some cases, the first or second Fc fusion polypeptide additionally contains a third IgSF domain. In some embodiments, the multi-domain stack molecule contains a first Fc fusion polypeptide containing a variant PD-L2, a second IgSF domain, and in some cases, a third IgSF domain and a second Fc fusion polypeptide that is not linked to either a variant PD-L2 polypeptide or an additional IgSF domain. In some embodiments, the Fc portion or region of the first and second fusion polypeptide is the same. In some embodiments, the Fc portion or region of the first and second fusion polypeptide is different.


In some embodiments, the multi-domain stack molecule contains a first Fc fusion polypeptide containing 1, 2, 3, 4 or more variant PD-L2 polypeptides and 1, 2, 3, 4 or more additional IgSF domains, wherein the total number of IgSF domains in the first stack Fc fusion polypeptide is greater than 2, 3, 4, 5, 6 or more. In one example of such an embodiment, the second stack Fc polypeptide contains 1, 2, 3, 4 or more additional variant PD-L2 polypeptides and 1, 2, 3, 4 or more second IgSF domains, wherein the total number of IgSF domains in the second stack Fc fusion polypeptide is greater than 2, 3, 4, 5, 6 or more. In another example of such embodiments, the second Fc fusion polypeptide is not linked to either a variant PD-L2 polypeptide or additional IgSF domain.


In some embodiments, the heterodimeric stack molecule contains a first stack immunomodulatory Fc fusion polypeptide and a second stack immunomodulatory Fc fusion polypeptide in which the first and second polypeptide are different. In some embodiments, a heterodimeric stack molecule contains a first Fc polypeptide fusion containing an Fc region and a first variant PD-L2 polypeptide and/or second IgSF domain (e.g. second variant IgSF domain) and a second Fc polypeptide fusion containing an Fc region and the other of the first variant PD-L2 polypeptide or the second IgSF domain. In some embodiments, a heterodimeric stack molecule contains a first Fc polypeptide fusion containing an Fc region and a first variant PD-L2 polypeptide and/or second IgSF domain (e.g. second variant IgSF domain) and a second Fc subunit containing both the first variant PD-L2 polypeptide and second IgSF domain (e.g. second variant IgSF domain) but in a different orientation or configuration from the first Fc region. In some embodiments, the first and/or second Fc fusion polypeptide also contains a third IgSF domain (e.g. third variant IgSF domain).


In some embodiments, the Fc domain of one or both of the first and second stacked immunomodulatory Fc fusion polypeptide comprises a modification (e.g. substitution) such that the interface of the Fc molecule is modified to facilitate and/or promote heterodimerization. In some embodiments, modifications include introduction of a protuberance (knob) into a first Fc polypeptide and a cavity (hole) into a second Fc polypeptide such that the protuberance is positionable in the cavity to promote complexing of the first and second Fc-containing polypeptides. Amino acids targeted for replacement and/or modification to create protuberances or cavities in a polypeptide are typically interface amino acids that interact or contact with one or more amino acids in the interface of a second polypeptide.


In some embodiments, a sequence of amino acids is added preceding the Fc sequence for constructs in which the Fc sequence was the N-terminal portion of the sequence. In some cases, the sequence of amino acids HMSSVSAQ (SEQ ID NO:1190) is added immediately preceding the Fc sequence for constructs in which the Fc sequence was the N-terminal portion of the sequence. In some embodiments, a heterodimeric stack molecule contains a first Fc polypeptide fusion containing an Fc region (knob) and a first variant polypeptide and/or second IgSF domain (e.g. second variant IgSF domain) and a second Fc polypeptide fusion containing an Fc region (hole) and a stuffer sequence HMSSVSAQ (SEQ ID NO:1190) was added immediately preceding both Fc regions of the first and second Fc polypeptide fusion.


In some embodiments, a first polypeptide that is modified to contain protuberance (hole) amino acids include replacement of a native or original amino acid with an amino acid that has at least one side chain which projects from the interface of the first polypeptide and is therefore positionable in a compensatory cavity (hole) in an adjacent interface of a second polypeptide. Most often, the replacement amino acid is one which has a larger side chain volume than the original amino acid residue. One of skill in the art knows how to determine and/or assess the properties of amino acid residues to identify those that are ideal replacement amino acids to create a protuberance. In some embodiments, the replacement residues for the formation of a protuberance are naturally occurring amino acid residues and include, for example, arginine (R), phenylalanine (F), tyrosine (Y), or tryptophan (W). In some examples, the original residue identified for replacement is an amino acid residue that has a small side chain such as, for example, alanine, asparagine, aspartic acid, glycine, serine, threonine, or valine.


In some embodiments, a second polypeptide that is modified to contain a cavity (hole) is one that includes replacement of a native or original amino acid with an amino acid that has at least one side chain that is recessed from the interface of the second polypeptide and thus is able to accommodate a corresponding protuberance from the interface of a first polypeptide. Most often, the replacement amino acid is one which has a smaller side chain volume than the original amino acid residue. One of skill in the art knows how to determine and/or assess the properties of amino acid residues to identify those that are ideal replacement residues for the formation of a cavity. Generally, the replacement residues for the formation of a cavity are naturally occurring amino acids and include, for example, alanine (A), serine (S), threonine (T) and valine (V). In some examples, the original amino acid identified for replacement is an amino acid that has a large side chain such as, for example, tyrosine, arginine, phenylalanine, or tryptophan.


The CH3 interface of human IgG1, for example, involves sixteen residues on each domain located on four anti-parallel β-strands which buries 1090 Å2 from each surface (see e.g., Deisenhofer et al. (1981) Biochemistry, 20:2361-2370; Miller et al., (1990) J Mol. Biol., 216, 965-973; Ridgway et al., (1996) Prot. Engin., 9: 617-621; U.S. Pat. No. 5,731,168). Modifications of a CH3 domain to create protuberances or cavities are described, for example, in U.S. Pat. No. 5,731,168; International Patent Applications WO98/50431 and WO 2005/063816; and Ridgway et al., (1996) Prot. Engin., 9: 617-621. In some examples, modifications of a CH3 domain to create protuberances or cavities are typically targeted to residues located on the two central anti-parallel β-strands. The aim is to minimize the risk that the protuberances which are created can be accommodated by protruding into the surrounding solvent rather than being accommodated by a compensatory cavity in the partner CH3 domain.


In some embodiments, the heterodimeric molecule contains a T366W mutation in the CH3 domain of the “knobs chain” and T366S, L368A, Y407V mutations in the CH3 domain of the “hole chain”. In some cases, an additional interchain disulfide bridge between the CH3 domains can also be used (Merchant, A. M., et al., Nature Biotech. 16 (1998) 677-681) e.g. by introducing a Y349C mutation into the CH3 domain of the “knobs” or “hole” chain and a E356C mutation or a S354C mutation into the CH3 domain of the other chain. In some embodiments, the heterodimeric molecule contains S354C, T366W mutations in one of the two CH3 domains and Y349C, T366S, L368A, Y407V mutations in the other of the two CH3 domains. In some embodiments, the heterodimeric molecule comprises E356C, T366W mutations in one of the two CH3 domains and Y349C, T366S, L368A, Y407V mutations in the other of the two CH3 domains. In some embodiments, the heterodimeric molecule comprises Y349C, T366W mutations in one of the two CH3 domains and E356C, T366S, L368A, Y407V mutations in the other of the two CH3 domains. In some embodiments, the heterodimeric molecule comprises Y349C, T366W mutations in one of the two CH3 domains and S354C, T366S, L368A, Y407V mutations in the other of the two CH3 domains. Examples of other knobs-in-holes technologies are known in the art, e.g. as described by EP 1 870 459 A1.


In some embodiments, the Fc regions of the heterodimeric molecule additionally can contain one or more other Fc mutation, such as any described above. In some embodiments, the heterodimer molecule contains an Fc region with a mutation that reduces effector function.


In some embodiments, an Fc variant containing CH3 protuberance (knob) or cavity (hole) modifications can be joined to a stacked immunomodulatory polypeptide anywhere, but typically via its N- or C-terminus, to the N- or C-terminus of a first and/or second stacked immunomodulatory polypeptide, such as to form a fusion polypeptide. The linkage can be direct or indirect via a linker. Typically, a knob and hole molecule is generated by co-expression of a first stacked immunomodulatory polypeptide linked to an Fc variant containing CH3 protuberance modification(s) with a second stacked immunomodulatory polypeptide linked to an Fc variant containing CH3 cavity modification(s).


There is provided herein a homodimeric multi-domain stack molecule produced from a stack immunomodulatory Fc fusion polypeptide containing an IgSF domain, e.g. IgV domain, of a variant CD155 polypeptide and a second IgSF domain, e.g. IgV, of a variant PD-L2 polypeptide. In some embodiments, the first and second immunomodulatory Fc fusion polypeptide of the multi-domain stack molecule has the sequence set forth in any of SEQ ID NOS: 1191, 1192, 1193, 1194, 1195, or 1196 or a sequence of amino acids that has at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to any of SEQ ID NOS: 1191, 1192, 1193, 1194, 1195, or 1196 and contains the one more amino acid modifications in the variant PD-L2 and/or CD155 IgSF domain. In some embodiments, the resulting multi-domain stack molecules bind to both TIGIT and PD-1. In some aspects, the binding to TIGIT is to the same or similar degree or, in some cases, is increased, compared to the binding to TIGIT of the corresponding IgSF domain of unmodified or wild-type CD155. In some aspects, the binding to PD-1 is to the same or similar degree or, in some cases, is increased, compared to the binding to PD-1 of the corresponding IgSF domain of unmodified or wild-type PD-L1. In some embodiments, the binding to TIGIT or PD-1 is at least 30%, 40%, 50%, 60%, 70%, 80%, 90%, or more of the binding to TIGIT or PD-1 of the non-stacked form of the variant CD155 IgSF-Fc. In some embodiments, the binding to TIGIT is at least 30%, 40%, 50%, 60%, 70%, 80%, 90% or more of the binding to TIGIT of the non-stacked form of the variant CD155 IgSF-Fc. In some embodiments, the resulting multi-domain stack molecule increases T cell immune responses compared to the non-stack variant PD-L2 IgSF-Fc and/or variant CD155-IgSF-Fc, such as determined in a reporter assay. In some embodiments, the increase is greater than 1.2-fold, 1.3-fold, 1.4-fold, 1.5-fold, 2.0-fold, 3.0-fold, 4.0-fold, 5.0-fold or more.


There is provided herein a heterodimeric multi-domain stack molecule produced from a stack immunomodulatory Fc fusion polypeptide containing an IgSF domain, e.g. IgV domain, of a variant CD155 polypeptide and a second IgSF domain, e.g. IgV, of a variant PD-L2 polypeptide. In some embodiments, one of the first and second immunomodulatory Fc fusion polypeptide of the multi-domain stack molecule comprises a knob molecule that has the sequence set forth in any of SEQ ID NOS: 1197, 1198, 1199, 1200, 1201, or 1203, or a sequence of amino acids that has at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to any of SEQ ID NOS: 1197, 1198, 1199, 1200, 1201, or 1203, and contains the one more amino acid modifications in the variant PD-L2 and/or CD155 IgSF domain. In some embodiments, the other of the first and second immunomodulatory Fc fusion polypeptide of the multi-domain stack molecule comprises a hole molecule that has the sequence set forth in any of SEQ ID NOS: 1188, 1202, or 1204, or a sequence of amino acids that has at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to any of SEQ ID NOS: 1188, 1202, or 1204, and contains the one more amino acid modifications in the variant PD-L2 and/or CD155 IgSF domain. In some embodiments, the resulting multi-domain stack molecules bind to both TIGIT and PD-1. In some embodiments, the knob and hole molecules are expressed in various combinations and are generated by co-expression of a first stacked immunomodulatory polypeptide linked to an Fc variant containing CH3 protuberance modification(s) with a second stacked immunomodulatory polypeptide linked to an Fc variant containing CH3 cavity modification(s). For example, the first and second immunomodulatory Fc fusion polypeptide of the multi-domain stack molecule comprises a knob and hole molecule that has the pair of sequences set forth in any of SEQ ID NOS:1197+1188, 1198+1188, 1199+1188, 1200+1188, 1201+1202, 1203+1204, 1199+1204, 1199+1202, 1200+1202, 1200+1204, or a sequence of amino acids that has at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to any of the pairs of SEQ ID NOS: 1197+1188, 1198+1188, 1199+1188, 1200+1188, 1201+1202, 1203+1204, 1199+1204, 1199+1202, 1200+1202, 1200+1204, and contains the one more amino acid modifications in the variant PD-L2 and/or CD155 IgSF domain. In some cases, the knob or hole molecule includes a N-terminal HMSSVSAQ set forth in SEQ ID NO:1190. In some aspects, the binding to TIGIT is to the same or similar degree or, in some cases, is increased, compared to the binding to TIGIT of the corresponding IgSF domain of unmodified or wild-type CD155. In some aspects, the binding to PD-1 is to the same or similar degree or, in some cases, is increased, compared to the binding to PD-1 of the corresponding IgSF domain of unmodified or wild-type PD-L2. In some embodiments, the binding to TIGIT or PD-1 is at least 30%, 40%, 50%, 60%, 70%, 80%, 90%, or more of the binding to TIGIT or PD-1 of the non-stacked form of the variant CD155 IgSF-Fc. In some embodiments, the binding to TIGIT is at least 30%, 40%, 50%, 60%, 70%, 80%, 90% or more of the binding to TIGIT of the non-stacked form of the variant CD155 IgSF-Fc. In some embodiments, the resulting multi-domain stack molecule increases T cell immune responses compared to the non-stack variant PD-L2 IgSF-Fc and/or variant CD155-IgSF-Fc, such as determined in a reporter assay. In some embodiments, the increase is greater than 1.2-fold, 1.3-fold, 1.4-fold, 1.5-fold, 2.0-fold, 3.0-fold, 4.0-fold, 5.0-fold or more.


C. Conjugates and Fusions of Variant Polypeptides and Immunomodulatory Proteins


In some embodiments, the variant polypeptides provided herein, which are immunomodulatory proteins comprising variants of an Ig domain of the IgSF family (vIgD), can be conjugated with or fused with a moiety, such as an effector moiety, such as another protein, directly or indirectly, to form a conjugate (“IgSF conjugate”). In some embodiments, the attachment can be covalent or non-covalent, e.g., via a biotin-streptavidin non-covalent interaction. In some embodiments, the moiety can be a targeting moiety, a small molecule drug (non-polypeptide drug of less than 500 daltons molar mass), a toxin, a cytostatic agent, a cytotoxic agent, an immunosuppressive agent, a radioactive agent suitable for diagnostic purposes, a radioactive metal ion for therapeutic purposes, a prodrug-activating enzyme, an agent that increases biological half-life, or a diagnostic or detectable agent.


In some embodiments the effector moiety is a therapeutic agent, such as a cancer therapeutic agent, which is either cytotoxic, cytostatic or otherwise provides some therapeutic benefit. In some embodiments, the effector moiety is a targeting moiety or agent, such as an agent that targets a cell surface antigen, e.g., an antigen on the surface of a tumor cell. In some embodiments, the effector moiety is a label, which can generate a detectable signal, either directly or indirectly. In some embodiments, the effector moiety is a toxin. In some embodiments, the effector moiety is a protein, peptide, nucleic acid, small molecule or nanoparticle.


In some embodiments, 1, 2, 3, 4, 5 or more effector moieties, which can be the same or different, are conjugated, linked or fused to the variant polypeptide or protein to form an IgSF conjugate. In some embodiments, such effector moieties can be attached to the variant polypeptide or immunomodulatory protein using various molecular biological or chemical conjugation and linkage methods known in the art and described below. In some embodiments, linkers such as peptide linkers, cleavable linkers, non-cleavable linkers or linkers that aid in the conjugation reaction, can be used to link or conjugate the effector moieties to the variant polypeptide or immunomodulatory protein.


In some embodiments, the IgSF conjugate comprises the following components: (protein or polypeptide), (L)q and (effector moiety)m, wherein the protein or polypeptide is any of the described variant polypeptides or immunomodulatory proteins capable of binding one or more cognate counter structure ligands as described; L is a linker for linking the protein or polypeptide to the moiety; m is at least 1; q is 0 or more; and the resulting IgSF conjugate binds to the one or more counter structure ligands. In particular embodiments, m is 1 to 4 and q is 0 to 8.


In some embodiments, there is provided an IgSF conjugate comprising a variant polypeptide or immunomodulatory protein provided herein conjugated with a targeting agent that binds to a cell surface molecule, for example, for targeted delivery of the variant polypeptide or immunomodulatory protein to a specific cell. In some embodiments, the targeting agent is a molecule(s) that has the ability to localize and bind to a molecule present on a normal cell/tissue and/or tumor cell/tumor in a subject. In other words, IgSF conjugates comprising a targeting agent can bind to a ligand (directly or indirectly), which is present on a cell, such as a tumor cell. The targeting agents of the invention contemplated for use include antibodies, polypeptides, peptides, aptamers, other ligands, or any combination thereof, that can bind a component of a target cell or molecule.


In some embodiments, the targeting agent binds a tumor cell(s) or can bind in the vicinity of a tumor cell(s) (e.g., tumor vasculature or tumor microenvironment) following administration to the subject. The targeting agent may bind to a receptor or ligand on the surface of the cancer cell. In another aspect of the invention, a targeting agent is selected which is specific for a noncancerous cells or tissue. For example, a targeting agent can be specific for a molecule present normally on a particular cell or tissue. Furthermore, in some embodiments, the same molecule can be present on normal and cancer cells. Various cellular components and molecules are known. For example, if a targeting agent is specific for EGFR, the resulting IgSF conjugate can target cancer cells expressing EGFR as well as normal skin epidermal cells expressing EGFR. Therefore, in some embodiments, an IgSF conjugate of the invention can operate by two separate mechanisms (targeting cancer and non-cancer cells).


In various aspects of the invention disclosed herein an IgSF conjugate of the invention comprises a targeting agent which can bind/target a cellular component, such as a tumor antigen, a bacterial antigen, a viral antigen, a mycoplasm antigen, a fungal antigen, a prion antigen, an antigen from a parasite. In some aspects, a cellular component, antigen or molecule can each be used to mean, a desired target for a targeting agent. For example, in various embodiments, a targeting agent is specific for or binds to a component, which includes but is not limited to, epidermal growth factor receptor (EGFR, ErbB-1, HER1), ErbB-2 (HER2/neu), ErbB-3/HER3, ErbB-4/HER4, EGFR ligand family; insulin-like growth factor receptor (IGFR) family, IGF-binding proteins (IGFBPs), IGFR ligand family; platelet derived growth factor receptor (PDGFR) family, PDGFR ligand family; fibroblast growth factor receptor (FGFR) family, FGFR ligand family, vascular endothelial growth factor receptor (VEGFR) family, VEGF family; HGF receptor family; TRK receptor family; ephrin (EPH) receptor family; AXL receptor family; leukocyte tyrosine kinase (LTK) receptor family; TIE receptor family, angiopoietin 1,2; receptor tyrosine kinase-like orphan receptor (ROR) receptor family, e.g. ROR1; CD171 (L1CAM); B7-H6 (NCR3LG1); PD-L2, tumor glycosylation antigen, e.g. sTn or Tn, such as sTn Ag of MUC1; LHR (LHCGR); phosphatidylserine, discoidin domain receptor (DDR) family; RET receptor family; KLG receptor family; RYK receptor family; MuSK receptor family; Transforming growth factor-α (TGF-α) receptors, TGF-β; Cytokine receptors, Class I (hematopoietin family) and Class II (interferon/IL-10 family) receptors, tumor necrosis factor (TNF) receptor superfamily (TNFRSF), death receptor family; cancer-testis (CT) antigens, lineage-specific antigens, differentiation antigens, alpha-actinin-4, ARTC1, breakpoint cluster region-Abelson (Bcr-abl) fusion products, B-RAF, caspase-5 (CASP-5), caspase-8 (CASP-8), β-catenin (CTNNB1), cell division cycle 27 (CDC27), cyclin-dependent kinase 4 (CDK4), CDKN2A, COA-I, dek-can fusion protein, EFTUD-2, Elongation factor 2 (ELF2), Ets variant gene 6/acute myeloid leukemia 1 gene ETS (ETC6-AML1) fusion protein, fibronectin (FN), e.g. the extradomain A (EDA) of fibronectin, GPNMB, low density lipid receptor/GDP-L fucose: β-D-galactose 2-α-L-fucosyltransferase (LDLR/FUT) fusion protein, HLA-A2. arginine to isoleucine exchange at residue 170 of the α-helix of the α2-domain in the HLA-A2gene (HLA-A*201-R170I), HLA-Al 1, heat shock protein 70-2 mutated (HSP70-2M), K1AA0205, MART2, melanoma ubiquitous mutated 1, 2, 3 (MUM-I, 2, 3), prostatic acid phosphatase (PAP), neo-PAP, Myosin class I, NFYC, OGT, OS-9, pml-RARα fusion protein, PRDX5, PTPRK, K-ras (KRAS2), N-ras (NRAS), HRAS, RBAF600, SIRT2, SNRPD1, SYT-SSX1 or -SSX2 fusion protein, Triosephosphate Isomerase, BAGE, BAGK-1, BAGE-2,3,4,5, GAGE-1,2,3,4,5,6,7,8, GnT-V (aberrant N-acetyl glucosaminyl transferase V, MGAT5), HERV-K-MEL, KK-LC, KM-HN-I, LAGE, LAGE-I, CTL-recognized antigen on melanoma (CAMEL), MAGE-A1 (MAGE-I), MAGE-A2, MAGE-A3, MAGE-A4, MAGE-A5, MAGE-A6, MAGE-A8, MAGE-A9, MAGE-AlO, MAGE-AI1, MAGE-A12, MAGE-3, MAGE-B1, MAGE-B2, MAGE-B5, MAGE-B6, MAGE-C1, MAGE-C2, mucin 1 (MUC1), MART-1/Melan-A (MLANA), gplOO, gplOO/Pmell7 (SILV), tyrosinase (TYR), TRP-I, HAGE, NA-88, NY-ESO-I, NY-ESO-1/LAGE-2, SAGE, Spl7, SSX-1,2,3,4, TRP2-INT2, carcino-embryonic antigen (CEA), Kallikrein 4, mammaglobin-A, OA1, prostate specific antigen (PSA), TRP-1/gp75, TRP-2, adipophilin, interferon inducible protein absent in melanoma 2 (AIM-2), BING-4, CPSF, cyclin Dl, epithelial cell adhesion molecule (Ep-CAM), EphA3, fibroblast growth factor-5 (FGF-5), glycoprotein 250 (gp250), EGFR (ERBB1), HER-2/neu (ERBB2), interleukin 13 receptor α2 chain (IL13Rα2), IL-6 receptor, intestinal carboxyl esterase (iCE), alpha-feto protein (AFP), M-CSF, mdm-2, MUCl, p53 (TP53), PBF, PRAME, PSMA, RAGE-I, RNF43, RU2AS, SOXlO, STEAPl, survivin (BIRC5), human telomerase reverse transcriptase (hTERT), telomerase, Wilms' tumor gene (WT1), SYCP1, BRDT, SPANX, XAGE, ADAM2, PAGE-5, LIPl, CTAGE-I, CSAGE, MMAl, CAGE, BORIS, HOM-TES-85, AF15q14, HCA661, LDHC, MORC, SGY-I, SPOl 1, TPX1, NY-SAR-35, FTHL17, NXF2, TDRD1, TEX15, FATE, TPTE, immunoglobulin idiotypes, Bence-Jones protein, estrogen receptors (ER), androgen receptors (AR), CD40, CD30, CD20, CD 19, CD33, cancer antigen 72-4 (CA 72-4), cancer antigen 15-3 (CA 15-3), cancer antigen 27-29 (CA 27-29), cancer antigen 125 (CA 125), cancer antigen 19-9 (CA 19-9), β-human chorionic gonadotropin, β-2 microglobulin, squamous cell carcinoma antigen, neuron-specific enolase, heat shock protein gp96, GM2, sargramostim, CTLA-4, 707 alanine proline (707-AP), adenocarcinoma antigen recognized by T cells 4 (ART-4), carcinoembryogenic antigen peptide-1 (CAP-I), calcium-activated chloride channel-2 (CLCA2), cyclophilin B (Cyp-B), human signet ring tumor-2 (HST-2), Human papilloma virus (HPV) proteins (HPV-E6, HPV-E7, major or minor capsid antigens, others), Epstein-Barr virus (EBV) proteins (EBV latent membrane proteins—LMP1, LMP2; others), Hepatitis B or C virus proteins, and HIV proteins.


In some embodiments, an IgSF conjugate, through its targeting agent, will bind a cellular component of a tumor cell, tumor vasculature or tumor microenvironment, thereby promoting killing of targeted cells via modulation of the immune response, (e.g., by activation of co-stimulatory molecules or inhibition of negative regulatory molecules of immune cell activation), inhibition of survival signals (e.g., growth factor or cytokine or hormone receptor antagonists), activation of death signals, and/or immune-mediated cytotoxicity, such as through antibody dependent cellular cytotoxicity. Such IgSF conjugates can function through several mechanisms to prevent, reduce or eliminate tumor cells, such as to facilitate delivery of conjugated effector moieties to the tumor target, such as through receptor-mediated endocytosis of the IgSF conjugate; or such conjugates can recruit, bind, and/or activate immune cells (e.g. NK cells, monocytes/macrophages, dendritic cells, T cells, B cells). Moreover, in some instances one or more of the foregoing pathways may operate upon administration of one or more IgSF conjugates of the invention.


In some embodiments, an IgSF conjugate, through its targeting agent, will be localized to, such as bind to, a cellular component of a tumor cell, tumor vasculature or tumor microenvironment, thereby modulating cells of the immune response in the vicinity of the tumor. In some embodiments, the targeting agent facilitates delivery of the conjugated IgSF (e.g. vIgD) to the tumor target, such as to interact with its cognate binding partner to alter signaling of immune cells (e.g. NK cells, monocytes/macrophages, dendritic cells, T cells, B cells) bearing the cognate binding partner. In some embodiments, localized delivery mediates an antagonizing or blocking activity of the PD-1 inhibitory receptor. In some embodiments, localized delivery agonizes the PD-1 inhibitory receptor, which, in some cases, can occur where there is proximal clustering of an activating receptor.


In some embodiments, the targeting agent is an immunoglobulin. As used herein, the term “immunoglobulin” includes natural or artificial mono- or polyvalent antibodies including, but not limited to, polyclonal, monoclonal, multispecific, human, humanized or chimeric antibodies, single chain antibodies, Fab fragments, F(ab′) fragments, fragments produced by a Fab expression library, single chain Fv (scFv); anti-idiotypic (anti-Id) antibodies (including, e.g., anti-Id antibodies to antibodies of the invention), and epitope-binding fragments of any of the above. The term “antibody,” as used herein, refers to immunoglobulin molecules and immunologically active portions of immunoglobulin molecules, e.g., molecules that contain an antigen binding site that immunospecifically binds an antigen. The immunoglobulin molecules of the invention can be of any type (e.g., IgG, IgE, IgM, IgD, IgA, and IgY), class (e.g., IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2) or subclass of immunoglobulin molecule.


In some embodiments, an IgSF conjugate, through its antibody targeting moiety, will bind a cellular component of a tumor cell, tumor vasculature or tumor microenvironment, thereby promoting apoptosis of targeted cells via modulation of the immune response, (e.g., by activation of co-stimulatory molecules or inhibition of negative regulatory molecules of immune cell activation), inhibition of survival signals (e.g., growth factor or cytokine or hormone receptor antagonists), activation of death signals, and/or immune-mediated cytotoxicity, such as through antibody dependent cellular cytotoxicity. Such IgSF conjugates can function through several mechanisms to prevent, reduce or eliminate tumor cells, such as to facilitate delivery of conjugated effector moieties to the tumor target, such as through receptor-mediated endocytosis of the IgSF conjugate; or such conjugates can recruit, bind, and/or activate immune cells (e.g. NK cells, monocytes/macrophages, dendritic cells, T cells, B cells).


In some embodiments, an IgSF conjugate, through its antibody targeting moiety, will bind a cellular component of a tumor cell, tumor vasculature or tumor microenvironment, thereby modulating the immune response (e.g., by activation of co-stimulatory molecules or inhibition of negative regulatory molecules of immune cell activation). In some embodiments, such conjugates can recognize, bind, and/or modulate (e.g. inhibit or activate) immune cells (e.g. NK cells, monocytes/macrophages, dendritic cells, T cells, B cells).


Antibody targeting moieties of the invention include antibody fragments that include, but are not limited to, Fab, Fab′ and F(ab′)2, Fd, single-chain Fvs (scFv), single-chain antibodies, disulfide-linked Fvs (sdFv) and fragments comprising either a VL or VH domain. Antigen-binding antibody fragments, including single-chain antibodies, may comprise the variable region(s) alone or in combination with the entirety or a portion of the following: hinge region, CH1, CH2, and CH3 domains. Also included in the invention are antigen-binding fragments also comprising any combination of variable region(s) with a hinge region, CH1, CH2, and CH3 domains. Also included in the invention are Fc fragments, antigen-Fc fusion proteins, and Fc-targeting moiety conjugates or fusion products (Fc-peptide, Fc-aptamer). The antibody targeting moieties of the invention may be from any animal origin including birds and mammals. In one aspect, the antibody targeting moieties are human, murine (e.g., mouse and rat), donkey, sheep, rabbit, goat, guinea pig, camel, horse, or chicken. Further, such antibodies may be humanized versions of animal antibodies. The antibody targeting moieties of the invention may be monospecific, bispecific, trispecific, or of greater multispecificity.


In various embodiments, an antibody/targeting moiety recruits, binds, and/or activates immune cells (e.g. NK cells, monocytes/macrophages, dendritic cells) via interactions between Fc (in antibodies) and Fc receptors (on immune cells) and via the conjugated variant polypeptides or immunomodulatory proteins provided herein. In some embodiments, an antibody/targeting moiety recognizes or binds a tumor agent via and localizes to the tumor cell the conjugated variant polypeptides or immunomodulatory proteins provided herein to facilitate modulation of immune cells in the vicinity of the tumor.


Examples of antibodies which can be incorporated into IgSF conjugates include but are not limited to antibodies such as Cetuximab (IMC-C225; Erbitux®), Trastuzumab (Herceptin®), Rituximab (Rituxan®; MabThera®), Bevacizumab (Avastin®), Alemtuzumab (Campath®; Campath-1H®; Mabcampath®), Panitumumab (ABX-EGF; Vectibix®), Ranibizumab (Lucentis®), Ibritumomab, Ibritumomab tiuxetan, (Zevalin®), Tositumomab, Iodine I 131 Tositumomab (BEXXAR®), Catumaxomab (Removab®), Gemtuzumab, Gemtuzumab ozogamicine (Mylotarg®), Abatacept (CTLA4-Ig; Orencia®), Belatacept (L104EA29YIg; LEA29Y; LEA), Ipilimumab (MDX-010; MDX-101), Tremelimumab (ticilimumab; CP-675,206), PRS-010, PRS-050, Aflibercept (VEGF Trap, AVE005), Volociximab (M200), F200, MORAb-009, SS1P (CAT-5001), Cixutumumab (IMC-A12), Matuzumab (EMD72000), Nimotuzumab (h-R3), Zalutumumab (HuMax-EGFR), Necitumumab IMC-11F8, mAb806/ch806, Sym004, mAb-425, Panorex @ (17-1A) (murine monoclonal antibody); Panorex @ (17-1A) (chimeric murine monoclonal antibody); IDEC-Y2B8 (murine, anti-CD2O MAb); BEC2 (anti-idiotypic MAb, mimics the GD epitope) (with BCG); Oncolym (Lym-1 monoclonal antibody); SMART MI95 Ab, humanized 13′ I LYM-I (Oncolym), Ovarex (B43.13, anti-idiotypic mouse MAb); MDX-210 (humanized anti-HER-2 bispecific antibody); 3622W94 MAb that binds to EGP40 (17-1A) pancarcinoma antigen on adenocarcinomas; Anti-VEGF, Zenapax (SMART Anti-Tac (IL-2 receptor); SMART MI95 Ab, humanized Ab, humanized); MDX-210 (humanized anti-HER-2 bispecific antibody); MDX-447 (humanized anti-EGF receptor bispecific antibody); NovoMAb-G2 (pancarcinoma specific Ab); TNT (chimeric MAb to histone antigens); TNT (chimeric MAb to histone antigens); Gliomab-H (Monoclon s-Humanized Abs); GNI-250 Mab; EMD-72000 (chimeric-EGF antagonist); LymphoCide (humanized LL2 antibody); and MDX-260 bispecific, targets GD-2, ANA Ab, SMART ID1O Ab, SMART ABL 364 Ab or ImmuRAIT-CEA. As illustrated by the forgoing list, it is conventional to make antibodies to a particular target epitope.


In some embodiments, the antibody targeting moiety is a full length antibody, or antigen-binding fragment thereof, containing an Fc domain. In some embodiments, the variant polypeptide or immunomodulatory protein is conjugated to the Fc portion of the antibody targeting moiety, such as by conjugation to the N-terminus of the Fc portion of the antibody.


In some embodiments, the vIgD is linked, directly or indirectly, to the N- or C-terminus of the light and/or heavy chain of the antibody. In some embodiments, linkage can be via a peptide linker, such as any described above. Various configurations can be constructed. FIG. 7A-7C depict exemplary configurations. In some embodiments, the antibody conjugate can be produced by co-expression of the heavy and light chain of the antibody in a cell.


In one aspect of the invention, the targeting agent is an aptamer molecule. For example, in some embodiments, the aptamer is comprised of nucleic acids that function as a targeting agent. In various embodiments, an IgSF conjugate of the invention comprises an aptamer that is specific for a molecule on a tumor cell, tumor vasculature, and/or a tumor microenvironment. In some embodiments, the aptamer itself can comprise a biologically active sequence, in addition to the targeting module (sequence), wherein the biologically active sequence can induce an immune response to the target cell. In other words, such an aptamer molecule is a dual use agent. In some embodiments, an IgSF conjugate of the invention comprises conjugation of an aptamer to an antibody, wherein the aptamer and the antibody are specific for binding to separate molecules on a tumor cell, tumor vasculature, tumor microenvironment, and/or immune cells.


The term “aptamer” includes DNA, RNA or peptides that are selected based on specific binding properties to a particular molecule. For example, an aptamer(s) can be selected for binding a particular gene or gene product in a tumor cell, tumor vasculature, tumor microenvironment, and/or an immune cell, as disclosed herein, where selection is made by methods known in the art and familiar to one of skill in the art.


In some aspects of the invention the targeting agent is a peptide. For example, the variant polypeptides or immunomodulatory proteins provided herein can be conjugated to a peptide which can bind with a component of a cancer or tumor cells. Therefore, such IgSF conjugates of the invention comprise peptide targeting agents which binds to a cellular component of a tumor cell, tumor vasculature, and/or a component of a tumor microenvironment. In some embodiments, targeting agent peptides can be an antagonist or agonist of an integrin. Integrins, which comprise an alpha and a beta subunit, include numerous types well known to a skilled artisan.


In one embodiment, the targeting agent is Vvβ3. Integrin Vvβ3 is expressed on a variety of cells and has been shown to mediate several biologically relevant processes, including adhesion of osteoclasts to bone matrix, migration of vascular smooth muscle cells, and angiogenesis. Suitable targeting molecules for integrins include RGD peptides or peptidomimetics as well as non-RGD peptides or peptidomimetics (see, e.g., U.S. Pat. Nos. 5,767,071 and 5,780,426) for other integrins such as V4.βi (VLA-4), V4-P7 (see, e.g., U.S. Pat. No. 6,365,619; Chang et al, Bioorganic & Medicinal Chem Lett, 12:159-163 (2002); Lin et al., Bioorganic & Medicinal Chem Lett, 12:133-136 (2002)), and the like.


In some embodiments, there is provided an IgSF conjugate comprising a variant polypeptide or immunomodulatory protein provided herein conjugated with a therapeutic agent. In some embodiments, the therapeutic agent includes, for example, daunomycin, doxorubicin, methotrexate, and vindesine (Rowland et al., Cancer Immunol. Immunother. 21:183-187, 1986). In some embodiments, the therapeutic agent has an intracellular activity. In some embodiments, the IgSF conjugate is internalized and the therapeutic agent is a cytotoxin that blocks the protein synthesis of the cell, therein leading to cell death. In some embodiments, the therapeutic agent is a cytotoxin comprising a polypeptide having ribosome-inactivating activity including, for example, gelonin, bouganin, saporin, ricin, ricin A chain, bryodin, diphtheria toxin, restrictocin, Pseudomonas exotoxin A and variants thereof. In some embodiments, where the therapeutic agent is a cytotoxin comprising a polypeptide having a ribosome-inactivating activity, the IgSF conjugate must be internalized upon binding to the target cell in order for the protein to be cytotoxic to the cells.


In some embodiments, there is provided an IgSF conjugate comprising a variant polypeptide or immunomodulatory protein provided herein conjugated with a toxin. In some embodiments, the toxin includes, for example, bacterial toxins such as diphtheria toxin, plant toxins such as ricin, small molecule toxins such as geldanamycin (Mandler et al., J. Nat. Cancer Inst. 92(19):1573-1581 (2000); Mandler et al., Bioorganic & Med. Chem. Letters 10:1025-1028 (2000); Mandler et al., Bioconjugate Chem. 13:786-791 (2002)), maytansinoids (EP 1391213; Liu et al., Proc. Natl. Acad. Sci. USA 93:8618-8623 (1996)), and calicheamicin (Lode et al., Cancer Res. 58:2928 (1998); Hinman et al., Cancer Res. 53:3336-3342 (1993)). The toxins may exert their cytotoxic and cytostatic effects by mechanisms including tubulin binding, DNA binding, or topoisomerase inhibition.


In some embodiments, there is provided an IgSF conjugate comprising a variant polypeptide or immunomodulatory protein provided herein conjugated with a label, which can generate a detectable signal, indirectly or directly. These IgSF conjugates can be used for research or diagnostic applications, such as for the in vivo detection of cancer. The label is preferably capable of producing, either directly or indirectly, a detectable signal. For example, the label may be radio-opaque or a radioisotope, such as 3H, 14C, 32P, 35S, 123I, 125I, 131I; a fluorescent (fluorophore) or chemiluminescent (chromophore) compound, such as fluorescein isothiocyanate, rhodamine or luciferin; an enzyme, such as alkaline phosphatase, β-galactosidase or horseradish peroxidase; an imaging agent; or a metal ion. In some embodiments, the label is a radioactive atom for scintigraphic studies, for example 99Tc or 123I, or a spin label for nuclear magnetic resonance (NMR) imaging (also known as magnetic resonance imaging, MRI), such as zirconium-89, iodine-123, iodine-131, indium-111, fluorine-19, carbon-13, nitrogen-15, oxygen-17, gadolinium, manganese or iron. Zirconium-89 may be complexed to various metal chelating agents and conjugated to antibodies, e.g., for PET imaging (WO 2011/056983). In some embodiments, the IgSF conjugate is detectable indirectly. For example, a secondary antibody that is specific for the IgSF conjugate and contains a detectable label can be used to detect the IgSF conjugate.


The IgSF conjugates may be prepared using any methods known in the art. See, e.g., WO 2009/067800, WO 2011/133886, and U.S. Patent Application Publication No. 2014322129, incorporated by reference herein in their entirety.


The variant polypeptides or immunomodulatory proteins of an IgSF conjugate may be “attached to” the effector moiety by any means by which the variant polypeptides or immunomodulatory proteins can be associated with, or linked to, the effector moiety. For example, the variant polypeptides or immunomodulatory proteins of an IgSF conjugate may be attached to the effector moiety by chemical or recombinant means. Chemical means for preparing fusions or conjugates are known in the art and can be used to prepare the IgSF conjugate. The method used to conjugate the variant polypeptides or immunomodulatory proteins and effector moiety must be capable of joining the variant polypeptides or immunomodulatory proteins with the effector moiety without interfering with the ability of the variant polypeptides or immunomodulatory proteins to bind to their one or more counter structure ligands.


The variant polypeptides or immunomodulatory proteins of an IgSF conjugate may be linked indirectly to the effector moiety. For example, the variant polypeptides or immunomodulatory proteins of an IgSF conjugate may be directly linked to a liposome containing the effector moiety of one of several types. The effector moiety(s) and/or the variant polypeptides or immunomodulatory proteins may also be bound to a solid surface.


In some embodiments, the variant polypeptides or immunomodulatory proteins of an IgSF conjugate and the effector moiety are both proteins and can be conjugated using techniques well known in the art. There are several hundred crosslinkers available that can conjugate two proteins. (See for example “Chemistry of Protein Conjugation and Crosslinking,” 1991, Shans Wong, CRC Press, Ann Arbor). The crosslinker is generally chosen based on the reactive functional groups available or inserted on the variant polypeptides or immunomodulatory proteins and/or effector moiety. In addition, if there are no reactive groups, a photoactivatible crosslinker can be used. In certain instances, it may be desirable to include a spacer between the variant polypeptides or immunomodulatory proteins and the effector moiety. Crosslinking agents known to the art include the homobifunctional agents: glutaraldehyde, dimethyladipimidate and Bi s(diazobenzidine) and the heterobifunctional agents: m Maleimidobenzoyl-N-Hydroxysuccinimide and Sulfo-m Maleimidobenzoyl-N-Hydroxysuccinimide.


In some embodiments, the variant polypeptides or immunomodulatory proteins of an IgSF conjugate may be engineered with specific residues for chemical attachment of the effector moiety. Specific residues used for chemical attachment of molecule known to the art include lysine and cysteine. The crosslinker is chosen based on the reactive functional groups inserted on the variant polypeptides or immunomodulatory proteins, and available on the effector moiety.


An IgSF conjugate may also be prepared using recombinant DNA techniques. In such a case a DNA sequence encoding the variant polypeptides or immunomodulatory proteins is fused to a DNA sequence encoding the effector moiety, resulting in a chimeric DNA molecule. The chimeric DNA sequence is transfected into a host cell that expresses the fusion protein. The fusion protein can be recovered from the cell culture and purified using techniques known in the art.


Examples of attaching an effector moiety, which is a label, to the variant polypeptides or immunomodulatory proteins include the methods described in Hunter, et al., Nature 144:945 (1962); David, et al., Biochemistry 13:1014 (1974); Pain, et al., J. Immunol. Meth. 40:219 (1981); Nygren, J. Histochem. and Cytochem. 30:407 (1982); Wensel and Meares, Radioimmunoimaging And Radioimmunotherapy, Elsevier, N.Y. (1983); and Colcher et al., “Use Of Monoclonal Antibodies As Radiopharmaceuticals For The Localization Of Human Carcinoma Xenografts In Athymic Mice”, Meth. Enzymol., 121:802-16 (1986).


The radio- or other labels may be incorporated in the conjugate in known ways. For example, the peptide may be biosynthesized or may be synthesized by chemical amino acid synthesis using suitable amino acid precursors involving, for example, fluorine-19 in place of hydrogen. Labels such as 99Tc or 123I, 186Re, 188Re and 111In can be attached via a cysteine residue in the peptide. Yttrium-90 can be attached via a lysine residue. The IODOGEN method (Fraker et al., Biochem. Biophys. Res. Commun. 80:49-57 (1978)) can be used to incorporate iodine-123. “Monoclonal Antibodies in Immunoscintigraphy” (Chatal, CRC Press 1989) describes other methods in detail.


Conjugates of the variant polypeptides or immunomodulatory proteins and a cytotoxic agent may be made using a variety of bifunctional protein coupling agents such as N-succinimidyl-3-(2-pyridyldithio) propionate (SPDP), succinimidyl-4-(N-maleimidomethyl) cyclohexane-1-carboxylate (SMCC), iminothiolane (IT), bifunctional derivatives of imidoesters (such as dimethyl adipimidate HCl), active esters (such as disuccinimidyl suberate), aldehydes (such as glutaraldehyde), bis-azido compounds (such as bis (p-azidobenzoyl) hexanediamine), bis-diazonium derivatives (such as bis-(p-diazoniumbenzoyl)-ethylenediamine), diisocyanates (such as toluene 2,6-diisocyanate), and bis-active fluorine compounds (such as 1,5-difluoro-2,4-dinitrobenzene). For example, a ricin immunotoxin can be prepared as described in Vitetta et al., Science 238:1098 (1987). Carbon-14-labeled 1-p-isothiocyanatobenzyl-3-methyldiethylenetriaminepentaacetic acid (MX-DTPA) is an exemplary chelating agent for conjugation of radionucleotide to the antibody. See, e.g., WO94/11026. The linker may be a “cleavable linker” facilitating release of the cytotoxic drug in the cell. For example, an acid-labile linker, peptidase-sensitive linker, photolabile linker, dimethyl linker or disulfide-containing linker (Chari et al., Cancer Research 52:127-131 (1992); U.S. Pat. No. 5,208,020) may be used.


The IgSF conjugates of the invention expressly contemplate, but are not limited to, drug conjugates prepared with cross-linker reagents: BMPS, EMCS, GMBS, HBVS, LC-SMCC, MBS, MPBH, SBAP, SIA, SIAB, SMCC, SMPB, SMPH, sulfo-EMCS, sulfo-GMBS, sulfo-KMUS, sulfo-MBS, sulfo-SIAB, sulfo-SMCC, and sulfo-SMPB, and SVSB (succinimidyl-(4-vinylsulfone)benzoate) which are commercially available (e.g., from Pierce Biotechnology, Inc., Rockford, Ill., U.S.A). See pages 467-498, 2003-2004 Applications Handbook and Catalog.


D. Transmembrane and Secretable Immunomodulatory Proteins and Engineered Cells


Provided herein are engineered cells which express the immunomodulatory variant PD-L2 polypeptides (alternatively, “engineered cells”). In some embodiments, the expressed immunomodulatory variant PD-L2 polypeptide is a transmembrane protein and is surface expressed. In some embodiments, the immunomodulatory variant PD-L2 polypeptide is expressed and secreted from the cell.


1. Transmembrane Immunomodulatory Proteins


In some embodiments, an immunomodulatory polypeptide comprising a variant PD-L2 can be a membrane bound protein. As described in more detail below, the immunomodulatory polypeptide can be a transmembrane immunomodulatory polypeptide comprising a variant PD-L2 in which is contained: an ectodomain containing at least one affinity modified IgSF domain (IgV or IgC), a transmembrane domain and, optionally, a cytoplasmic domain. In some embodiments, the transmembrane immunomodulatory protein can be expressed on the surface of an immune cell, such as a mammalian cell, including on the surface of a lymphocyte (e.g. T cell or NK cell) or antigen presenting cell. In some embodiments, the transmembrane immunomodulatory protein is expressed on the surface of a mammalian T-cell, including such T-cells as: a T helper cell, a cytotoxic T-cell (alternatively, cytotoxic T lymphocyte or CTL), a natural killer T-cell, a regulatory T-cell, a memory T-cell, or a gamma delta T-cell. In some embodiments, the mammalian cell is an antigen presenting cell (APC). Typically, but not exclusively, the ectodomain (alternatively, “extracellular domain”) of comprises the one or more amino acid variations (e.g. amino acid substitutions) of the variant PD-L2 of the invention. Thus, for example, in some embodiments a transmembrane protein will comprise an ectodomain that comprises one or more amino acid substitutions of a variant PD-L2 of the invention.


In some embodiments, the engineered cells express a variant PD-L2 polypeptides are transmembrane immunomodulatory polypeptides (TIPs) that can be a membrane protein such as a transmembrane protein. In typical embodiments, the ectodomain of a membrane protein comprises an extracellular domain or IgSF domain thereof of a variant PD-L2 provided herein in which is contained one or more amino acid substitutions in at least one IgSF domain as described. The transmembrane immunomodulatory proteins provided herein further contain a transmembrane domain linked to the ectodomain. In some embodiments, the transmembrane domain results in an encoded protein for cell surface expression on a cell. In some embodiments, the transmembrane domain is linked directly to the ectodomain. In some embodiments, the transmembrane domain is linked indirectly to the ectodomain via one or more linkers or spacers. In some embodiments, the transmembrane domain contains predominantly hydrophobic amino acid residues, such as leucine and valine.


In some embodiments, a full length transmembrane anchor domain can be used to ensure that the TIPs will be expressed on the surface of the engineered cell, such as engineered T cell. Conveniently, this could be from a particular native protein that is being affinity modified (e.g. PD-L2 or other native IgSF protein), and simply fused to the sequence of the first membrane proximal domain in a similar fashion as the native IgSF protein (e.g. PD-L2). In some embodiments, the transmembrane immunomodulatory protein comprises a transmembrane domain of the corresponding wild-type or unmodified IgSF member, such as a transmembrane domain contained in the sequence of amino acids set forth in SEQ ID NO:4 (Table 2). In some embodiments, the membrane bound form comprises a transmembrane domain of the corresponding wild-type or unmodified polypeptide, such as corresponding to residues 221-241 of SEQ ID NO:4.


In some embodiments, the transmembrane domain is a non-native transmembrane domain that is not the transmembrane domain of native PD-L2. In some embodiments, the transmembrane domain is derived from a transmembrane domain from another non-PD-L2 family member polypeptide that is a membrane-bound or is a transmembrane protein. In some embodiments, a transmembrane anchor domain from another protein on T cells can be used. In some embodiments, the transmembrane domain is derived from CD8. In some embodiments, the transmembrane domain can further contain an extracellular portion of CD8 that serves as a spacer domain. An exemplary CD8 derived transmembrane domain is set forth in SEQ ID NO: 266 or 1212 or a portion thereof containing the CD8 transmembrane domain. In some embodiments, the transmembrane domain is a synthetic transmembrane domain.


In some embodiments, the transmembrane immunomodulatory protein further contains an endodomain, such as a cytoplasmic signaling domain, linked to the transmembrane domain. In some embodiments, the cytoplasmic signaling domain induces cell signaling. In some embodiments, the endodomain of the transmembrane immunomodulatory protein comprises the cytoplasmic domain of the corresponding wild-type or unmodified polypeptide, such as a cytoplasmic domain contained in the sequence of amino acids set forth in SEQ ID NO:4 (see Table 2).


In some embodiments, a provided transmembrane immunomodulatory protein that is or comprises a variant PD-L2 comprises a sequence of amino acids that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% sequence identity to SEQ ID NO: 216 and contains an ectodomain comprising at least one affinity-modified PD-L2 IgSF domain as described and a transmembrane domain. In some embodiments, the transmembrane immunomodulatory protein contains any one or more amino acid substitutions in an IgSF domain (e.g. IgV domain) as described, including any set forth in Table 1. In some embodiments, the transmembrane immunomodulatory protein can further comprise a cytoplasmic domain as described. In some embodiments, the transmembrane immunomodulatory protein can further contain a signal peptide. In some embodiments, the signal peptide is the native signal peptide of wild-type IgSF member, such as contained in the sequence of amino acids set forth in SEQ ID NO:4 (see e.g. Table 2).


Also provided is a nucleic acid molecule encoding such transmembrane immunomodulatory proteins. In some embodiments, a nucleic acid molecule encoding a transmembrane immunomodulatory protein comprises a nucleotide sequence that encodes a sequence of amino acids that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% sequence identity to SEQ ID NOS: 216 and contains an ectodomain comprising at least one affinity-modified IgSF domain as described, a transmembrane domain and, optionally, a cytoplasmic domain. In some embodiments, the nucleic acid molecule can further comprise a sequence of nucleotides encoding a signal peptide. In some embodiments, the signal peptide is the native signal peptide of the corresponding wild-type IgSF member (see e.g. Table 2).


In some embodiments, provided are CAR-related transmembrane immunomodulatory proteins in which the endodomain of a transmembrane immunomodulatory protein comprises a cytoplasmic signaling domain that comprises at least one ITAM (immunoreceptor tyrosine-based activation motif)-containing signaling domain. ITAM is a conserved motif found in a number of protein signaling domains involved in signal transduction of immune cells, including in the CD3-zeta chain (“CD3-z”) involved in T-cell receptor signal transduction. In some embodiments, the endodomain comprises at CD3-zeta signaling domain. In some embodiments, the CD3-zeta signaling domain comprises the sequence of amino acids set forth in SEQ ID NO: 243 or a sequence of amino acids that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% to SEQ ID NO:243 and retains the activity of T cell signaling. In some embodiments, the endodomain of a CAR-related transmembrane immunomodulatory protein can further comprise a costimulatory signaling domain to further modulate immunomodulatory responses of the T-cell. In some embodiments, the costimulatory signaling domain is CD28, ICOS, 41BB or OX40. In some embodiments, the costimulatory signaling domain is a derived from CD28 or 4-1BB and comprises the sequence of amino acids set forth in any of SEQ ID NOS: 1213-1216 or a sequence of amino acids that exhibits at least 85%, 86%, 8′7%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% to SEQ ID NO:1213-1216 and retains the activity of T cell costimulatory signaling. In some embodiments, the provided CAR-related transmembrane immunomodulatory proteins have features of CARs to stimulate T cell signaling upon binding of an affinity modified IgSF domain to a cognate binding partner or counter structure. In some embodiments, upon specific binding by the affinity-modified IgSF domain to its counter structure can lead to changes in the immunological activity of the T-cell activity as reflected by changes in cytotoxicity, proliferation or cytokine production.


In some embodiments, the transmembrane immunomodulatory protein does not contain an endodomain capable of mediating cytoplasmic signaling. In some embodiments, the transmembrane immunomodulatory protein lacks the signal transduction mechanism of the wild-type or unmodified polypeptide and therefore does not itself induce cell signaling. In some embodiments, the transmembrane immunomodulatory protein lacks an intracellular (cytoplasmic) domain or a portion of the intracellular domain of the corresponding wild-type or unmodified polypeptide, such as a cytoplasmic signaling domain contained in the sequence of amino acids set forth in SEQ ID NO:4 (see Table 2). In some embodiments, the transmembrane immunomodulatory protein does not contain an ITIM (immunoreceptor tyrosine-based inhibition motif), such as contained in certain inhibitory receptors, including inhibitory receptors of the IgSF family (e.g. PD-1 or TIGIT). Thus, in some embodiments, the transmembrane immunomodulatory protein only contains the ectodomain and the transmembrane domain, such as any as described.


2. Secreted Immunomodulatory Proteins and Engineered Cells


In some embodiments, the PD-L2 variant immunomodulatory polypeptide containing any one or more of the amino acid mutations as described herein, is secretable, such as when expressed from a cell. Such a variant PD-L2 immunomodulatory protein does not comprise a transmembrane domain. In some embodiments, the variant PD-L2 immunomodulatory protein is not conjugated to a half-life extending moiety (such as an Fc domain or a multimerization domain). In some embodiments, the variant PD-L2 immunomodulatory protein comprises a signal peptide, e.g. an antibody signal peptide or other efficient signal sequence to get domains outside of cell. When the immunomodulatory protein comprises a signal peptide and is expressed by an engineered cell, the signal peptide causes the immunomodulatory protein to be secreted by the engineered cell. Generally, the signal peptide, or a portion of the signal peptide, is cleaved from the immunomodulatory protein with secretion. The immunomodulatory protein can be encoded by a nucleic acid (which can be part of an expression vector). In some embodiments, the immunomodulatory protein is expressed and secreted by a cell (such as an immune cell, for example a primary immune cell).


Thus, in some embodiments, there are provided variant PD-L2 immunomodulatory proteins that further comprises a signal peptide. In some embodiments, provided herein is a nucleic acid molecule encoding the variant PD-L2 immunomodulatory protein operably connected to a secretion sequence encoding the signal peptide.


A signal peptide is a sequence on the N-terminus of an immunomodulatory protein that signals secretion of the immunomodulatory protein from a cell. In some embodiments, the signal peptide is about 5 to about 40 amino acids in length (such as about 5 to about 7, about 7 to about 10, about 10 to about 15, about 15 to about 20, about 20 to about 25, or about 25 to about 30, about 30 to about 35, or about 35 to about 40 amino acids in length).


In some embodiments, the signal peptide is a native signal peptide from the corresponding wild-type PD-L2 (see Table 2). In some embodiments, the signal peptide is a non-native signal peptide. For example, in some embodiments, the non-native signal peptide is a mutant native signal peptide from the corresponding wild-type PD-L2, and can include one or more (such as 2, 3, 4, 5, 6, 7, 8, 9, or 10 or more) substitutions insertions or deletions. In some embodiments, the non-native signal peptide is a signal peptide or mutant thereof of a family member from the same IgSF family as the wild-type IgSF family member. In some embodiments, the non-native signal peptide is a signal peptide or mutant thereof from an IgSF family member from a different IgSF family that the wild-type IgSF family member. In some embodiments, the signal peptide is a signal peptide or mutant thereof from a non-IgSF protein family, such as a signal peptide from an immunoglobulin (such as IgG heavy chain or IgG-kappa light chain), a cytokine (such as interleukin-2 (IL-2), or CD33), a serum albumin protein (e.g. HSA or albumin), a human azurocidin preprotein signal sequence, a luciferase, a trypsinogen (e.g. chymotrypsinogen or trypsinogen) or other signal peptide able to efficiently secrete a protein from a cell. Exemplary signal peptides include any described in the Table 9.









TABLE 9







Exemplary Signal Peptides









SEQ ID NO
Signal Peptide
Peptide Sequence





SEQ ID NO: 245
HSA signal peptide
MKWVTFISLLFLFSSAYS





SEQ ID NO: 246
Ig kappa light chain
MDMRAPAGIFGFLLVLFPGYRS





SEQ ID NO: 247
human azurocidin preprotein signal sequence
MTRLTVLALLAGLLASSRA





SEQ ID NO: 248
IgG heavy chain signal peptide
MELGLSWIFLLAILKGVQC





SEQ ID NO: 249
IgG heavy chain signal peptide
MELGLRWVFLVAILEGVQC





SEQ ID NO: 250
IgG heavy chain signal peptide
MKHLWFFLLLVAAPRWVLS





SEQ ID NO: 251
IgG heavy chain signal peptide
MDWTWRILFLVAAATGAHS





SEQ ID NO: 252
IgG heavy chain signal peptide
MDWTWRFLFVVAAATGVQS





SEQ ID NO: 253
IgG heavy chain signal peptide
MEFGLSWLFLVAILKGVQC





SEQ ID NO: 254
IgG heavy chain signal peptide
MEFGLSWVFLVALFRGVQC





SEQ ID NO: 255
IgG heavy chain signal peptide
MDLLHKNMKHLWFFLLLVAAPRWVLS





SEQ ID NO: 256
IgG Kappa light chain signal sequences:
MDMRVPAQLLGLLLLWLSGARC





SEQ ID NO: 257
IgG Kappa light chain signal sequences:
MKYLLPTAAAGLLLLAAQPAMA





SEQ ID NO: 258
Gaussia luciferase
MGVKVLFALICIAVAEA





SEQ ED NO: 259
Human albumin
MKWVTFISLLFLFSSAYS





SEQ ED NO: 260
Human chymotlypsinogen
MAFLWLLSCWALLGTTFG





SEQ ED NO: 261
Human interleukin-2
MQLLSCIALILALV





SEQ ED NO: 262
Human trypsinogen-2
MNLLLILTFVAAAVA









In some embodiments of a secretable variant PD-L2 immunomodulatory protein, the immunomodulatory protein comprises a signal peptide when expressed, and the signal peptide (or a portion thereof) is cleaved from the immunomodulatory protein upon secretion.


In some embodiments, the engineered cells express a variant PD-L2 polypeptides that are secreted from the cell. In some embodiments, such a variant PD-L2 polypeptide is encoded by a nucleic acid molecule encoding an immunomodulatory protein under the operable control of a signal sequence for secretion. In some embodiments, the encoded immunomodulatory protein is secreted when expressed from a cell. In some embodiments, the immunomodulatory protein encoded by the nucleic acid molecule does not comprise a transmembrane domain. In some embodiments, the immunomodulatory protein encoded by the nucleic acid molecule does not comprise a half-life extending moiety (such as an Fc domain or a multimerization domain). In some embodiments, the immunomodulatory protein encoded by the nucleic acid molecule comprises a signal peptide. In some embodiments, a nucleic acid of the invention further comprises nucleotide sequence that encodes a secretory or signal peptide operably linked to the nucleic acid encoding the immunomodulatory protein, thereby allowing for secretion of the immunomodulatory protein


3. Cells and Engineering Cells


Provided herein are engineered cells expressing any of the provided immunomodulatory polypeptides. In some embodiments, the engineered cells express on their surface any of the provided transmembrane immunomodulatory polypeptides. In some embodiments, the engineered cells express and are capable of or are able to secrete the immunomodulatory protein from the cells under conditions suitable for secretion of the protein. In some embodiments, the immunomodulatory protein is expressed on or in a lymphocyte such as a tumor infiltrating lymphocyte (TIL), T-cell or NK cell, or on a myeloid cell. In some embodiments, the engineered cells are antigen presenting cells (APCs). In some embodiments, the engineered cells are engineered mammalian T-cells or engineered mammalian antigen presenting cells (APCs). In some embodiments, the engineered T-cells or APCs are human or murine cells.


In some embodiments, engineered T-cells include, but are not limited to, T helper cell, cytotoxic T-cell (alternatively, cytotoxic T lymphocyte or CTL), natural killer T-cell, regulatory T-cell, memory T-cell, or gamma delta T-cell. In some embodiments, the engineered T cells are CD4+ or CD8+.


In some embodiments, the engineered APCs include, for example, MHC II expressing APCs such as macrophages, B cells, and dendritic cells, as well as artificial APCs (aAPCs) including both cellular and acellular (e.g., biodegradable polymeric microparticles) aAPCs. Artificial APCs (aAPCs) are synthetic versions of APCs that can act in a similar manner to APCs in that they present antigens to T-cells as well as activate them. Antigen presentation is performed by the MHC (Class I or Class II). In some embodiments, in engineered APCs such as aAPCs, the antigen that is loaded onto the MHC is, in some embodiments, a tumor specific antigen or a tumor associated antigen. The antigen loaded onto the MHC is recognized by a T-cell receptor (TCR) of a T cell, which, in some cases, can express PD-1 or other molecule recognized by the variant PD-L2 polypeptides provided herein. Materials which can be used to engineer an aAPC include: poly (glycolic acid), poly(lactic-co-glycolic acid), iron-oxide, liposomes, lipid bilayers, sepharose, and polystyrene.


In some embodiments a cellular aAPC can be engineered to contain a TIP and TCR agonist which is used in adoptive cellular therapy. In some embodiments, a cellular aAPC can be engineered to contain a TIP and TCR agonist which is used in ex vivo expansion of human T cells, such as prior to administration, e.g. for reintroduction into the patient. In some aspects, the aAPC may include expression of at least one anti-CD3 antibody clone, e.g. such as, for example, OKT3 and/or UCHT1. In some aspects, the aAPCs may be inactivated (e.g. irradiated). In some embodiment, the TIP can include any variant IgSF domain that exhibits binding affinity for a cognate binding partner on a T cell.


In some embodiments, an immunomodulatory protein provided herein, such as a transmembrane immunomodulatory protein or a secretable immunomodulatory protein, is co-expressed or engineered into a cell that expresses an antigen-binding receptor, such as a recombinant receptor, such as a chimeric antigen receptor (CAR) or T cell receptor (TCR). In some embodiments, the engineered cell, such as an engineered T cell, recognizes a desired antigen associated with cancer, inflammatory and autoimmune disorders, or a viral infection. In specific embodiments, the antigen-binding receptor contains an antigen-binding moiety that specifically binds a tumor specific antigen or a tumor associated antigen. In some embodiments, the engineered T-cell is a CAR (chimeric antigen receptor) T-cell that contains an antigen-binding domain (e.g. scFv) that specifically binds to an antigen, such as a tumor specific antigen or tumor associated antigen. In some embodiments, the TIP protein is expressed in an engineered T-cell receptor cell or an engineered chimeric antigen receptor cell. In such embodiments, the engineered cell co-expresses the TIP and the CAR or TCR. In some embodiments, the SIP protein is expressed in an engineered T-cell receptor cell or an engineered chimeric antigen receptor cell. In such embodiments, the engineered cell co-expresses the SIP and the CAR or TCR.


In some embodiments, the SIP protein is expressed in an engineered T-cell receptor cell or an engineered chimeric antigen receptor cell. In such embodiments, the engineered cell co-expresses the SIP and the CAR or TCR.


Chimeric antigen receptors (CARs) are recombinant receptors that include an antigen-binding domain (ectodomain), a transmembrane domain and an intracellular signaling region (endodomain) that is capable of inducing or mediating an activation signal to the T cell after the antigen is bound. In some example, CAR-expressing cells are engineered to express an extracellular single chain variable fragment (scFv) with specificity for a particular tumor antigen linked to an intracellular signaling part comprising an activating domain and, in some cases, a costimulatory domain. The costimulatory domain can be derived from, e.g., CD28, OX-40, 4-1BB/CD137, inducible T cell costimulator (ICOS), The activating domain can be derived from, e.g., CD3, such as CD3 zeta, epsilon, delta, gamma, or the like. In certain embodiments, the CAR is designed to have two, three, four, or more costimulatory domains. The CAR scFv can be designed to target an antigen exressed on a cell associated with a disease or condition, e.g. a tumor antigen, such as, for example, CD19, which is a transmembrane protein expressed by cells in the B cell lineage, including all normal B cells and B cell malignances, including but not limited to NHL, CLL, and non-T cell ALL. Example CAR+ T cell therapies and constructs are described in U.S. Patent Publication Nos. 2013/0287748, 2014/0227237, 2014/0099309, and 2014/0050708, and these references are incorporated by reference in their entirety.


In some aspects, the antigen-binding domain is an antibody or antigen-binding fragment thereof, such as a single chain fragment (scFv). In some embodiments, the antigen is expressed on a tumor or cancer cell. Exemplary of an antigen is CD19. Exemplary of a CAR is an anti-CD19 CAR, such as a CAR containing an anti-CD19 scFv set forth in SEQ ID NO:1163 or SEQ ID NO:1174. In some embodiments, the CAR further contains a spacer, a transmembrane domain, and an intracellular signaling domain or region comprising an ITAM signaling domain, such as a CD3zeta signaling domain. In some embodiments, the CAR further includes a costimulatory signaling domain. In some embodiments, the spacer and transmembrane domain are the hinge and transmembrane domain derived from CD8, such as having an exemplary sequence set forth in SEQ ID NO: 266, 1212, 2022 or a sequence of amino acids that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to SEQ ID NO:266, 1212, 2022. In some embodiments, the endodomain comprises at CD3-zeta signaling domain. In some embodiments, the CD3-zeta signaling domain comprises the sequence of amino acids set forth in SEQ ID NO: 243 or a sequence of amino acids that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% or more sequence identity to SEQ ID NO:243 and retains the activity of T cell signaling. In some embodiments, the endodomain of a CAR can further comprise a costimulatory signaling domain or region to further modulate immunomodulatory responses of the T-cell. In some embodiments, the costimulatory signaling domain is or comprises a costimulatory region, or is derived from a costimulatory region, of CD28, ICOS, 41BB or OX40. In some embodiments, the costimulatory signaling domain is a derived from CD28 or 4-1BB and comprises the sequence of amino acids set forth in any of SEQ ID NOS: 1213-1216 or a sequence of amino acids that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% or more sequence identity to SEQ ID NO: 1213-1216 and retains the activity of T cell costimulatory signaling.


In some embodiments, the construct encoding the CAR further encodes a second protein, such as a marker, e.g. detectable protein, separated from the CAR by a self-cleaving peptide sequence. In some embodiments, the self-cleaving peptide sequence is an F2A, T2A, E2A or P2A self-cleaving peptide. Exemplary sequences of a T2A self-cleaving peptide are set for the in any one of SEQ ID NOS: 1217, 1225 or 2029 or a sequence of amino acids that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% or more sequence identity to any of SEQ ID NOS: 1217, 1225 or 2029. In some embodiments, the T2A is encoded by the sequence of nucleotides set forth in SEQ ID NO:1255 or a sequence that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% or more sequence identity to any of SEQ ID NO: 1255. An exemplary sequence of a P2A self-cleaving peptide is set in SEQ ID NO: 2038 or a sequence of amino acids that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% or more sequence identity to SEQ ID NOS: 2038. In some cases, a nucleic acid construct that encodes more than one P2A self-cleaving peptide (such as a P2A1 and P2A2), in which the nucleotide sequence P2A1 and P2A2 each encode the P2A set forth in SEQ ID NO:2038, the nucleotide sequence may be different to avoid recombination between sequences.


In some embodiments, the marker is a detectable protein, such as a fluorescent protein, e.g. a green fluorescent protein (GFP) or blue fluorescent protein (BFP). Exemplary sequences of a fluorescent protein marker are set forth in SEQ ID NO:1218, 2028, or 2035-2037 or a sequence of amino acids that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% or more sequence identity to SEQ ID NO: 1218, 2028, or 2035-2037.


In some embodiments, the CAR has the sequence of amino acids set forth in any of SEQ ID NOS: 1208, 1219, 1220, 1221, 2023, 2024, 2026 or 2027 or a sequence of amino acids that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% or more sequence identity to any one of SEQ ID NOS: 1208, 1219, 1220, 1221, 2023, 2024, 2026 or 2027. In some embodiments, the CAR is encoded by a sequence of nucleotides set forth in SEQ ID NO: 1223 or 2025 or a sequence of amino acids that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% or more sequence identity to any one of SEQ ID NO: 1223 or 2025.


In another embodiment, the engineered T-cell possesses a TCR, including a recombinant or engineered TCR. In some embodiments, the TCR can be a native TCR. Those of skill in the art will recognize that generally native mammalian T-cell receptors comprise an alpha and a beta chain (or a gamma and a delta chain) involved in antigen specific recognition and binding. In some embodiments, the TCR is an engineered TCR that is modified. In some embodiments, the TCR of an engineered T-cell specifically binds to a tumor associated or tumor specific antigen presented by an APC.


In some embodiments, the immunomodulatory polypeptides, such as transmembrane immunomodulatory polypeptides or secretable immunomodulatory polypeptides, can be incorporated into engineered cells, such as engineered T cells or engineered APCs, by a variety of strategies such as those employed for recombinant host cells. A variety of methods to introduce a DNA construct into primary T cells are known in the art. In some embodiments, viral transduction or plasmid electroporation are employed. In typical embodiments, the nucleic acid molecule encoding the immunomodulatory protein, or the expression vector, comprises a signal peptide that localizes the expressed transmembrane immunomodulatory proteins to the cellular membrane or for secretion. In some embodiments, a nucleic acid encoding a transmembrane immunomodulatory proteins of the invention is sub-cloned into a viral vector, such as a retroviral vector, which allows expression in the host mammalian cell. The expression vector can be introduced into a mammalian host cell and, under host cell culture conditions, the immunomodulatory protein is expressed on the surface or is secreted.


In an exemplary example, primary T-cells can be purified ex vivo (CD4 cells or CD8 cells or both) and stimulated with an activation protocol consisting of various TCR/CD28 agonists, such as anti-CD3/anti-CD28 coated beads. After a 2 or 3 day activation process, a recombinant expression vector containing an immunomodulatory polypeptide can be stably introduced into the primary T cells through art standard lentiviral or retroviral transduction protocols or plasmid electroporation strategies. Cells can be monitored for immunomodulatory polypeptide expression by, for example, flow cytometry using anti-epitope tag or antibodies that cross-react with native parental molecule and polypeptides comprising variant PD-L2. T-cells that express the immunomodulatory polypeptide can be enriched through sorting with anti-epitope tag antibodies or enriched for high or low expression depending on the application.


Upon immunomodulatory polypeptide expression the engineered T-cell can be assayed for appropriate function by a variety of means. The engineered CAR or TCR co-expression can be validated to show that this part of the engineered T cell was not significantly impacted by the expression of the immunomodulatory protein. Once validated, standard in vitro cytotoxicity, proliferation, or cytokine assays (e.g., IFN-gamma expression) can be used to assess the function of engineered T-cells. Exemplary standard endpoints are percent lysis of the tumor line, proliferation of the engineered T-cell, or IFN-gamma protein expression in culture supernatants. An engineered construct which results in statistically significant increased lysis of tumor line, increased proliferation of the engineered T-cell, or increased IFN-gamma expression over the control construct can be selected for. Additionally, non-engineered, such as native primary or endogenous T-cells could also be incorporated into the same in vitro assay to measure the ability of the immunomodulatory polypeptide construct expressed on the engineered cells, such as engineered T-cells, to modulate activity, including, in some cases, to activate and generate effector function in bystander, native T-cells. Increased expression of activation markers such as CD69, CD44, or CD62L could be monitored on endogenous T cells, and increased proliferation and/or cytokine production could indicate desired activity of the immunomodulatory protein expressed on the engineered T cells.


In some embodiments, the similar assays can be used to compare the function of engineered T cells containing the CAR or TCR alone to those containing the CAR or TCR and a TIP construct. Typically, these in vitro assays are performed by plating various ratios of the engineered T cell and a “tumor” cell line containing the cognate CAR or TCR antigen together in culture. Standard endpoints are percent lysis of the tumor line, proliferation of the engineered T cell, or IFN-gamma production in culture supernatants. An engineered immunomodulatory protein which resulted in statistically significant increased lysis of tumor line, increased proliferation of the engineered T cell, or increased IFN-gamma production over the same TCR or CAR construct alone can be selected for. Engineered human T cells can be analyzed in immunocompromised mice, like the NSG strain, which lacks mouse T, NK and B cells. Engineered human T cells in which the CAR or TCR binds a target counter-structure on the xenograft and is co-expressed with the TIP affinity modified IgSF domain can be adoptively transferred in vivo at different cell numbers and ratios compared to the xenograft. For example, engraftment of CD19+ leukemia tumor lines containing a luciferase/GFP vector can be monitored through bioluminescence or ex vivo by flow cytometry. In a common embodiment, the xenograft is introduced into the murine model, followed by the engineered T cells several days later. Engineered T cells containing the immunomodulatory protein can be assayed for increased survival, tumor clearance, or expanded engineered T cells numbers relative to engineered T cells containing the CAR or TCR alone. As in the in vitro assay, endogenous, native (i.e., non-engineered) human T cells could be co-adoptively transferred to look for successful epitope spreading in that population, resulting in better survival or tumor clearance.


E. Infectious Agents Expressing Variant Polypeptides and Immunomodulatory Proteins


Also provided are infectious agents that contain nucleic acids encoding any of the variant polypeptides, such as PD-L2 vIgD polypeptides, including secretable or transmembrane immunomodulatory proteins described herein. In some embodiments, such infectious agents can deliver the nucleic acids encoding the variant immunomodulatory polypeptides described herein, such as PD-L2 vIgD polypeptides, to a target cell in a subject, e.g., immune cell and/or antigen-presenting cell (APC) or tumor cell in a subject. Also provided are nucleic acids contained in such infectious agents, and/or nucleic acids for generation or modification of such infectious agents, such as vectors and/or plasmids, and compositions containing such infectious agents.


In some embodiments, the infectious agent is a microorganism or a microbe. In some embodiments, the infectious agent is a virus or a bacterium. In some embodiments, the infectious agent is a virus. In some embodiments, the infectious agent is a bacterium. In some embodiments, such infectious agents can deliver nucleic acid sequences encoding any of the variant polypeptides, such as PD-L2 vIgD polypeptides, including secretable or transmembrane immunomodulatory proteins, described herein. Thus, in some embodiments, the cell in a subject that is infected or contacted by the infectious agents can be rendered to express on the cell surface or secrete, the variant immunomodulatory polypeptides. In some embodiments, the infectious agent can also deliver one or more other therapeutics or nucleic acids encoding other therapeutics to the cell and/or to an environment within the subject. In some embodiments, other therapeutics that can be delivered by the infectious agents include cytokines or other immunomodulatory molecules.


In some embodiments, the infectious agent, e.g., virus or bacteria, contains nucleic acid sequences that encode any of the variant polypeptides, such as PD-L2 vIgD polypeptides, including secretable or transmembrane immunomodulatory proteins, described herein, and by virtue of contact and/or infection of a cell in the subject, the cell expresses the variant polypeptides, such as PD-L2 vIgD polypeptides, including secretable or transmembrane immunomodulatory proteins, encoded by the nucleic acid sequences contained in the infectious agent. In some embodiments, the infectious agent can be administered to the subject. In some embodiments, the infectious agent can be contacted with cells from the subject ex vivo.


In some embodiments, the variant polypeptides, such as PD-L2 vIgD polypeptides, including transmembrane immunomodulatory proteins, expressed by the cell infected by the infectious agent is a transmembrane protein and is surface expressed. In some embodiments, the variant polypeptides, such as PD-L2 vIgD polypeptides, including secretable immunomodulatory proteins, expressed by the cell infected by the infectious agent is expressed and secreted from the cell. The transmembrane immunomodulatory protein or secreted immunomodulatory protein can be any described herein.


In some embodiments, the cells in the subject that are targeted by the infectious agent include a tumor cell, an immune cell, and/or an antigen-presenting cell (APC). In some embodiments, the infectious agent targets a cell in the tumor microenvironment (TME). In some embodiments, the infectious agent delivers the nucleic acids encoding the variant polypeptides, such as PD-L2 vIgD polypeptides, including secretable or transmembrane immunomodulatory proteins, to an appropriate cell (for example, an APC, such as a cell that displays a peptide/WIC complex on its cell surface, such as a dendritic cell) or tissue (e.g., lymphoid tissue) that will induce and/or augment the desired effect, e.g., immunomodulation and/or a specific cell-medicated immune response, e.g., CD4 and/or CD8 T cell response, which CD8 T cell response may include a cytotoxic T cell (CTL) response. In some embodiments, the infectious agent targets an APC, such as a dendritic cell (DC). In some embodiments, the nucleic acid molecule delivered by the infectious agents described herein include appropriate nucleic acid sequences necessary for the expression of the operably linked coding sequences encoding the variant immunomodulatory polypeptides, in a particular target cell, e.g., regulatory elements such as promoters.


In some embodiments, the infectious agent that contains nucleic acid sequences encoding the immunomodulatory polypeptides can also contain nucleic acid sequences that encode one or more additional gene products, e.g., cytokines, prodrug converting enzymes, cytotoxins and/or detectable gene products. For example, in some embodiments, the infectious agent is an oncolytic virus and the virus can include nucleic acid sequences encoding additional therapeutic gene products (see, e.g., Kim et al., (2009) Nat Rev Cancer 9:64-71; Garcia-Aragoncillo et al., (2010) Curr Opin Mol Ther 12:403-411; see U.S. Pat. Nos. 7,588,767, 7,588,771, 7,662,398 and 7,754,221 and U.S. Pat. Publ. Nos. 2007/0202572, 2007/0212727, 2010/0062016, 2009/0098529, 2009/0053244, 2009/0155287, 2009/0117034, 2010/0233078, 2009/0162288, 2010/0196325, 2009/0136917 and 2011/0064650. In some embodiments, the additional gene product can be a therapeutic gene product that can result in death of the target cell (e.g., tumor cell) or gene products that can augment or boost or regulate an immune response (e.g., cytokine). Exemplary gene products also include among an anticancer agent, an anti-metastatic agent, an antiangiogenic agent, an immunomodulatory molecule, an immune checkpoint inhibitor, an antibody, a cytokine, a growth factor, an antigen, a cytotoxic gene product, a pro-apoptotic gene product, an anti-apoptotic gene product, a cell matrix degradative gene, genes for tissue regeneration and reprogramming human somatic cells to pluripotency, and other genes described herein or known to one of skill in the art. In some embodiments, the additional gene product is Granulocyte-macrophage colony-stimulating factor (GM-CSF).


1. Viruses


In some embodiments, the infectious agent is a virus. In some embodiments, the infectious agent is an oncolytic virus, or a virus that targets particular cells, e.g., immune cells. In some embodiments, the infectious agent targets a tumor cell and/or cancer cell in the subject. In some embodiments, the infectious agent targets an immune cell or an antigen-presenting cell (APC).


In some embodiments, the infectious agent is an oncolytic virus. Oncolytic viruses are viruses that accumulate in tumor cells and replicate in tumor cells. By virtue of replication in the cells, and optional delivery of nucleic acids encoding variant PD-L2 polypeptides or immunomodulatory polypeptides described herein, tumor cells are lysed, and the tumor shrinks and can be eliminated. Oncolytic viruses can also have a broad host and cell type range. For example, oncolytic viruses can accumulate in immunoprivileged cells or immunoprivileged tissues, including tumors and/or metastases, and also including wounded tissues and cells, thus allowing the delivery and expression of nucleic acids encoding the variant immunomodulatory polypeptides described herein in a broad range of cell types. Oncolytic viruses can also replicate in a tumor cell specific manner, resulting in tumor cell lysis and efficient tumor regression.


Exemplary oncolytic viruses include adenoviruses, adeno-associated viruses, herpes viruses, Herpes Simplex Virus, vesticular stomatic virus, Reovirus, Newcastle Disease virus, parvovirus, measles virus, vesticular stomatitis virus (VSV), Coxsackie virus and Vaccinia virus. In some embodiments, oncolytic viruses can specifically colonize solid tumors, while not infecting other organs, and can be used as an infectious agent to deliver the nucleic acids encoding the variant immunomodulatory polypeptides described herein to such solid tumors.


Oncolytic viruses for use in delivering the nucleic acids encoding variant PD-L2 polypeptides or immunomodulatory polypeptides described herein, can be any of those known to one of skill in the art and include, for example, vesicular stomatitis virus, see, e.g., U.S. Pat. Nos. 7,731,974, 7,153,510, 6,653,103 and U.S. Pat. Pub. Nos. 2010/0178684, 2010/0172877, 2010/0113567, 2007/0098743, 20050260601, 20050220818 and EP Pat. Nos. 1385466, 1606411 and 1520175; herpes simplex virus, see, e.g., U.S. Pat. Nos. 7,897,146, 7,731,952, 7,550,296, 7,537,924, 6,723,316, 6,428,968 and U.S. Pat. Pub. Nos., 2014/0154216, 2011/0177032, 2011/0158948, 2010/0092515, 2009/0274728, 2009/0285860, 2009/0215147, 2009/0010889, 2007/0110720, 2006/0039894, 2004/0009604, 2004/0063094, International Patent Pub. Nos., WO 2007/052029, WO 1999/038955; retroviruses, see, e.g., U.S. Pat. Nos. 6,689,871, 6,635,472, 5,851,529, 5,716,826, 5,716,613 and U.S. Pat. Pub. No. 20110212530; vaccinia viruses, see, e.g., 2016/0339066, and adeno-associated viruses, see, e.g., U.S. Pat. Nos. 8,007,780, 7,968,340, 7,943,374, 7,906,111, 7,927,585, 7,811,814, 7,662,627, 7,241,447, 7,238,526, 7,172,893, 7,033,826, 7,001,765, 6,897,045, and 6,632,670.


Oncolytic viruses also include viruses that have been genetically altered to attenuate their virulence, to improve their safety profile, enhance their tumor specificity, and they have also been equipped with additional genes, for example cytotoxins, cytokines, prodrug converting enzymes to improve the overall efficacy of the viruses (see, e.g., Kim et al., (2009) Nat Rev Cancer 9:64-71; Garcia-Aragoncillo et al., (2010) Curr Opin Mol Ther 12:403-411; see U.S. Pat. Nos. 7,588,767, 7,588,771, 7,662,398 and 7,754,221 and U.S. Pat. Publ. Nos. 2007/0202572, 2007/0212727, 2010/0062016, 2009/0098529, 2009/0053244, 2009/0155287, 2009/0117034, 2010/0233078, 2009/0162288, 2010/0196325, 2009/0136917 and 2011/0064650). In some embodiments, the oncolytic viruses can be those that have been modified so that they selectively replicate in cancerous cells, and, thus, are oncolytic. For example, the oncolytic virus is an adenovirus that has been engineered to have modified tropism for tumor therapy and also as gene therapy vectors. Exemplary of such is ONYX-015, H101 and Ad5ΔCR (Hallden and Portella (2012) Expert Opin Ther Targets, 16:945-58) and TNFerade (McLoughlin et al. (2005) Ann. Surg. Oncol., 12:825-30), or a conditionally replicative adenovirus Oncorine®.


In some embodiments, the infectious agent is a modified herpes simplex virus. In some embodiments, the infectious agent is a modified version of Talimogene laherparepvec (also known as T-Vec, Imlygic or OncoVex GM-CSF), that is modified to contain nucleic acids encoding any of the variant immunomodulatory polypeptides described herein, such as variant PD-L2 or immunomodulatory polypeptides described herein. In some embodiments, the infectious agent is a modified herpes simplex virus that is described, e.g., in WO 2007/052029, WO 1999/038955, US 2004/0063094, US 2014/0154216, or, variants thereof.


In some embodiments, the infectious agent is a virus that targets a particular type of cells in a subject that is administered the virus, e.g., a virus that targets immune cells or antigen-presenting cells (APCs). Dendritic cells (DCs) are essential APCs for the initiation and control of immune responses. DCs can capture and process antigens, migrate from the periphery to a lymphoid organ, and present the antigens to resting T cells in a major histocompatibility complex (MHC)-restricted fashion. In some embodiments, the infectious agent is a virus that specifically can target DCs to deliver nucleic acids encoding the variant PD-L2 polypeptides or immunomodulatory polypeptides for expression in DCs. In some embodiments, the virus is a lentivirus or a variant or derivative thereof, such as an integration-deficient lentiviral vector. In some embodiments, the virus is a lentivirus that is pseudotyped to efficiently bind to and productively infect cells expressing the cell surface marker dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN), such as DCs. In some embodiments, the virus is a lentivirus pseudotyped with a Sindbis virus E2 glycoprotein or modified form thereof, such as those described in WO 2013/149167. In some embodiments, the virus allows for delivery and expression of a sequence of interest (e.g., a nucleic acid encoding any of the variant PD-L2 polypeptides or immunomodulatory polypeptides described herein) to a DC. In some embodiments, the virus includes those described in WO 2008/011636 or US 2011/0064763, Tareen et al. (2014) Mol. Ther., 22:575-587, or variants thereof. Exemplary of a dendritic cell-tropic vector platform is ZVex™.


2. Bacteria


In some embodiments, the infectious agent is a bacterium. For example, in some embodiments, the bacteria can deliver nucleic acids encoding any of the variant PD-L2 polypeptides or immunomodulatory polypeptides described herein to a target cell in the subject, such as a tumor cell, an immune cell, an antigen-presenting cell and/or a phagocytic cell. In some embodiments, the bacterium can be preferentially targeted to a specific environment within a subject, such as a tumor microenvironment (TME), for expression and/or secretion of the variant immunomodulatory polypeptides and/or to target specific cells in the environment for expression of the variant immunomodulatory polypeptides.


In some embodiments, the bacterium delivers the nucleic acids to the cells via bacterial-mediated transfer of plasmid DNA to mammalian cells (also referred to as “bactofection”). For example, in some embodiments, delivery of genetic material is achieved through entry of the entire bacterium into target cells. In some embodiments, spontaneous or induced bacterial lysis can lead to the release of plasmid for subsequent eukaryotic cell expression. In some embodiments, the bacterium can deliver nucleic acids to non-phagocytic mammalian cells (e.g., tumor cells) and/or to phagocytic cells, e.g., certain immune cells and/or APCs. In some embodiments, the nucleic acids delivered by the bacterium can be transferred to the nucleus of the cell in the subject for expression. In some embodiments, the nucleic acids also include appropriate nucleic acid sequences necessary for the expression of the operably linked sequences encoding the variant immunomodulatory polypeptides in a particular host cell, e.g., regulatory elements such as promoters or enhancers. In some embodiments, the infectious agent that is a bacterium can deliver nucleic acids encoding the immunomodulatory proteins in the form of an RNA, such as a pre-made translation-competent RNA delivered to the cytoplasm of the target cell for translation by the target cell's machinery.


In some embodiments, the bacterium can replicate and lyse the target cells, e.g., tumor cells. In some embodiments, the bacterium can contain and/or release nucleic acid sequences and/or gene products in the cytoplasm of the target cells, thereby killing the target cell, e.g., tumor cell. In some embodiments, the infectious agent is bacterium that can replicate specifically in a particular environment in the subject, e.g., tumor microenvironment (TME). For example, in some embodiments, the bacterium can replicate specifically in anaerobic or hypoxic microenvironments. In some embodiments, conditions or factors present in particular environments, e.g., aspartate, serine, citrate, ribose or galactose produced by cells in the TME, can act as chemoattractants to attract the bacterium to the environment. In some embodiments, the bacterium can express and/or secrete the immunomodulatory proteins described herein in the environment, e.g., TME.


In some embodiments, the infectious agent is a bacterium that is a Listeria sp., a Bifidobacterium sp., an Escherichia sp., a Closteridium sp., a Salmonella sp., a Shigella sp., a Vibrio sp. or a Yersinia sp. In some embodiments, the bacterium is selected from among one or more of Listeria monocytogenes, Salmonella typhimurium, Salmonella choleraesuis, Escherichia coli, Vibrio cholera, Clostridium perfringens, Clostridium butyricum, Clostridium novyi, Clostridium acetobutylicum, Bifidobacterium infantis, Bifidobacterium longum and Bifidobacterium adolescentis. In some embodiments, the bacterium is an engineered bacterium. In some embodiments, the bacterium is an engineered bacterium such as those described in, e.g., Seow and Wood (2009) Molecular Therapy 17(5):767-777; Baban et al. (2010) Bioengineered Bugs 1:6, 385-394; Patyar et al. (2010) J Biomed Sci 17:21; Tangney et al. (2010) Bioengineered Bugs 1:4, 284-287; van Pijkeren et al. (2010) Hum Gene Ther. 21(4):405-416; WO 2012/149364; WO 2014/198002; U.S. Pat. Nos. 9,103,831; 9,453,227; US 2014/0186401; US 2004/0146488; US 2011/0293705; US 2015/0359909 and EP 3020816. The bacterium can be modified to deliver nucleic acid sequences encoding any of the variant immunomodulatory polypeptides, conjugates and/or fusions provided herein, and/or to express such variant immunomodulatory polypeptides in the subject.


F. Nucleic Acids, Vectors and Methods for Producing the Polypeptides or Cells


Provided herein are isolated or recombinant nucleic acids collectively referred to as “nucleic acids” which encode any of the various provided embodiments of the variant PD-L2 polypeptides or immunomodulatory polypeptides provided herein. In some embodiments, nucleic acids provided herein, including all described below, are useful in recombinant production (e.g., expression) of variant PD-L2 polypeptides or immunomodulatory polypeptides provided herein. In some embodiments, nucleic acids provided herein, including all described below, are useful in expression of variant PD-L2 polypeptides or immunomodulatory polypeptides provided herein in cells, such as in engineered cells, e.g. immune cells, or infectious agent cells. The nucleic acids provided herein can be in the form of RNA or in the form of DNA, and include mRNA, cRNA, recombinant or synthetic RNA and DNA, and cDNA. The nucleic acids provided herein are typically DNA molecules, and usually double-stranded DNA molecules. However, single-stranded DNA, single-stranded RNA, double-stranded RNA, and hybrid DNA/RNA nucleic acids or combinations thereof comprising any of the nucleotide sequences of the invention also are provided.


Also provided herein are recombinant expression vectors and recombinant host cells useful in producing the variant PD-L2 polypeptides or immunomodulatory polypeptides provided herein.


Also provided herein are engineered cells, such as engineered immune cells, containing any of the provided nucleic acid molecules or encoded variant PD-L2 polypeptides or immunomodulatory polypeptides, such as any of the transmembrane immunomodulatory polypeptides or secretable immunomodulatory polypeptides.


Also provided herein are infectious agents, such as bacterial or viral cells, containing any of the provided nucleic acid molecules or encoded variant PD-L2 polypeptides or immunomodulatory polypeptides, such as any of the transmembrane immunomodulatory polypeptides or secretable immunomodulatory polypeptides.


In any of the above provided embodiments, the nucleic acids encoding the immunomodulatory polypeptides provided herein can be introduced into cells using recombinant DNA and cloning techniques. To do so, a recombinant DNA molecule encoding a immunomodulatory polypeptide is prepared. Methods of preparing such DNA molecules are well known in the art. For instance, sequences coding for the peptides could be excised from DNA using suitable restriction enzymes. Alternatively, the DNA molecule could be synthesized using chemical synthesis techniques, such as the phosphoramidite method. Also, a combination of these techniques could be used. In some instances, a recombinant or synthetic nucleic acid may be generated through polymerase chain reaction (PCR). In some embodiments, a DNA insert can be generated encoding one or more variant PD-L2 polypeptides containing at least one affinity-modified IgSF domain and, in some embodiments, a signal peptide, a transmembrane domain and/or an endodomain in accord with the provided description. This DNA insert can be cloned into an appropriate transduction/transfection vector as is known to those of skill in the art. Also provided are expression vectors containing the nucleic acid molecules.


In some embodiments, the expression vectors are capable of expressing the immunomodulatory proteins in an appropriate cell under conditions suited to expression of the protein. In some aspects, nucleic acid molecule or an expression vector comprises the DNA molecule that encodes the immunomodulatory protein operatively linked to appropriate expression control sequences. Methods of effecting this operative linking, either before or after the DNA molecule is inserted into the vector, are well known. Expression control sequences include promoters, activators, enhancers, operators, ribosomal binding sites, start signals, stop signals, cap signals, polyadenylation signals, and other signals involved with the control of transcription or translation.


In some embodiments, expression of the immunomodulatory protein is controlled by a promoter or enhancer to control or regulate expression. The promoter is operably linked to the portion of the nucleic acid molecule encoding the variant polypeptide or immunomodulatory protein. In some embodiments, the promotor is a constitutively active promotor (such as a tissue-specific constitutively active promotor or other constitutive promotor). In some embodiments, the promotor is an inducible promotor, which may be responsive to an inducing agent (such as a T cell activation signal).


In some embodiments, a constitutive promoter is operatively linked to the nucleic acid molecule encoding the variant polypeptide or immunomodulatory protein. Exemplary constitutive promoters include the Simian vacuolating virus 40 (SV40) promoter, the cytomegalovirus (CMV) promoter, the ubiquitin C (UbC) promoter, and the EF-1 alpha (EF1a) promoter. In some embodiments, the constitutive promoter is tissue specific. For example, in some embodiments, the promoter allows for constitutive expression of the immunomodulatory protein in specific tissues, such as immune cells, lymphocytes, or T cells. Exemplary tissue-specific promoters are described in U.S. Pat. No. 5,998,205, including, for example, a fetoprotein, DF3, tyrosinase, CEA, surfactant protein, and ErbB2 promoters.


In some embodiments, an inducible promoter is operatively linked to the nucleic acid molecule encoding the variant polypeptide or immunomodulatory protein such that expression of the nucleic acid is controllable by controlling the presence or absence of the appropriate inducer of transcription. For example, the promoter can be a regulated promoter and transcription factor expression system, such as the published tetracycline-regulated systems or other regulatable systems (see, e.g. published International PCT Appl. No. WO 01/30843), to allow regulated expression of the encoded polypeptide. An exemplary regulatable promoter system is the Tet-On (and Tet-Off) system available, for example, from Clontech (Palo Alto, Calif.). This promoter system allows the regulated expression of the transgene controlled by tetracycline or tetracycline derivatives, such as doxycycline. Other regulatable promoter systems are known (see e.g., published U.S. Application No. 2002-0168714, entitled “Regulation of Gene Expression Using Single-Chain, Monomeric, Ligand Dependent Polypeptide Switches,” which describes gene switches that contain ligand binding domains and transcriptional regulating domains, such as those from hormone receptors).


In some embodiments, the promotor is responsive to an element responsive to T-cell activation signaling. Solely by way of example, in some embodiments, an engineered T cell comprises an expression vector encoding the immunomodulatory protein and a promotor operatively linked to control expression of the immunomodulatory protein. The engineered T cell can be activated, for example by signaling through an engineered T cell receptor (TCR) or a chimeric antigen rector (CAR), and thereby triggering expression and secretion of the immunomodulatory protein through the responsive promotor.


In some embodiments, an inducible promoter is operatively linked to the nucleic acid molecule encoding the immunomodulatory protein such that the immunomodulatory protein is expressed in response to a nuclear factor of activated T-cells (NFAT) or nuclear factor kappa-light-chain enhancer of activated B cells (NF-κB). For example, in some embodiments, the inducible promoter comprises a binding site for NFAT or NF-κB. For example, in some embodiments, the promoter is an NFAT or NF-κB promoter or a functional variant thereof. Thus, in some embodiments, the nucleic acids make it possible to control the expression of immunomodulatory protein while also reducing or eliminating the toxicity of the immunomodulatory protein. In particular, engineered immune cells comprising the nucleic acids of the invention express and secrete the immunomodulatory protein only when the cell (e.g., a T-cell receptor (TCR) or a chimeric antigen receptor (CAR) expressed by the cell) is specifically stimulated by an antigen and/or the cell (e.g., the calcium signaling pathway of the cell) is non-specifically stimulated by, e.g., phorbol myristate acetate (PMA)/Ionomycin. Accordingly, the expression and, in some cases, secretion, of immunomodulatory protein can be controlled to occur only when and where it is needed (e.g., in the presence of an infectious disease-causing agent, cancer, or at a tumor site), which can decrease or avoid undesired immunomodulatory protein interactions.


In some embodiments, the nucleic acid encoding an immunomodulatory protein described herein comprises a suitable nucleotide sequence that encodes a NFAT promoter, NF-κB promoter, or a functional variant thereof. “NFAT promoter” as used herein means one or more NFAT responsive elements linked to a minimal promoter. “NF-κB promoter” refers to one or more NF-κB responsive elements linked to a minimal promoter. In some embodiments, the minimal promoter of a gene is a minimal human IL-2 promoter or a CMV promoter. The NFAT responsive elements may comprise, e.g., NFAT1, NFAT2, NFAT3, and/or NFAT4 responsive elements. The NFAT promoter, NF-κB promoter, or a functional variant thereof may comprise any number of binding motifs, e.g., at least two, at least three, at least four, at least five, or at least six, at least seven, at least eight, at least nine, at least ten, at least eleven, or up to twelve binding motifs.


The resulting recombinant expression vector having the DNA molecule thereon is used to transform an appropriate host. This transformation can be performed using methods well known in the art. In some embodiments, a nucleic acid provided herein further comprises nucleotide sequence that encodes a secretory or signal peptide operably linked to the nucleic acid encoding an immunomodulatory polypeptide such that a resultant soluble immunomodulatory polypeptide is recovered from the culture medium, host cell, or host cell periplasm. In other embodiments, the appropriate expression control signals are chosen to allow for membrane expression of an immunomodulatory polypeptide. Furthermore, commercially available kits as well as contract manufacturing companies can also be utilized to make engineered cells or recombinant host cells provided herein.


In some embodiments, the resulting expression vector having the DNA molecule thereon is used to transform, such as transduce, an appropriate cell. The introduction can be performed using methods well known in the art. Exemplary methods include those for transfer of nucleic acids encoding the receptors, including via viral, e.g., retroviral or lentiviral, transduction, transposons, and electroporation. In some embodiments, the expression vector is a viral vector. In some embodiments, the nucleic acid is transferred into cells by lentiviral or retroviral transduction methods.


Any of a large number of publicly available and well-known mammalian host cells, including mammalian T-cells or APCs, can be used in the preparing the polypeptides or engineered cells. The selection of a cell is dependent upon a number of factors recognized by the art. These include, for example, compatibility with the chosen expression vector, toxicity of the peptides encoded by the DNA molecule, rate of transformation, ease of recovery of the peptides, expression characteristics, bio-safety and costs. A balance of these factors must be struck with the understanding that not all cells can be equally effective for the expression of a particular DNA sequence.


In some embodiments, the host cells can be a variety of eukaryotic cells, such as in yeast cells, or with mammalian cells such as Chinese hamster ovary (CHO) or HEK293 cells. In some embodiments, the host cell is a suspension cell and the polypeptide is engineered or produced in cultured suspension, such as in cultured suspension CHO cells, e.g. CHO-S cells. In some examples, the cell line is a CHO cell line that is deficient in DHFR (DHFR−), such as DG44 and DUXB11. In some embodiments, the cell is deficient in glutamine synthase (GS), e.g. CHO-S cells, CHOK1 SV cells, and CHOZN((R)) GS−/− cells. In some embodiments, the CHO cells, such as suspension CHO cells, may be CHO-S-2H2 cells, CHO-S-clone 14 cells, or ExpiCHO-S cells.


In some embodiments, host cells can also be prokaryotic cells, such as with E. coli. The transformed recombinant host is cultured under polypeptide expressing conditions, and then purified to obtain a soluble protein. Recombinant host cells can be cultured under conventional fermentation conditions so that the desired polypeptides are expressed. Such fermentation conditions are well known in the art. Finally, the polypeptides provided herein can be recovered and purified from recombinant cell cultures by any of a number of methods well known in the art, including ammonium sulfate or ethanol precipitation, acid extraction, anion or cation exchange chromatography, phosphocellulose chromatography, hydrophobic interaction chromatography, and affinity chromatography. Protein refolding steps can be used, as desired, in completing configuration of the mature protein. Finally, high performance liquid chromatography (HPLC) can be employed in the final purification steps.


In some embodiments, the cell is an immune cells, such as any described above in connection with preparing engineered cells. In some embodiments, such engineered cells are primary cells. In some embodiments, the engineered cells are autologous to the subject. In some embodiment, the engineered cells are allogeneic to the subject. In some embodiments, the engineered cells are obtained from a subject, such as by leukapheresis, and transformed ex vivo for expression of the immunomodulatory polypeptide, e.g. transmembrane immunomodulatory polypeptide or secretable immunomodulatory polypeptide.


Also provided are nucleic acids encoding any of the variant immunomodulatory polypeptides contained in infectious agents described herein. In some embodiments, the infectious agents deliver the nucleic acids to a cell in the subject, and/or permit expression of the encoded variant polypeptides in the cell. Also provided are nucleic acids that are used to generate, produce or modify such infectious agents. For example, in some embodiments, provided are vectors and/or plasmids that contain nucleic acids encoding the variant immunomodulatory polypeptides, for generation of the infectious agents, delivery to the cells in a subject and/or expression of the variant immunomodulatory polypeptides in the cells in the subject.


In some embodiments, the provided nucleic acids are recombinant viral or bacterial vectors containing nucleic acid sequences encoding the variant immunomodulatory polypeptides. In some embodiments, the recombinant vectors can be used to produce an infectious agent that contains nucleic acid sequences encoding the variant immunomodulatory polypeptides and/or to be delivered to a target cell in the subject for expression by the target cell. In some embodiments, the recombinant vector is an expression vector. In some embodiments, the recombinant vector includes appropriate sequences necessary for generation and/or production of the infectious agent and expression in the target cell.


In some embodiments, the recombinant vector is a plasmid or cosmid. Plasmid or cosmid containing nucleic acid sequences encoding the variant immunomodulatory polypeptides, as described herein, is readily constructed using standard techniques well known in the art. For generation of the infectious agent, the vector or genome can be constructed in a plasmid form that can then be transfected into a packaging or producer cell line or a host bacterium. The recombinant vectors can be generated using any of the recombinant techniques known in the art. In some embodiments, the vectors can include a prokaryotic origin of replication and/or a gene whose expression confers a detectable or selectable marker such as a drug resistance for propagation and/or selection in prokaryotic systems.


In some embodiments, the recombinant vector is a viral vector. Exemplary recombinant viral vectors include a lentiviral vector genome, poxvirus vector genome, vaccinia virus vector genome, adenovirus vector genome, adenovirus-associated virus vector genome, herpes virus vector genome, and alpha virus vector genome. Viral vectors can be live, attenuated, replication conditional or replication deficient, non-pathogenic (defective), replication competent viral vector, and/or is modified to express a heterologous gene product, e.g., the variant immunomodulatory polypeptides provided herein. Vectors for generation of viruses also can be modified to alter attenuation of the virus, which includes any method of increasing or decreasing the transcriptional or translational load.


Exemplary viral vectors that can be used include modified vaccinia virus vectors (see, e.g., Guerra et al., J. Virol. 80:985-98 (2006); Tartaglia et al., AIDS Research and Human Retroviruses 8: 1445-47 (1992); Gheradi et al., J. Gen. Virol. 86:2925-36 (2005); Mayr et al., Infection 3:6-14 (1975); Hu et al., J. Virol. 75: 10300-308 (2001); U.S. Pat. Nos. 5,698,530, 6,998,252, 5,443,964, 7,247,615 and 7,368,116); adenovirus vector or adenovirus-associated virus vectors (see, e.g., Molin et al., J. Virol. 72:8358-61 (1998); Narumi et al., Am J. Respir. Cell Mol. Biol. 19:936-41 (1998); Mercier et al., Proc. Natl. Acad. Sci. USA 101:6188-93 (2004); U.S. Pat. Nos. 6,143,290; 6,596,535; 6,855,317; 6,936,257; 7,125,717; 7,378,087; 7,550,296); retroviral vectors including those based upon murine leukemia virus (MuLV), gibbon ape leukemia virus (GaLV), ecotropic retroviruses, simian immunodeficiency virus (SIV), human immunodeficiency virus (HIV), and combinations (see, e.g., Buchscher et al., J. Virol. 66:2731-39 (1992); Johann et al., J. Virol. 66: 1635-40 (1992); Sommerfelt et al., Virology 176:58-59 (1990); Wilson et al., J. Virol. 63:2374-78 (1989); Miller et al., J. Virol. 65:2220-24 (1991); Miller et al., Mol. Cell Biol. 10:4239 (1990); Kolberg, NIH Res. 4:43 1992; Cornetta et al., Hum. Gene Ther. 2:215 (1991)); lentiviral vectors including those based upon Human Immunodeficiency Virus (HIV-1), HIV-2, feline immunodeficiency virus (FIV), equine infectious anemia virus, Simian Immunodeficiency Virus (SIV), and maedi/visna virus (see, e.g., Pfeifer et al., Annu. Rev. Genomics Hum. Genet. 2: 177-211 (2001); Zufferey et al., J. Virol. 72: 9873, 1998; Miyoshi et al., J. Virol. 72:8150, 1998; Philpott and Thrasher, Human Gene Therapy 18:483, 2007; Engelman et al., J. Virol. 69: 2729, 1995; Nightingale et al., Mol. Therapy, 13: 1121, 2006; Brown et al., J. Virol. 73:9011 (1999); WO 2009/076524; WO 2012/141984; WO 2016/011083; McWilliams et al., J. Virol. 77: 11150, 2003; Powell et al., J. Virol. 70:5288, 1996) or any, variants thereof, and/or vectors that can be used to generate any of the viruses described above. In some embodiments, the recombinant vector can include regulatory sequences, such as promoter or enhancer sequences, that can regulate the expression of the viral genome, such as in the case for RNA viruses, in the packaging cell line (see, e.g., U.S. Pat. Nos. 5,385,839 and 5,168,062).


In some embodiments, the recombinant vector is an expression vector, e.g., an expression vector that permits expression of the encoded gene product when delivered into the target cell, e.g., a cell in the subject, e.g., a tumor cell, an immune cell and/or an APC. In some embodiments, the recombinant expression vectors contained in the infectious agent are capable of expressing the immunomodulatory proteins in the target cell in the subject, under conditions suited to expression of the protein.


In some aspects, nucleic acids or an expression vector comprises a nucleic acid sequence that encodes the immunomodulatory protein operatively linked to appropriate expression control sequences. Methods of affecting this operative linking, either before or after the nucleic acid sequence encoding the immunomodulatory protein is inserted into the vector, are well known. Expression control sequences include promoters, activators, enhancers, operators, ribosomal binding sites, start signals, stop signals, cap signals, polyadenylation signals, and other signals involved with the control of transcription or translation. The promoter can be operably linked to the portion of the nucleic acid sequence encoding the immunomodulatory protein. In some embodiments, the promotor is a constitutively active promotor in the target cell (such as a tissue-specific constitutively active promotor or other constitutive promotor). For example, the recombinant expression vector may also include, lymphoid tissue-specific transcriptional regulatory elements (TRE) such as a B lymphocyte, T lymphocyte, or dendritic cell specific TRE. Lymphoid tissue specific TRE are known in the art (see, e.g., Thompson et al., Mol. Cell. Biol. 12:1043-53 (1992); Todd et al., J. Exp. Med. 177:1663-74 (1993); Penix et al., J. Exp. Med. 178:1483-96 (1993)). In some embodiments, the promotor is an inducible promotor, which may be responsive to an inducing agent (such as a T cell activation signal). In some embodiments, nucleic acids delivered to the target cell in the subject, e.g., tumor cell, immune cell and/or APC, can be operably linked to any of the regulatory elements described above.


In some embodiments, the vector is a bacterial vector, e.g., a bacterial plasmid or cosmid. In some embodiments, the bacterial vector is delivered to the target cell, e.g., tumor cells, immune cells and/or APCs, via bacterial-mediated transfer of plasmid DNA to mammalian cells (also referred to as “bactofection”). In some embodiments, the delivered bacterial vector also contains appropriate expression control sequences for expression in the target cells, such as a promoter sequence and/or enhancer sequences, or any regulatory or control sequences described above. In some embodiments, the bacterial vector contains appropriate expression control sequences for expression and/or secretion of the encoded variant polypeptides in the infectious agent, e.g., the bacterium.


In some embodiments, polypeptides provided herein can also be made by synthetic methods. Solid phase synthesis is the preferred technique of making individual peptides since it is the most cost-effective method of making small peptides. For example, well known solid phase synthesis techniques include the use of protecting groups, linkers, and solid phase supports, as well as specific protection and deprotection reaction conditions, linker cleavage conditions, use of scavengers, and other aspects of solid phase peptide synthesis. Peptides can then be assembled into the polypeptides as provided herein.


IV. METHODS OF ASSESSING ACTIVITY IMMUNE MODULATION OF VARIANT PD-L2 POLYPEPTIDES AND IMMUNOMODULATORY PROTEINS

In some embodiments, the variant PD-L2 polypeptides provided herein (e.g. full-length and/or specific binding fragments or conjugates, stack constructs or fusion thereof, engineered cells or infectious agents) exhibit immunomodulatory activity to modulate T cell activation. In some embodiments, PD-L2 polypeptides modulate IFN-gamma expression in a T cell assay relative to a wild-type or unmodified PD-L2 control. In some cases, modulation of IFN-gamma expression can increase or decrease IFN-gamma expression relative to the control. Assays to determine specific binding and IFN-gamma expression are well-known in the art and include the MLR (mixed lymphocyte reaction) assays measuring interferon-gamma cytokine levels in culture supernatants (Wang et al., Cancer Immunol Res. 2014 September: 2(9):846-56), SEB (staphylococcal enterotoxin B) T cell stimulation assay (Wang et al., Cancer Immunol Res. 2014 September: 2(9):846-56), and anti-CD3 T cell stimulation assays (Li and Kurlander, J Transl Med. 2010: 8: 104).


In some embodiments, a variant PD-L2 polypeptide can in some embodiments increase or, in alternative embodiments, decrease IFN-gamma (interferon-gamma) expression in a primary T-cell assay relative to a wild-type PD-L2 control. In some embodiments, such activity may depend on whether the variant PD-L2 polypeptide is provided in a form for antagonist activity or in a form for agonist activity. In some embodiments, a variant PD-L2 polypeptide or immunomodulatory protein is an antagonist of the inhibitory receptor, such as blocks an inhibitory signal in the cell that may occur to decrease response to activating stimuli, e.g. CD3 and/or CD28 costimulatory signal or a mitogenic signal. Those of skill will recognize that different formats of the primary T-cell assay used to determine an increase or decrease in IFN-gamma expression exist.


In assaying for the ability of a variant PD-L2 to increase or decrease IFN-gamma expression in a primary T-cell assay, a Mixed Lymphocyte Reaction (MLR) assay can be used. In some embodiments, a variant PD-L2 polypeptide or immunomodulatory protein provided in antagonist form, such as soluble form, e.g. variant PD-L2-Fc or secretable immunomodulatory protein, block activity of the PD-1 inhibitory receptor and thereby increase MLR activity in the assay, such as observed by increased production of IFN-gamma in the assay. In some embodiments, a variant PD-L2 polypeptide or immunomodulatory protein provided in agonist form, such as a localizing vIgD stack or conjugate containing a tumor-localizing moiety or an engineered cell expressing a transmembrane immunomodulatory protein as provided, may stimulate activity of the PD-1 inhibitory receptor and thereby decrease MLR activity, such as evidenced by decreased IFN-gamma production. In some embodiments, a variant PD-L2 polypeptide or immunomodulatory protein provided in agonist form, such as a localizing vIgD stack or conjugate containing a tumor-localizing moiety or an engineered cell expressing a transmembrane immunomodulatory protein as provided, may block activity of the PD-1 inhibitory receptor and thereby increase MLR activity, such as increase IFN-gamma production.


Alternatively, in assaying for the ability of a variant PD-L2 to modulate an increase or decrease IFN-gamma expression in a primary T-cell assay, a co-immobilization assay can be used. In a co-immobilization assay, a TCR signal, provided in some embodiments by anti-CD3 antibody, is used in conjunction with a co-immobilized variant PD-L2 to determine the ability to increase or decrease IFN-gamma expression relative to a PD-L2 unmodified or wild-type control. In some embodiments, a variant PD-L2 polypeptide or immunomodulatory protein, e.g. a co-immobilized variant PD-L2-Fc, decreases IFN-gamma production in a co-immobilization assay.


In some embodiments, in assaying for the ability of a variant PD-L2 to modulate an increase or decrease IFN-gamma expression a T cell reporter assay can be used. In some embodiments, the T cell is a Jurkat T cell line or is derived from Jurkat T cell lines. In reporter assays, the reporter cell line (e.g. Jurkat reporter cell) also is generated to overexpress an inhibitory receptor that is the cognate binding partner of the variant IgSF domain polypeptide. For example, in the case of a variant PD-L2, the reporter cell line (e.g. Jurkat reporter cell) is generated to overexpress PD-1. In some embodiments, the reporter T cells also contain a reporter construct containing an inducible promoter responsive to T cell activation operably linked to a reporter. In some embodiments, the reporter is a fluorescent or luminescent reporter. In some embodiments, the reporter is luciferase. In some embodiments, the promoter is responsive to CD3 signaling. In some embodiments, the promoter is an NFAT promoter. In some embodiments, the promoter is responsive to costimulatory signaling, e.g. CD28 costimulatory signaling. In some embodiments, the promoter is an IL-2 promoter.


In aspects of a reporter assay, a reporter cell line is stimulated, such as by co-incubation with antigen presenting cells (APCs) expressing the wild-type ligand of the inhibitory receptor, e.g. PD-L2. In some embodiments, the APCs are artificial APCs. Artificial APCs are well known to a skilled artisan. In some embodiments, artificial APCs are derived from one or more mammalian cell line, such as K562, CHO or 293 cells.


In some embodiments, the Jurkat reporter cells are co-incubated with artificial APCs overexpressing the inhibitory ligand in the presence of the variant IgSF domain molecule or immunomodulatory protein, e.g., variant PD-L2 polypeptide or immunomodulatory protein. In some embodiments, reporter expression is monitored, such as by determining the luminescence or fluorescence of the cells. In some embodiments, normal interactions between its inhibitory receptor and ligand result in a repression of or decrease in the reporter signal, such as compared to control, e.g. reporter expression by co-incubation of control T cells and APCs in which the inhibitory receptor and ligand interaction is not present, e.g. APCs that do not overexpress PD-L2. In some embodiments, a variant PD-L2 polypeptide or immunomodulatory protein provided herein antagonizes the interaction, e.g. when provided in soluble form as a variant PD-L2-Fc or when expressed from the APC as a secretable immunomodulatory protein, thereby resulting in an increase in the reporter signal compared to the absence of the variant PD-L2 polypeptide or immunomodulatory protein. In some cases, certain formats of a variant PD-L2 polypeptide or immunomodulatory protein as provided herein may provide an agonist activity, thereby decreasing reporter expression compared to the absence of the variant PD-L2 polypeptide or immunomodulatory protein.


Use of proper controls is known to those of skill in the art, however, in the aforementioned embodiments, a control typically involves use of the unmodified PD-L2, such as a wild-type of native PD-L2 isoform from the same mammalian species from which the variant PD-L2 was derived or developed. In some embodiments, the wild-type or native PD-L2 is of the same form or corresponding form as the variant. For example, if the variant PD-L2 is a soluble form containing a variant ECD fused to an Fc protein, then the control is a soluble form containing the wild-type or native ECD of PD-L2 fused to the Fc protein. Irrespective of whether the binding affinity and/or selectivity to PD-1 is increased or decreased, a variant PD-L2 in some embodiments will increase IFN-gamma expression and, in alternative embodiments, decrease IFN-gamma expression in a T-cell assay relative to a wild-type PD-L2 control.


In some embodiments, a variant PD-L2 polypeptide or immunomodulatory protein, increases IFN-gamma expression (i.e., protein expression) relative to a wild-type or unmodified PD-L2 control by at least: 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or higher. In other embodiments, a variant PD-L2 or immunomodulatory protein decreases IFN-gamma expression (i.e. protein expression) relative to a wild-type or unmodified PD-L2 control by at least: 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or higher. In some embodiments, the wild-type PD-L2 control is murine PD-L2, such as would typically be used for a variant PD-L2 altered in sequence from that of a wild-type murine PD-L2 sequence. In some embodiments, the wild-type PD-L2 control is human PD-L2, such as would typically be used for a variant PD-L2 altered in sequence from that of a wild-type human PD-L2 sequence.


V. PHARMACEUTICAL FORMULATIONS

Provided herein are compositions containing any of the variant PD-L2 polypeptides, immunomodulatory proteins, conjugates, engineered cells or infectious agents described herein. The pharmaceutical composition can further comprise a pharmaceutically acceptable excipient. For example, the pharmaceutical composition can contain one or more excipients for modifying, maintaining or preserving, for example, the pH, osmolarity, viscosity, clarity, color, isotonicity, odor, sterility, stability, rate of dissolution or release, adsorption, or penetration of the composition. In some aspects, a skilled artisan understands that a pharmaceutical composition containing cells may differ from a pharmaceutical composition containing a protein.


In some embodiments, the pharmaceutical composition is a solid, such as a powder, capsule, or tablet. For example, the components of the pharmaceutical composition can be lyophilized. In some embodiments, the solid pharmaceutical composition is reconstituted or dissolved in a liquid prior to administration.


In some embodiments, the pharmaceutical composition is a liquid, for example variant PD-L2 polypeptides dissolved in an aqueous solution (such as physiological saline or Ringer's solution). In some embodiments, the pH of the pharmaceutical composition is between about 4.0 and about 8.5 (such as between about 4.0 and about 5.0, between about 4.5 and about 5.5, between about 5.0 and about 6.0, between about 5.5 and about 6.5, between about 6.0 and about 7.0, between about 6.5 and about 7.5, between about 7.0 and about 8.0, or between about 7.5 and about 8.5).


In some embodiments, the pharmaceutical composition comprises a pharmaceutically-acceptable excipient, for example a filler, binder, coating, preservative, lubricant, flavoring agent, sweetening agent, coloring agent, a solvent, a buffering agent, a chelating agent, or stabilizer. Examples of pharmaceutically-acceptable fillers include cellulose, dibasic calcium phosphate, calcium carbonate, microcrystalline cellulose, sucrose, lactose, glucose, mannitol, sorbitol, maltol, pregelatinized starch, corn starch, or potato starch. Examples of pharmaceutically-acceptable binders include polyvinylpyrrolidone, starch, lactose, xylitol, sorbitol, maltitol, gelatin, sucrose, polyethylene glycol, methyl cellulose, or cellulose. Examples of pharmaceutically-acceptable coatings include hydroxypropyl methylcellulose (HPMC), shellac, corn protein zein, or gelatin. Examples of pharmaceutically-acceptable disintegrants include polyvinylpyrrolidone, carboxymethyl cellulose, or sodium starch glycolate. Examples of pharmaceutically-acceptable lubricants include polyethylene glycol, magnesium stearate, or stearic acid. Examples of pharmaceutically-acceptable preservatives include methyl parabens, ethyl parabens, propyl paraben, benzoic acid, or sorbic acid. Examples of pharmaceutically-acceptable sweetening agents include sucrose, saccharine, aspartame, or sorbitol. Examples of pharmaceutically-acceptable buffering agents include carbonates, citrates, gluconates, acetates, phosphates, or tartrates.


In some embodiments, the pharmaceutical composition further comprises an agent for the controlled or sustained release of the product, such as injectable microspheres, bio-erodible particles, polymeric compounds (polylactic acid, polyglycolic acid), beads, or liposomes.


In some embodiments, the pharmaceutical composition is sterile. Sterilization may be accomplished by filtration through sterile filtration membranes or radiation. Where the composition is lyophilized, sterilization using this method may be conducted either prior to or following lyophilization and reconstitution. The composition for parenteral administration may be stored in lyophilized form or in solution. In addition, parenteral compositions generally are placed into a container having a sterile access port, for example, an intravenous solution bag or vial having a stopper pierceable by a hypodermic injection needle.


In some embodiments, provided are pharmaceutical compositions containing the transmembrane immunomodulatory proteins, including engineered cells expressing such transmembrane immunomodulatory proteins. In some embodiments, the pharmaceutical compositions and formulations include one or more optional pharmaceutically acceptable carrier or excipient. Such compositions may comprise buffers such as neutral buffered saline, phosphate buffered saline and the like; carbohydrates such as glucose, mannose, sucrose or dextrans, mannitol; proteins; polypeptides or amino acids such as glycine; antioxidants; chelating agents such as EDTA or glutathione; adjuvants (e.g., aluminum hydroxide); and preservatives. Compositions of the present invention are preferably formulated for intravenous administration.


Such a formulation may, for example, be in a form suitable for intravenous infusion. A pharmaceutically acceptable carrier may be a pharmaceutically acceptable material, composition, or vehicle that is involved in carrying or transporting cells of interest from one tissue, organ, or portion of the body to another tissue, organ, or portion of the body. For example, the carrier may be a liquid or solid filler, diluent, excipient, solvent, or encapsulating material, or some combination thereof. Each component of the carrier must be “pharmaceutically acceptable” in that it must be compatible with the other ingredients of the formulation. It also must be suitable for contact with any tissue, organ, or portion of the body that it may encounter, meaning that it must not carry a risk of toxicity, irritation, allergic response, immunogenicity, or any other complication that excessively outweighs its therapeutic benefits.


VI. ARTICLES OF MANUFACTURE AND KITS

Also provided herein are articles of manufacture comprising the pharmaceutical compositions described herein in suitable packaging. Suitable packaging for compositions (such as ophthalmic compositions) described herein are known in the art, and include, for example, vials (such as sealed vials), vessels, ampules, bottles, jars, flexible packaging (e.g., sealed Mylar or plastic bags), and the like. These articles of manufacture may further be sterilized and/or sealed.


Further provided are kits comprising the pharmaceutical compositions (or articles of manufacture) described herein, which may further comprise instruction(s) on methods of using the composition, such as uses described herein. The kits described herein may also include other materials desirable from a commercial and user standpoint, including other buffers, diluents, filters, needles, syringes, and package inserts with instructions for performing any methods described herein.


VII. THERAPEUTIC APPLICATIONS

Provided herein are methods using the provided pharmaceutical compositions containing a variant PD-L2 polypeptide, immunomodulatory protein, conjugate, engineered cell or infectious agent described herein, for modulating an immune response, including in connection with treating a disease or condition in a subject, such as in a human patient. The pharmaceutical compositions described herein (including pharmaceutical composition comprising the variant PD-L2 polypeptides, the immunomodulatory proteins, the conjugates, the engineered cells or the infectious agents described herein) can be used in a variety of therapeutic applications, such as the treatment of a disease. For example, in some embodiments the pharmaceutical composition is used to treat inflammatory or autoimmune disorders, cancer, organ transplantation, viral infections, and/or bacterial infections in a mammal. The pharmaceutical composition can modulate (e.g. increase or decrease) an immune response to treat the disease.


In some embodiments, the provided methods are applicable to therapeutic administration of variant PD-L2 polypeptides, the immunomodulatory proteins, the conjugates, the engineered cells and infectious agents described herein. It is within the level of a skilled artisan, in view of the provided disclosure, to choose a format for the indication depending on the type of modulation of the immune response, e.g. increase or decrease that is desired.


In some embodiments, a pharmaceutical composition provided herein that stimulates the immune response is administered, which can be useful, for example, in the treatment of cancer, viral infections, or bacterial infections. In some embodiments, the pharmaceutical composition contains a variant PD-L2 polypeptide in a format that exhibits antagonist activity of its cognate binding partner PD-1 and/or that inhibits costimulatory signaling via PD-1. Exemplary formats of PD-L2 polypeptide for use in connection with such therapeutic applications include, for example, a variant PD-L2 polypeptide that is soluble (e.g. variant PD-L2-Fc fusion protein), an immunomodulatory protein or “stack” of a variant PD-L2 polypeptide and another IgSF domain, including soluble forms thereof that are Fc fusions, an engineered cell expressing a secretable immunomodulatory protein, or an infectious agent comprising a nucleic acid molecule encoding a secretable immunomodulatory protein, such as for expression and secretion of the secretable immunomodulatory protein in an infected cell (e.g. tumor cell or APC, e.g. dendritic cell). Among such methods are methods carried out by delivery of a variant PD-L2 polypeptide in a soluble format. Exemplary soluble formats are described herein, including formats in which an extracellular portion of a variant PD-L2 polypeptide containing an affinity modified IgSF domain (e.g. IgV) is linked, directly or indirectly, to a multimerization domain, e.g. an Fc domain or region. In some embodiments, such a therapeutic agent is a variant PD-L2-Fc fusion protein.


The provided methods to modulate an immune response can be used to treat a disease or condition, such as a tumor or cancer. In some embodiments, the pharmaceutical composition can be used to inhibit growth of mammalian cancer cells (such as human cancer cells). A method of treating cancer can include administering an effective amount of any of the pharmaceutical compositions described herein to a subject with cancer. The effective amount of the pharmaceutical composition can be administered to inhibit, halt, or reverse progression of cancers, including cancers that are sensitive to modulation of immunological activity, such as by the provided variants or immunomodulatory proteins. Human cancer cells can be treated in vivo, or ex vivo. In ex vivo treatment of a human patient, tissue or fluids containing cancer cells are treated outside the body and then the tissue or fluids are reintroduced back into the patient. In some embodiments, the cancer is treated in a human patient in vivo by administration of the therapeutic composition into the patient. Thus, the present invention provides ex vivo and in vivo methods to inhibit, halt, or reverse progression of the tumor, or otherwise result in a statistically significant increase in progression-free survival (i.e., the length of time during and after treatment in which a patient is living with cancer that does not get worse), or overall survival (also called “survival rate;” i.e., the percentage of people in a study or treatment group who are alive for a certain period of time after they were diagnosed with or treated for cancer) relative to treatment with a control.


The cancers that can be treated by the pharmaceutical compositions and the treatment methods described herein include, but are not limited to, melanoma, bladder cancer, hematological malignancies (leukemia, lymphoma, myeloma), liver cancer, brain cancer, renal cancer, breast cancer, pancreatic cancer (adenocarcinoma), colorectal cancer, lung cancer (small cell lung cancer and non-small-cell lung cancer), spleen cancer, cancer of the thymus or blood cells (i.e., leukemia), prostate cancer, testicular cancer, ovarian cancer, uterine cancer, gastric carcinoma, a musculoskeletal cancer, a head and neck cancer, a gastrointestinal cancer, a germ cell cancer, or an endocrine and neuroendocrine cancer. In some embodiments, the cancer is Ewing's sarcoma. In some embodiments, the cancer is a lymphoma, lymphoid leukemia, myeloid leukemia, cervical cancer, neuroblastoma, or multiple myeloma.


In some embodiments, the pharmaceutical composition is administered as a monotherapy (i.e., as a single agent) or as a combination therapy (i.e., in combination with one or more additional anticancer agents, such as a chemotherapeutic drug, a cancer vaccine, or an immune checkpoint inhibitor. In some embodiments, the pharmaceutical composition can also be administered with radiation therapy. In some aspects of the present disclosure, the immune checkpoint inhibitor is nivolumab, tremelimumab, pembrolizumab, ipilimumab, or the like.


In some embodiments, the pharmaceutical composition suppresses an immune response, which can be useful in the treatment of inflammatory or autoimmune disorders, or organ transplantation. In some embodiments, the pharmaceutical composition contains a variant PD-L2 polypeptide in a format that exhibits agonist activity of its cognate binding partner PD-1 and/or that stimulates inhibitory signaling via PD-1. Exemplary formats of a PD-L2 polypeptide for use in connection with such therapeutic applications include, for example, an immunomodulatory protein or “stack” of a variant PD-L2 polypeptide and an IgSF domain or variant thereof that localizes to a cell or tissue of an inflammatory environment, a conjugate containing a variant PD-L2 polypeptide linked to a moiety that localizes to a cell or tissue of an inflammatory environment, an engineered cell expressing a transmembrane immunomodulatory protein, or an infectious agent comprising a nucleic acid molecule encoding a transmembrane immunomodulatory protein, such as for expression of the transmembrane immunomodulatory protein in an infected cell.


The provided methods to modulate an immune response can be used to treat a disease or condition, such as an inflammatory or autoimmune disorder. In some embodiments, the inflammatory or autoimmune disorder is Antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis, a vasculitis, an autoimmune skin disease, transplantation, a Rheumatic disease, an inflammatory gastrointestinal disease, an inflammatory eye disease, an inflammatory neurological disease, an inflammatory pulmonary disease, an inflammatory endocrine disease, or an autoimmune hematological disease.


In some embodiments, the inflammatory and autoimmune disorders that can be treated by the pharmaceutical composition described herein is Addison's Disease, allergies, alopecia areata, Alzheimer's, antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis, ankylosing spondylitis, antiphospholipid syndrome (Hughes Syndrome), asthma, atherosclerosis, rheumatoid arthritis, autoimmune hemolytic anemia, autoimmune hepatitis, autoimmune inner ear disease, autoimmune lymphoproliferative syndrome, autoimmune myocarditis, autoimmune oophoritis, autoimmune orchitis, azoospermia, Behcet's Disease, Berger's Disease, bullous pemphigoid, cardiomyopathy, cardiovascular disease, celiac Sprue/coeliac disease, chronic fatigue immune dysfunction syndrome (CFIDS), chronic idiopathic polyneuritis, chronic inflammatory demyelinating, polyradicalneuropathy (CIDP), chronic relapsing polyneuropathy (Guillain-Barré syndrome), Churg-Strauss Syndrome (CSS), cicatricial pemphigoid, cold agglutinin disease (CAD), COPD (chronic obstructive pulmonary disease), CREST syndrome, Crohn's disease, dermatitis, herpetiformus, dermatomyositis, diabetes, discoid lupus, eczema, epidermolysis bullosa acquisita, essential mixed cryoglobulinemia, Evan's Syndrome, exopthalmos, fibromyalgia, Goodpasture's Syndrome, Graves' Disease, Hashimoto's thyroiditis, idiopathic pulmonary fibrosis, idiopathic thrombocytopenia purpura (ITP), IgA nephropathy, immunoproliferative disease or disorder, inflammatory bowel disease (IBD), interstitial lung disease, juvenile arthritis, juvenile idiopathic arthritis (JIA), Kawasaki's Disease, Lambert-Eaton Myasthenic Syndrome, lichen planus, lupus nephritis, lymphocytic hypophysitis, Meniere's Disease, Miller Fish Syndrome/acute disseminated encephalomyeloradiculopathy, mixed connective tissue disease, multiple sclerosis (MS), muscular rheumatism, myalgic encephalomyelitis (ME), myasthenia gravis, ocular inflammation, pemphigus foliaceus, pemphigus vulgaris, pernicious anaemia, polyarteritis nodosa, polychondritis, polyglandular syndromes (Whitaker's syndrome), polymyalgia rheumatica, polymyositis, primary agammaglobulinemia, primary biliary cirrhosis/autoimmune cholangiopathy, psoriasis, psoriatic arthritis, Raynaud's Phenomenon, Reiter's Syndrome/reactive arthritis, restenosis, rheumatic fever, rheumatic disease, sarcoidosis, Schmidt's syndrome, scleroderma, Sjörgen's Syndrome, stiff-man syndrome, systemic lupus erythematosus (SLE), systemic scleroderma, Takayasu arteritis, temporal arteritis/giant cell arteritis, thyroiditis, Type 1 diabetes, ulcerative colitis, uveitis, vasculitis, vitiligo, interstitial bowel disease or Wegener's Granulomatosis. In some embodiments, the inflammatory or autoimmune disorder is selected from interstitial bowel disease, transplant, Crohn's disease, ulcerative colitis, multiple sclerosis, asthma, rheumatoid arthritis, and psoriasis.


In some embodiments, the pharmaceutical composition is administered to modulate an autoimmune condition. For example, suppressing an immune response can be beneficial in methods for inhibiting rejection of a tissue, cell, or organ transplant from a donor by a recipient. Accordingly, in some embodiments, the pharmaceutical compositions described herein are used to limit or prevent graft-related or transplant related diseases or disorders, such as graft versus host disease (GVHD). In some embodiments, the pharmaceutical compositions are used to suppress autoimmune rejection of transplanted or grafted bone marrow, organs, skin, muscle, neurons, islets, or parenchymal cells.


Pharmaceutical compositions comprising engineered cells and the methods described herein can be used in adoptive cell transfer applications. In some embodiments, cell compositions comprising engineered cells can be used in associated methods to, for example, modulate immunological activity in an immunotherapy approach to the treatment of, for example, a mammalian cancer or, in other embodiments the treatment of autoimmune disorders. The methods employed generally comprise a method of contacting a TIP of the present invention with a mammalian cell under conditions that are permissive to specific binding of the affinity modified IgSF domain and modulation of the immunological activity of the mammalian cell. In some embodiments, immune cells (such as tumor infiltrating lymphocytes (TILs), T-cells (including CD8+ or CD4+ T-cells), or APCs) are engineered to express as a membrane protein and/or as a soluble variant PD-L2 polypeptide, immunomodulatory protein, or conjugate as described herein. The engineered cells can then be contact a mammalian cell, such as an APC, a second lymphocyte or tumor cell in which modulation of immunological activity is desired and under conditions that are permissive of specific binding of the affinity modified IgSF domain to a counter-structure on the mammalian cell such that immunological activity can be modulated in the mammalian cell. Cells can be contacted in vivo or ex vivo.


In some embodiments, the engineered cells are autologous cells. In other embodiments, the cells are allogeneic. In some embodiments, the cells are autologous engineered cells reinfused into the mammal from which it was isolated. In some embodiments, the cells are allogenic engineered cells infused into the mammal. In some embodiments, the cells are harvested from a patient's blood or tumor, engineered to express a polypeptide (such as the variant PD-L2 polypeptide, immunomodulatory protein, or conjugate as described herein), expanded in an in vitro culture system (for example, by stimulating the cells), and reinfused into the patient to mediate tumor destruction. In some embodiments, the methods are conducted by adoptive cell transfer wherein cells expressing the TIP (e.g., a T-cell) are infused back into the patient. In some embodiments, the therapeutic compositions and methods of the invention are used in the treatment of a mammalian patient of cancers such as lymphoma, lymphoid leukemia, myeloid leukemia, cervical cancer, neuroblastoma, or multiple myeloma.


In some embodiments, the pharmaceutical composition is administered to a subject. Generally, dosages and routes of administration of the pharmaceutical composition are determined according to the size and condition of the subject, according to standard pharmaceutical practice. For example, the therapeutically effective dose can be estimated initially either in cell culture assays or in animal models such as mice, rats, rabbits, dogs, pigs, or monkeys. An animal model may also be used to determine the appropriate concentration range and route of administration. Such information can then be used to determine useful doses and routes for administration in humans. The exact dosage will be determined in light of factors related to the subject requiring treatment. Dosage and administration are adjusted to provide sufficient levels of the active compound or to maintain the desired effect. Factors that may be taken into account include the severity of the disease state, the general health of the subject, the age, weight, and gender of the subject, time and frequency of administration, drug combination(s), reaction sensitivities, and response to therapy.


Long-acting pharmaceutical compositions may be administered every 3 to 4 days, every week, or biweekly depending on the half-life and clearance rate of the particular formulation. The frequency of dosing will depend upon the pharmacokinetic parameters of the molecule in the formulation used. Typically, a composition is administered until a dosage is reached that achieves the desired effect. The composition may therefore be administered as a single dose, or as multiple doses (at the same or different concentrations/dosages) over time, or as a continuous infusion. Further refinement of the appropriate dosage is routinely made. Appropriate dosages may be ascertained through use of appropriate dose-response data. A number of biomarkers or physiological markers for therapeutic effect can be monitored including T cell activation or proliferation, cytokine synthesis or production (e.g., production of TNF-α, IFN-γ, IL-2), induction of various activation markers (e.g., CD25, IL-2 receptor), inflammation, joint swelling or tenderness, serum level of C-reactive protein, anti-collagen antibody production, and/or T cell-dependent antibody response(s).


In some embodiments, the pharmaceutical composition is administered to a subject through any route, including orally, transdermally, by inhalation, intravenously, intra-arterially, intramuscularly, direct application to a wound site, application to a surgical site, intraperitoneally, by suppository, subcutaneously, intradermally, transcutaneously, by nebulization, intrapleurally, intraventricularly, intra-articularly, intraocularly, or intraspinally.


In some embodiments, the dosage of the pharmaceutical composition is a single dose or a repeated dose. In some embodiments, the doses are given to a subject once per day, twice per day, three times per day, or four or more times per day. In some embodiments, about 1 or more (such as about 2 or more, about 3 or more, about 4 or more, about 5 or more, about 6 or more, or about 7 or more) doses are given in a week. In some embodiments, multiple doses are given over the course of days, weeks, months, or years. In some embodiments, a course of treatment is about 1 or more doses (such as about 2 or more does, about 3 or more doses, about 4 or more doses, about 5 or more doses, about 7 or more doses, about 10 or more doses, about 15 or more doses, about 25 or more doses, about 40 or more doses, about 50 or more doses, or about 100 or more doses).


In some embodiments, an administered dose of the pharmaceutical composition is about 1 μg of protein per kg subject body mass or more (such as about 2 μg of protein per kg subject body mass or more, about 5 μg of protein per kg subject body mass or more, about 10 of protein per kg subject body mass or more, about 25 μg of protein per kg subject body mass or more, about 50 μg of protein per kg subject body mass or more, about 100 μg of protein per kg subject body mass or more, about 250 μg of protein per kg subject body mass or more, about 500 of protein per kg subject body mass or more, about 1 mg of protein per kg subject body mass or more, about 2 mg of protein per kg subject body mass or more, or about 5 mg of protein per kg subject body mass or more).


In some embodiments, a therapeutic amount of a cell composition is administered. Typically, precise amount of the compositions of the present invention to be administered can be determined by a physician with consideration of individual differences in age, weight, tumor size, extent of infection or metastasis, and condition of the patient (subject). It can generally be stated that a pharmaceutical composition comprising engineered cells, e.g. T cells, as described herein may be administered at a dosage of 104 to 109 cells/kg body weight, such as 105 to 106 cells/kg body weight, including all integer values within those ranges. Engineered cell compositions, such as T cell compositions, may also be administered multiple times at these dosages. The cells can be administered by using infusion techniques that are commonly known in immunotherapy (see, e.g., Rosenberg et al, New Eng. J. of Med. 319: 1676, 1988). The optimal dosage and treatment regime for a particular patient can readily be determined by one skilled in the art of medicine by monitoring the patient for signs of disease and adjusting the treatment accordingly.


In some embodiments, the pharmaceutical composition contains infectious agents containing nucleic acid sequences encoding the immunomodulatory variant polypeptides. In some embodiments, the pharmaceutical composition contains a dose of infectious agents suitable for administration to a subject that is suitable for treatment. In some embodiments, the pharmaceutical composition contains an infectious agent that is a virus, at a single or multiple dosage amount, of between about between or between about 1×105 and about 1×1012 plaque-forming units (pfu), 1×106 and 1×1010 pfu, or 1×107 and 1×1010 pfu, each inclusive, such as at least or at least about or at about 1×106, 1×107, 1×108, 1×109, 2×109, 3×109, 4×109, 5×109 pfu or about 1×1010 pfu. In some embodiments, the pharmaceutical composition can contain a virus concentration of from or from about 105 to about 1010 pfu/mL, for example, 5×106 to 5×109 or 1×107 to 1×109 pfu/mL, such as at least or at least about or at about 106 pfu/mL, 107 pfu/mL, 108 pfu/mL or 109 pfu/mL. In some embodiments, the pharmaceutical composition contains an infectious agent that is a bacterium, at a single or multiple dosage amount, of between about between or between about 1×103 and about 1×109 colony-forming units (cfu), 1×104 and 1×109 cfu, or 1×105 and 1×107 cfu, each inclusive, such as at least or at least about or at about 1×104, 1×105, 1×106, 1×107, 1×108 or 1×109 cfu. In some embodiments, the pharmaceutical composition can contain a bacterial concentration of from or from about 103 to about 108 cfu/mL, for example, 5×105 to 5×107 or 1×106 to 1×107 cfu/mL, such as at least or at least about or at about 105 cfu/mL, 106 cfu/mL, 107 cfu/mL or 108 cfu/mL.


A variety of means are known for determining if administration of a therapeutic composition of the invention sufficiently modulates immunological activity by eliminating, sequestering, or inactivating immune cells mediating or capable of mediating an undesired immune response; inducing, generating, or turning on immune cells that mediate or are capable of mediating a protective immune response; changing the physical or functional properties of immune cells; or a combination of these effects. Examples of measurements of the modulation of immunological activity include, but are not limited to, examination of the presence or absence of immune cell populations (using flow cytometry, immunohistochemistry, histology, electron microscopy, polymerase chain reaction (PCR)); measurement of the functional capacity of immune cells including ability or resistance to proliferate or divide in response to a signal (such as using T-cell proliferation assays and pepscan analysis based on 3H-thymidine incorporation following stimulation with anti-CD3 antibody, anti-T-cell receptor antibody, anti-CD28 antibody, calcium ionophores, PMA (phorbol 12-myristate 13-acetate) antigen presenting cells loaded with a peptide or protein antigen; B cell proliferation assays); measurement of the ability to kill or lyse other cells (such as cytotoxic T cell assays); measurements of the cytokines, chemokines, cell surface molecules, antibodies and other products of the cells (e.g., by flow cytometry, enzyme-linked immunosorbent assays, Western blot analysis, protein microarray analysis, immunoprecipitation analysis); measurement of biochemical markers of activation of immune cells or signaling pathways within immune cells (e.g., Western blot and immunoprecipitation analysis of tyrosine, serine or threonine phosphorylation, polypeptide cleavage, and formation or dissociation of protein complexes; protein array analysis; DNA transcriptional, profiling using DNA arrays or subtractive hybridization); measurements of cell death by apoptosis, necrosis, or other mechanisms (e.g., annexin V staining, TUNEL assays, gel electrophoresis to measure DNA laddering, histology; fluorogenic caspase assays, Western blot analysis of caspase substrates); measurement of the genes, proteins, and other molecules produced by immune cells (e.g., Northern blot analysis, polymerase chain reaction, DNA microarrays, protein microarrays, 2-dimensional gel electrophoresis, Western blot analysis, enzyme linked immunosorbent assays, flow cytometry); and measurement of clinical symptoms or outcomes such as improvement of autoimmune, neurodegenerative, and other diseases involving self-proteins or self-polypeptides (clinical scores, requirements for use of additional therapies, functional status, imaging studies) for example, by measuring relapse rate or disease severity (using clinical scores known to the ordinarily skilled artisan) in the case of multiple sclerosis, measuring blood glucose in the case of type I diabetes, or joint inflammation in the case of rheumatoid arthritis.


VIII. EXEMPLARY EMBODIMENTS

Among the provided embodiments are:


1. A variant PD-L2 polypeptide, comprising an IgV domain or a specific binding fragment thereof, an IgC domain or a specific binding fragment thereof, or both, wherein the variant PD-L2 polypeptide comprises one or more amino acid modifications at one or more positions in an unmodified PD-L2 or a specific binding fragment thereof corresponding to position(s) selected from 2, 12, 13, 15, 18, 23, 24, 28, 31, 32, 33, 36, 37, 39, 44, 45, 46, 47, 48, 58, 59, 65, 67, 69, 71, 72, 73, 74, 75, 76, 77, 82, 85, 86, 89, or 91 with reference to numbering of SEQ ID NO:31.


2. The variant PD-L2 polypeptide of embodiment 1, wherein the amino acid modification is an amino acid substitution, insertion or deletion.


3. The variant PD-L2 polypeptide of embodiment 1 or embodiment 2, wherein the unmodified PD-L2 is a mammalian PD-L2 or a specific binding fragment thereof.


4. The variant PD-L2 polypeptide of any of embodiments 1-3, wherein the unmodified PD-L2 is a human PD-L2 or a specific binding fragment thereof.


5. The variant PD-L2 polypeptide of any one of embodiments 1-4, wherein the unmodified PD-L2 comprises (i) the sequence of amino acids set forth in SEQ ID NO:31, (ii) a sequence of amino acids that has at least 95% sequence identity to SEQ ID NO:31; or (iii) a portion thereof comprising an IgV domain or IgC domain or specific binding fragments thereof or both.


6. The variant PD-L2 polypeptide of any one of embodiments 1-5, wherein:


the specific binding fragment of the IgV domain or IgC domain has a length of at least 50, 60, 70, 80, 90, 100, 110 or more amino acids; or


the specific binding fragment of the IgV domain comprises a length that is at least 80% of the length of the IgV domain set forth as amino acids 24-130 of SEQ ID NO:4 and/or the specific binding fragment of the IgC domain comprises a length that is at least 80% of the length of the IgC domain set forth as amino acids 122-203 of SEQ ID NO:4.


7. The variant PD-L2 polypeptide of any one of embodiments 1-6, wherein:


the variant PD-L2 comprises up to 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 amino acid modifications, optionally amino acid substitutions, insertions and/or deletions; or


the variant PD-L2 polypeptide comprises a sequence of amino acids that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% sequence identity to SEQ ID NO:31 or a specific binding fragment thereof.


8. The variant PD-L2 polypeptide of any of embodiments 1-7, wherein the variant PD-L2 polypeptide exhibits altered binding to the ectodomain of PD-1 or RGMb compared to the unmodified PD-L2.


9. The variant PD-L2 polypeptide of any of embodiments 1-8, wherein the variant PD-L2 polypeptide exhibits altered binding to the ectodomain of PD-1 compared to the unmodified PD-L2.


10. The variant PD-L2 polypeptide of embodiment 8 or embodiment 9, wherein the altered binding is altered binding affinity and/or altered binding selectivity.


11. The variant PD-L2 polypeptide of any of embodiments 1-10, wherein the one or more amino acid modifications are selected from F2L, 112V, I13V, H15Q, N18D, N24S, C23S, G28V, N24D, V31A, V31M, N32D, L33P, L33H, L33F, I36V, T37A, S48C, S39I, E44D, N45S, D46E, T47A, E58G, E59G, K65R, S67L, H69L, P71S, Q72H, V73A, Q74R, R76G, D77N, Q82R, I85F, I86T, V89D, W91R, or a conservative amino acid substitution thereof.


12. The variant PD-L2 polypeptide of any of embodiments 1-11, wherein the one or more amino acid modifications are selected from among H15Q, N24D, E44D, V89D, Q82R/V89D,


E59G/Q82R, S39I/V89D, S67L/V89D, S67L/I85F, S67L/I86T, H15Q/K65R, H15Q/Q72H/V89D, H15Q/S67L/R76G, H15Q/R76G/I85F, H15Q/T47A/Q82R, H15Q/Q82R/V89D, H15Q/C23S/I86T, H15Q/S39I/I86T, E44D/V89D/W91R, I13V/S67L/V89D, H15Q/S67L/I86T, I13V/H15Q/S67L/I86T, I13V/H15Q/E44D/V89D, I13V/S39I/E44D/Q82R/V89D, I13V/E44D/Q82R/V89D, I13V/Q72H/R76G/I86T, I13V/H15Q/R76G/I85F, H15Q/S39I/R76G/V89D, H15Q/S67L/R76G/I85F, H15Q/T47A/Q72H/R76G/I86T, H15Q/T47A/Q72H/R76G, I13V/H15Q/T47A/Q72H/R76G, H15Q/E44D/R76G/I85F, H15Q/S39I/S67L/V89D, H15Q/N32D/S67L/V89D, N32D/S67L/V89D, H15Q/S67L/Q72H/R76G/V89D, H15Q/Q72H/Q74R/R76G/I86T, G28V/Q72H/R76G/I86T, I13V/H15Q/S39I/E44D/S67L, E44D/S67L/Q72H/Q82R/V89D, H15Q/V89D, H15Q/T47A, I13V/H15Q/Q82R, I13V/H15Q/V89D, I13V/S67L/Q82R/V89D, I13V/H15Q/Q82R/V89D, H15Q/V31M/S67L/Q82R/V89D, I13V/H15Q/T47A/Q82R, I13V/H15Q/V31A/N45S/Q82R/V89D, H15Q/T47A/H69L/Q82R/V89D, I13V/H15Q/T47A/H69L/R76G/V89D, I12V/I13V/H15Q/T47A/Q82R/V89D, I13V/H15Q/R76G/D77N/Q82R/V89D, I13V/H15Q/T47A/R76G/V89D, I13V/H15Q/T47A/Q82R/V89D, I13V/H15Q/N24D/Q82R/V89D, I13V/H15Q/I36V/T47A/S67L/V89D, H15Q/T47A/K65R/S67L/Q82R/V89D, H15Q/L33P/T47A/S67L/P71S/V89D, I13V/H15Q/Q72H/R76G/I86T, H15Q/T47A/S67L/Q82R/V89D, F2L/H15Q/D46E/T47A/Q72H/R76G/Q82R/V89D, I13V/H15Q/L33F/T47A/Q82R/V89D, I13V/H15Q/T47A/E58G/S67L/Q82R/V89D, H15Q/N24S/T47A/Q72H/R76G/V89D, I13V/H15Q/E44V/T47A/Q82R/V89D, H15Q/N18D/T47A/Q72H/V73A/R76G/I86T/V89D, I13V/H15Q/T37A/E44D/S48C/S67L/Q82R/V89D, H15Q/L33H/S67L/R76G/Q82R/V89D, I13V/H15Q/T47A/Q72H/R76G/I86T, H15Q/S39I/E44D/Q72H/V75G/R76G/Q82R/V89D, H15Q/T47A/S67L/R76G/Q82R/V89D, or I13V/H15Q/T47A/S67L/Q72H/R76G/Q82R/V89D.


13. The variant PD-L2 polypeptide of any of embodiments 1-12, wherein the one or more amino acid substitutions correspond to position(s) selected from 13, 15, 39, 44, 47 67, 72, 76, 82, 85, 86, or 89, optionally wherein the one or more amino acid substitutions are selected from I13V, H15Q, E44D, T47A, S67L, Q72H, R76G, Q82R, I85F, I86T, V89D, or a conservative amino acid substitution thereof.


14. The variant PD-L2 polypeptide of any of embodiments 1-13, wherein the one or more amino acid substitutions correspond to position(s) selected from 13, 15, 44, 47, 67, 72, 76, 82, 86, or 89, optionally wherein the one or more amino acid substitutions are selected from I13V, H15Q, E44D, T47A, S67L, Q72H, R76G, Q82R, I86T, V89D, or a conservative amino acid substitution thereof.


15. The variant PD-L2 polypeptide of any of embodiments 1-14, wherein the variant PD-L2 polypeptide comprises amino acid modifications I13V/H15Q, I13V/T47A, I13V/S67L, I13V/Q72H, I13V/Q72H, I13V/R76G, I13V/Q82R, I13V/I86T, I13V/V89D, H15Q/T47A, H15Q/S67L, H15Q/Q72H, H15Q/Q72H, H15Q/R76G, H15Q/Q82R, H15Q/I86T, H15Q/V89D, T47A/S67L, T47A/Q72H, T47A/Q72H, T47A/R76G, T47A/Q82R, T47A/I86T, T47A/V89D, S67L/Q72H, S67L/Q72H, S67L/R76G, S67L/Q82R, S67L/I86T, S67L/V89D, Q72H/R76G, Q72H/Q82R, Q72H/I86T, Q72H/V89D, R76G/Q82R, R76G/I86T, R76G/V89D, Q82R/I86T, Q82R/V89D or I86T/V89D.


16. The variant PD-L2 polypeptide of any of embodiments 1-11, wherein the variant PD-L2 polypeptide comprises amino acid modifications H15Q/S62L/Q82R, H15Q/S62L/V89D, H15Q/Q82R/V89D, or S62L/Q82R/V89D.


17. The variant PD-L2 polypeptide of any of embodiments 1-16, wherein the variant PD-L2 polypeptide comprises amino acid modifications H15Q/T47A/K65R/S67L/Q82R/V89D.


18. The variant PD-L2 polypeptide of any of embodiments 1-17, wherein the variant PD-L2 polypeptide comprises or consists of the IgV domain or a specific fragment thereof and the IgC domain or a specific fragment thereof.


19. The variant PD-L2 polypeptide of any of embodiments 1-18, comprising or consisting of the sequence of amino acids set forth in any of SEQ ID NOS: 56-106, 108-114, 116-132 or a specific binding fragment thereof, or a sequence of amino acids that exhibits at least 95% sequence identity to any of SEQ ID NOS: 56-106, 108-114, 116-132 or a specific binding fragment thereof and that contains the one or more of the amino acid substitutions thereof.


20. The variant PD-L2 polypeptide of any of embodiments 1-17, wherein the variant PD-L2 polypeptide comprises or consists of the IgV domain or a specific binding fragment thereof.


21. The variant PD-L2 polypeptide of any of embodiments 1-17 and 20, wherein the IgV domain or specific binding fragment thereof is the only PD-L2 portion of the variant PD-L2 polypeptide.


22. The variant PD-L2 polypeptide of any of embodiments 1-21, comprising or consisting of the sequence of amino acids set forth in any of SEQ ID NOS: 133-183, 185-191, 193-209, 268-318, 320-343 or a specific binding fragment thereof, or a sequence of amino acids that exhibits at least 95% sequence identity to any of SEQ ID NOS: 133-183, 185-191, 193-209, 268-318, 320-343 or a specific binding fragment thereof and that comprises the one or more of the amino acid modifications thereof.


23. The variant PD-L2 polypeptide of any of embodiments 1-17, wherein the IgC domain or specific binding fragment thereof is the only PD-L2 portion of the variant PD-L2 polypeptide.


24. The variant PD-L2 polypeptide of any of embodiments 1-23, wherein the variant PD-L2 polypeptide specifically binds to the ectodomain of PD-1 or RGMb with increased affinity compared to the binding of the unmodified PD-L2 to the ectodomain of PD-1 or RGMb.


25. The variant PD-L2 polypeptide of any of embodiments 1-24, wherein the variant PD-L2 polypeptide specifically binds to the ectodomain of PD-1 with increased affinity compared to the binding of the unmodified PD-L2 to the ectodomain of PD-1.


26. The variant PD-L2 polypeptide of any of embodiments 1-25, wherein the variant PD-L2 polypeptide specifically binds to the ectodomain of PD-1 and the ectodomain of RGMb each with increased affinity compared to the binding of the unmodified PD-L2 to the ectodomain of PD-1 and the ectodomain of RGMb.


27. The variant PD-L2 polypeptide of any of embodiments 1-26, wherein the variant PD-L2 polypeptide specifically binds to the ectodomain of PD-1 with increased affinity and specifically binds to the ectodomain of the other of RGMb with decreased affinity compared to the binding of the unmodified PD-L2 to the ectodomain of the other of RGMb.


28. The variant PD-L2 polypeptide of any of embodiments 24-27, wherein the increased affinity to the ectodomain of PD-1 is increased more than 1.2-fold, 1.5-fold, 2-fold, 3-fold, 4-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold, 20-fold, 30-fold, 40-fold, 50-fold or 60-fold compared to the unmodified PD-L2.


29. The variant PD-L2 polypeptide of embodiment 24 or embodiment 26, wherein the increased affinity to the ectodomain of RGMb is increased more than 1.2-fold, 1.5-fold, 2-fold, 3-fold, 4-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold, 20-fold, 30-fold, 40-fold, 50-fold or 60-fold compared to the unmodified PD-L2.


30. The variant PD-L2 polypeptide of embodiment 27, wherein the decreased affinity to the ectodomain of RGMb is decreased more than 1.2-fold, 1.5-fold, 2-fold, 3-fold, 4-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold, 20-fold, 30-fold, 40-fold, 50-fold or 60-fold compared to the unmodified PD-L2.


31. The variant PD-L2 polypeptide of any of embodiments 1-30, wherein the variant polypeptide specifically binds to the ectodomain of PD-1 with increased selectivity compared to the unmodified PD-L2.


32. The variant PD-L2 polypeptide of embodiment 31, wherein the increased selectivity comprises a greater ratio of binding of the variant polypeptide for PD-1 versus RGMb compared to the ratio of binding of the unmodified PD-L2 polypeptide for PD-1 versus RGMb.


33. The variant PD-L2 polypeptide of embodiment 32, wherein the ratio is greater by at least or at least about 1.5-fold, 2.0-fold, 3.0-fold, 4.0-fold, 5.0-fold, 10-fold, 15-fold, 20-fold, 30-fold, 40-fold, 50-fold or more.


34. The variant PD-L2 polypeptide of any of embodiments 9-33, wherein the PD-1 is a human PD-1.


35. The variant PD-L2 polypeptide of any of embodiments 9-34, wherein the RGMb is a human RGMb.


36. The variant PD-L2 polypeptide of any of embodiments 1-35, wherein the binding activity is altered (increased or decreased) more than 1.2-fold, 1.5-fold, 2-fold, 3-fold, 4-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold, 20-fold, 30-fold 40-fold or 50-fold compared to the unmodified PD-L2.


37. The variant PD-L2 polypeptide of any of embodiments 1-34 that is a soluble protein.


38. The variant PD-L2 polypeptide of any of embodiments 1-37, wherein:


the variant PD-L2 polypeptide lacks the PD-L2 transmembrane domain and intracellular signaling domain; and/or


the variant PD-L2 polypeptide is not capable of being expressed on the surface of a cell.


39. The variant PD-L2 polypeptide of any of embodiments 1-38, wherein the variant PD-L2 polypeptide is linked to a moiety that increases biological half-life of the polypeptide.


40. The variant PD-L2 polypeptide of any of embodiments 1-39, wherein the variant PD-L2 polypeptide is linked to a multimerization domain. 41. The variant PD-L2 polypeptide of embodiment 40, wherein the variant PD-L2 polypeptide is linked to an Fc domain or a variant Fc domain with reduced effector function.


42. The variant PD-L2 polypeptide of any of embodiments 39-41, wherein:


the Fc domain is mammalian, optionally human; or


the variant Fc domain comprises one or more amino acid modifications compared to an unmodified Fc domain that is mammalian, optionally human.


43. The variant PD-L2 polypeptide of any one of embodiments 41 and embodiment 42, wherein the Fc domain or variant thereof comprises the sequence of amino acids set forth in SEQ ID NO:211 or SEQ ID NO:212 or a sequence of amino acids that exhibits at least 85% sequence identity to SEQ ID NO:211 or SEQ ID NO:212.


44. The variant PD-L2 polypeptide of any of embodiments 41-43, wherein the Fc domain comprises one or more amino acid modifications selected from among E233P, L234A, L234V, L235A, L235E, G236del, G237A, S267K, N297G, V302C, and K447del each by EU numbering.


45. The variant PD-L2 polypeptide of any of embodiments 40-44, wherein the Fc domain comprises the amino acid modification C220S by EU numbering.


46. The variant PD-L2 polypeptide of any of embodiments 40-45, wherein the Fc domain comprises the sequence of amino acids set forth in any of SEQ ID NOS: 1189, 1205, 1206, 1207, 1739, 1738, 1739, 1740 or a sequence of amino acids that exhibits at least 85% sequence identity to any of SEQ ID NOS: 1189, 1205, 1206, 1207, 1739, 1738, 1739, 1740 and exhibits reduced effector function.


47. The variant PD-L2 polypeptide of any of embodiments 41-46, wherein the variant PD-L2 polypeptide is linked indirectly via a linker, optionally a G45 linker.


48. The variant PD-L2 polypeptide of any of embodiments 1-47, wherein the variant PD-L2 polypeptide is a transmembrane immunomodulatory protein further comprising a transmembrane domain, optionally wherein the transmembrane domain is linked, directly or indirectly, to the extracellular domain (ECD) or specific binding fragment thereof of the variant PD-L2 polypeptide.


49. The variant PD-L2 polypeptide of embodiment 48, wherein the transmembrane domain comprises the sequence of amino acids set forth as residues 221-241 of SEQ ID NO:4 or a functional variant thereof that exhibits at least 85% sequence identity to residues 221-241 of SEQ ID NO:4.


50. The variant PD-L2 polypeptide of embodiment 48 or embodiment 49, further comprising a cytoplasmic signaling domain, optionally wherein the cytoplasmic domain is linked, directly or indirectly, to the transmembrane domain.


51. The variant PD-L2 polypeptide of embodiment 50, wherein the cytoplasmic signaling domain comprises the sequence of amino acids set forth as residues 242-273 of SEQ ID NO:4 or a functional variant thereof that exhibits at least 85% sequence identity to residues 242-273 of SEQ ID NO:4.


52. The variant PD-L2 polypeptide of any of embodiments 1-51, wherein the variant PD-L2 increases IFN-gamma (interferon-gamma) expression relative to the unmodified PD-L2 in an in vitro T-cell assay.


53. The variant PD-L2 polypeptide of any of embodiments 1-51, wherein the variant PD-L2 decreases IFN-gamma (interferon-gamma) expression relative to the unmodified PD-L2 in an in vitro T-cell assay.


54. The variant PD-L2 polypeptide of any of embodiments 1-53 that is deglycosylated.


55. An immunomodulatory protein, comprising the variant PD-L2 polypeptide of any of embodiments 1-54 linked, directly or indirectly via a linker, to a second polypeptide comprising an immunoglobulin superfamily (IgSF) domain of an IgSF family member.


56. The immunomodulatory protein of embodiment 55, wherein the IgSF domain is an affinity-modified IgSF domain, said affinity-modified IgSF domain comprising one or more amino acid modifications compared to the unmodified or wild-type IgSF domain of the IgSF family member.


57. The immunomodulatory protein of embodiment 56, wherein the affinity modified IgSF domain exhibits altered binding to one or more of its cognate binding partner(s) compared to the binding of the unmodified or wild-type IgSF domain of the IgSF family member to the same one or more cognate binding partner(s).


58. The immunomodulatory protein of embodiment 57, wherein the IgSF domain exhibits increased binding to one or more of its cognate binding partner(s) compared to the binding of the unmodified or wild-type IgSF domain to the same one or more cognate binding partner(s).


59. The immunomodulatory polypeptide of any one of embodiments 56-58, wherein the variant PD-L2 is a first PD-L2 variant and the IgSF domain of the second polypeptide is an IgSF domain from a second variant PD-L2 of any of embodiments 1-58, wherein the first and second PD-L2 variant are the same or different.


60. The immunomodulatory protein of any one of embodiments 55-59, wherein the variant PD-L2 polypeptide is capable of specifically binding to PD-1 or RGMb and the IgSF domain of the second polypeptide is capable of binding to a cognate binding partner other than one specifically bound by the PD-L2 variant polypeptide.


61. The immunomodulatory protein of any of embodiments 55-60, wherein the IgSF domain is from a member of the B7 family.


62. The immunomodulatory protein of any of embodiments 55-60, wherein the IgSF domain is a tumor-localizing moiety that binds to a ligand expressed on a tumor or is an inflammatory-localizing moiety that binds to a ligand expressed on a cell or tissue of an inflammatory environment.


63. The immunomodulatory protein of embodiment 62, wherein the ligand is B7H6.


64. The immunomodulatory protein of embodiment 62 or embodiment 63, wherein the IgSF domain is from NKp30.


65. The immunomodulatory protein of any of embodiments 55-64, wherein the IgSF domain or affinity-modified IgSF domain thereof, optionally of the second or third polypeptide, is or comprises an IgV domain.


66. The immunomodulatory protein of any of embodiments 55-65, wherein the variant PD-L2 polypeptide is or comprises an IgV domain.


67. The immunomodulatory protein of any of embodiments 55-66, wherein the immunomodulatory protein further comprises a multimerization domain linked to at least one of the variant PD-L2 polypeptide or the second polypeptide, optionally wherein the multimerization domain is an Fc domain or a variant thereof with reduced effector function.


68. The immunomodulatory protein of any embodiments 55-67, wherein the IgSF domain of the second polypeptide is an IgSF domain of a ligand that binds to an inhibitory receptor, or is an affinity-modified IgSF domain thereof, optionally wherein the affinity-modified IgSF domain exhibits increased binding affinity and/or binding selectivity for the inhibitory receptor compared to binding of the unmodified IgSF domain to the same inhibitory receptor.


69. The immunomodulatory protein of embodiment 68, wherein:


the inhibitory receptor is TIGIT or CTLA-4; or


the ligand of the inhibitory receptor is CD155, CD112, or CD80.


70. The immunomodulatory protein of any of embodiments 55-69, wherein the second polypeptide is selected from:


(i) a wildtype CD155 comprising an IgSF set forth in any of SEQ ID NOS: 47, 344, or 387, or a variant CD155 polypeptide comprising an IgSF domain set forth in any of SEQ ID NOS: 345-386, 388-699, 1527-1736;


(ii) a wildtype CD112 comprising an IgSF domain set forth in any of SEQ ID NOS: 48, 700, or 795, or a variant CD112 polypeptide comprising an IgSF domain set forth in any of SEQ ID NOS: 701-794, 796-965, 1455-1526;


(iii) a wildtype CD80 comprising an IgSF set forth in any of SEQ ID NOS:28, 1039, or 2039, or a variant CD80 polypeptide comprising an IgSF domain set forth in any of SEQ ID NOS: 966-998, 1000-1038, 1040-1072, 1074-1112, 1114-1146, 1147-1186;


(iv) a wildtype PD-L1 comprising an IgSF set forth in any of SEQ ID NOS: 30, 1812, 1258, or 1454, or a variant PD-L1 polypeptide comprising an IgSF domain set forth in any of SEQ ID NOS:1259-1453, 1743-1811, 1813-2021;


(v) a sequence of amino acids that exhibits at least 95% sequence identity to any of the SEQ ID NOS in (i)-(iv) and that comprises the amino acid modifications, optionally amino acid substitutions, insertions and/or deletions thereof; or


(vi) a specific binding fragment of any of (i)-(v).


71. The immunomodulatory protein of any of embodiments 55-70, further comprising a third polypeptide comprising a wild-type IgSF domain or a variant or affinity-modified IgSF domain thereof, said affinity-modified IgSF domain comprising one or more amino acid modifications compared to the unmodified or wild-type IgSF domain of the IgSF family member, wherein:


the third polypeptide is the same as the first and/or second polypeptide; or


the third polypeptide is different from the first and/or second polypeptide.


72. The immunomodulatory protein of embodiment 71, wherein the IgSF domain of the third polypeptide is an affinity-modified IgSF domain comprising:


(i) a wildtype CD155 comprising an IgSF set forth in any of SEQ ID NOS: 47, 344, or 387, or a variant CD155 polypeptide comprising an IgSF domain set forth in any of SEQ ID NOS: 345-386, 388-699, 1527-1736;


(ii) a wildtype CD112 comprising an IgSF domain set forth in any of SEQ ID NOS: 48, 700, or 795, or a variant CD112 polypeptide comprising an IgSF domain set forth in any of SEQ ID NOS: 701-794, 796-965, 1455-1526;


(iii) a wildtype CD80 comprising an IgSF set forth in any of SEQ ID NOS:28, 1039, or 2039, or a variant CD80 polypeptide comprising an IgSF domain set forth in any of SEQ ID NOS: 966-998, 1000-1038, 1040-1072, 1074-1112, 1114-1146, 1147-1186;


(iv) a wildtype PD-L1 comprising an IgSF set forth in any of SEQ ID NOS: 30, 1812, 1258, or 1454, or a variant PD-L1 polypeptide comprising an IgSF domain set forth in any of SEQ ID NOS:1259-1453, 1743-1811, 1813-2021;


(v) a sequence of amino acids that exhibits at least 95% sequence identity to any of the SEQ ID NOS in (i)-(iv) and that comprises the amino acid modifications, optionally amino acid substitutions, insertions and/or deletions thereof; or


(vi) a specific binding fragment of any of (i)-(v).


73. The immunomodulatory protein of 70-72, further comprising at least one additional polypeptide comprising an IgSF domain of an IgSF family member or an affinity-modified IgSF domain thereof, said affinity-modified IgSF domain comprising one or more amino acid modifications compared to the binding of the unmodified or wild-type IgSF domain of the IgSF family member.


74. The immunomodulatory protein of any of embodiments 71-73, wherein the immunomodulatory protein further comprises a multimerization domain linked to at least one of the variant PD-L2 polypeptide, the second polypeptide and/or the third polypeptide, optionally wherein the multimerization domain is an Fc domain or a variant thereof with reduced effector function.


75. The immunomodulatory protein of any of embodiments 67-74, wherein the multimerization domain promotes heterodimer formation.


76. An immunomodulatory protein comprising a first variant PD-L2 polypeptide of any of embodiments 40-47 in which the multimerization domain is a first multimerization domain and a second variant PD-L2 polypeptide of any of embodiments 40-47 in which the multimerization domain is a second multimerization domain, wherein the first and second multimerization domains interact to form a multimer comprising the first and second variant PD-L2 polypeptide, optionally wherein the first and second variant PD-L2 polypeptides are the same.


77. An immunomodulatory protein comprising the immunomodulatory protein of any of embodiments 67-75, wherein the multimerization domain is a first multimerization domain and interacts with a second multimerization domain to form a multimer comprising the immunomodulatory protein.


78. The immunomodulatory protein of embodiment 77, wherein the immunomodulatory protein is a first immunomodulatory protein and a second immunomodulatory protein is linked directly or indirectly via a linker to the second multimerization domain, wherein the multimer comprises the first and second immunomodulatory protein.


79. The immunomodulatory protein of embodiment 78, wherein the second immunomodulatory protein is an immunomodulatory protein of any of caims 67-75, wherein the multimerization domain is the second multimerization domain.


80. The immunomodulatory protein of any of embodiments 76-79, wherein the multimer is a dimer.


81. The immunomodulatory protein of any of embodiments 76-80 that is a homodimer, optionally wherein the first and second multimerization domain is the same.


82. The immunomodulatory protein of any of embodiments 77-81, wherein the second polypeptide is a variant CD155 polypeptide and the first and/or second immunomodulatory protein comprises the sequence set forth in any of SEQ ID NOS: 1191-1196, or a sequence of amino acids that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% sequence identity to any of SEQ ID NOS: 1191-1196.


83. The immunomodulatory protein of any of embodiments 76-80 that is a heterodimer, optionally wherein the first and second multimerization domain are different and/or are capable of interacting to mediate heterodimer formation.


84. The immunomodulatory protein of any of embodiments 77-80 and 83, wherein the second polypeptide is a variant CD155 polypeptide and:


the first or second immunomodulatory protein comprises the sequence set forth in any of SEQ ID NOS: 1197, 1198, 1199, 1200, 1201, 1203 or a sequence of amino acids that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% sequence identity to any of SEQ ID NOS: 1197, 1198, 1199, 1200, 1201 or 1203; and


the other of the first or second immunomodulatory protein comprises the sequence set forth in any of SEQ ID NOS: 1188, 1190, 1202 or 1204, or a sequence of amino acids that exhibits at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% sequence identity to any of SEQ ID NOS: 1188, 1190, 1202 or 1204.


85. The immunomodulatory protein of any of embodiments 76-84, wherein the first and/or second multimerization domain is an Fc domain or a variant thereof with reduced effector function, optionally wherein:


the Fc domain is of an immunoglobulin protein that is human and/or the Fc region is human, optionally wherein the Fc region is of an immunoglobulin G1 (IgG1) or an immunoglobulin G2 (IgG2), optionally set forth in SEQ ID NO:211 or SEQ ID NO:212; or the variant Fc domain comprises one or more amino acid substitutions in a wildtype Fc region, optionally wherein the reduced effector function is reduced compared to a wildtype Fc region, optionally wherein the wildtype human Fc is of human IgG1.


86. The immunomodulatory protein of any of embodiments 76-85, wherein the first and second multimerization domain is the same or different.


87. The immunomodulatory protein of any of embodiments 65-75, 85 and 86, wherein the variant Fc region comprises:


the amino acid substitutions E233P, L234A, L234V, L235A, L235E, G236del, G237A, S267K, or N297G, with residue numbering according to the EU index of Kabat; or


the amino acid substitutions R292C/N297G/V302C or L234A/L235E/G237A, with residue numbering according to the EU index of Kabat.


88. The immunomodulatory protein of any of embodiments 65-75 and 85-87, wherein the Fc region or variant Fc region comprises the amino acid substitution C220S, with residue numbering according to the EU index of Kabat.


89. The immunomodulatory protein of any of embodiments 65-75 and 85-88, wherein the Fc region or variant Fc region comprises K447del, with residue numbering according to the EU index of Kabat.


90. A conjugate, comprising a variant PD-L2 of any of embodiments 1-54 or an immunomodulatory protein of any of embodiments 55-89 linked to a moiety.


91. The conjugate of embodiment 90, wherein the moiety is a targeting moiety that specifically binds to a molecule on the surface of a cell.


92. The conjugate of embodiment 91, wherein the targeting moiety specifically binds to a molecule on the surface of an immune cell, optionally wherein the immune cell is an antigen presenting cell or a lymphocyte.


93. The conjugate of embodiment 91, wherein the targeting moiety is a tumor-localizing moiety that binds to a molecule on the surface of a tumor.


94. The conjugate of any of embodiments 90-93, wherein the moiety is a protein, a peptide, nucleic acid, small molecule or nanoparticle.


95. The conjugate of any of embodiments 90-94, wherein the moiety is an antibody or antigen-binding fragment.


96. The conjugate of any of embodiments 90-95, wherein the conjugate is divalent, tetravalent, hexavalent or octavalent.


97. The conjugate of any of embodiments 90-96 that is a fusion protein.


98. A nucleic acid molecule(s), encoding a variant PD-L2 polypeptide of any of embodiments 1-59, an immunomodulatory protein of any of embodiments 55-89 or a conjugate that is a fusion protein of any of embodiments 90-97.


99. The nucleic acid molecule of embodiment 98 that is a synthetic nucleic acid.


100. The nucleic acid molecule of embodiment 98 or embodiment 99 that is cDNA.


101. A vector, comprising the nucleic acid molecule of any of embodiments 98-100.


102. The vector of embodiment 101 that is an expression vector.


103. The vector of embodiment 101 or embodiment 102, wherein the vector is a mammalian expression vector or a viral vector.


104. A cell, comprising the vector of any of embodiments 101-103.


105. The cell of embodiment 104 that is a mammalian cell.


106. The cell of embodiment 104 or embodiment 105 that is a human cell.


107. A method of producing a variant PD-L2 polypeptide or an immunomodulatory protein, comprising introducing the nucleic acid molecule of any of embodiments 98-100 or vector of any of embodiments 101-103 into a host cell under conditions to express the protein in the cell.


108. The method of embodiment 107, further comprising isolating or purifying the variant PD-L2 polypeptide or immunomodulatory protein from the cell.


109. A method of engineering a cell expressing a variant PD-L2 variant polypeptide, comprising introducing a nucleic acid molecule encoding the variant PD-L2 polypeptide of any of embodiments 1-54 into a host cell under conditions in which the polypeptide is expressed in the cell.


110. An engineered cell, expressing the variant PD-L2 polypeptide of any of embodiments 1-54, the immunomodulatory protein of any of embodiments 55-89, a conjugate that is a fusion protein of any of embodiments 90-97, the nucleic acid molecule of any of embodiments 98-100 or the vector of any of embodiments 101-102.


111. The engineered cell of embodiment 110, wherein the variant PD-L2 polypeptide or immunomodulatory protein is encoded by a nucleic acid comprising a sequence of nucleotides encoding a signal peptide.


112. The engineered cell of embodiment 110 or embodiment 111, wherein the variant PD-L2 polypeptide or immunomodulatory protein does not comprise a transmembrane domain and/or is not expressed on the surface of the cell.


113. The engineered cell of any of embodiments 110-112, wherein the variant PD-L2 polypeptide or immunomodulatory protein is secreted or is capable of being secreted from the engineered cell.


114. The engineered cell of embodiment 110 or embodiment 111, wherein the engineered cell comprises a variant PD-L2 polypeptide that comprises a transmembrane domain and/or is the transmembrane immunomodulatory protein of any of embodiments 48-54.


115. The engineered cell of embodiment 110, embodiment 111 or embodiment 114, wherein the variant PD-L2 polypeptide is expressed on the surface of the cell.


116. The engineered cell of any of embodiments 110-115, wherein the cell is an immune cell.


117. The engineered cell of embodiment 116, wherein the immune cell is an antigen presenting cell (APC) or a lymphocyte.


118. The engineered cell of any of embodiments 110-117, wherein the cell is a lymphocyte and the lymphocyte is a T cell.


119. The engineered cell of embodiment 118, wherein the cell is an APC and the APC is an artificial APC.


120. The engineered cell of any of embodiments 110-119 that is a primary cell.


121. The engineered cell of any of embodiments 110-120, wherein the cell is a mammalian cell.


122. The engineered cell of any of embodiments 110-121, wherein the cell is a human cell.


123. The engineered cell of any of embodiments 110-122, wherein the cell further comprises a chimeric antigen receptor (CAR) or an engineered T-cell receptor.


124. An infectious agent, comprising a nucleic acid molecule encoding a variant PD-L2 polypeptide of any of embodiments 1-54, an immunomodulatory polypeptide of any of embodiments 55-89 or a conjugate that is a fusion protein of any of claims 90-97.


125. The infectious agent of embodiment 124, wherein the encoded variant PD-L2 polypeptide or immunomodulatory polypeptide does not comprise a transmembrane domain and/or is not expressed on the surface of a cell in which it is expressed.


126. The infectious agent of embodiment 124 or embodiment 125, wherein the encoded variant PD-L2 polypeptide or immunomodulatory polypeptide is secreted or is capable of being secreted from a cell in which it is expressed.


127. The infectious agent of embodiment 124, wherein the encoded variant PD-L2 polypeptide comprises a transmembrane domain.


128. The infectious agent of embodiment 124 or embodiment 127, wherein the encoded variant PD-L2 polypeptide is expressed on the surface of a cell in which it is expressed.


129. The infectious agent of any of embodiments 124-128, wherein the infectious agent is a bacterium or a virus.


130. The infectious agent of embodiment 129, wherein the infectious agent is a virus and the virus is an oncolytic virus.


131. The infectious agent of embodiment 130, wherein the oncolytic virus is an adenovirus, adeno-associated virus, herpes virus, Herpes Simplex Virus, Vesticular Stomatic virus, Reovirus, Newcastle Disease virus, parvovirus, measles virus, vesticular stomatitis virus (VSV), Coxsackie virus or a Vaccinia virus.


132. The infectious agent of embodiment 130 or embodiment 131, wherein the virus specifically targets dendritic cells (DCs) and/or is dendritic cell-tropic.


133. The infectious agent of embodiment 132, wherein the virus is a lentiviral vector that is pseudotyped with a modified Sindbis virus envelope product.


134. The infectious agent of any of embodiments 124-133, further comprising a nucleic acid molecule encoding a further gene product that results in death of a target cell or that can augment or boost an immune response.


135. The infectious agent of embodiment 134, wherein the further gene product is selected from an anticancer agent, anti-metastatic agent, an antiangiogenic agent, an immunomodulatory molecule, an immune checkpoint inhibitor, an antibody, a cytokine, a growth factor, an antigen, a cytotoxic gene product, a pro-apoptotic gene product, an anti-apoptotic gene product, a cell matrix degradative gene, genes for tissue regeneration or a reprogramming human somatic cells to pluripotency.


136. A pharmaceutical composition, comprising the variant PD-L2 polypeptide of any of embodiments 1-54, an immunomodulatory protein of any of embodiments 55-89, a conjugate of any of embodiments 90-97 or an engineered cell of any of embodiments 110-123 or an infectious agent of any of embodiments 124-135.


137. The pharmaceutical composition of embodiment 136, comprising a pharmaceutically acceptable excipient.


138. The pharmaceutical composition of embodiment 136 or 137, wherein the pharmaceutical composition is sterile.


139. An article of manufacture comprising the pharmaceutical composition of any of embodiments 136-138 in a vial.


140. The article of manufacture of embodiment 139, wherein the vial is sealed. 141. A kit comprising the pharmaceutical composition of any of embodiments 136-138, and instructions for use.


142. A kit comprising the article of manufacture according to embodiment 139 and 140, and instructions for use.


143. A method of modulating an immune response in a subject, comprising administering the pharmaceutical composition of any of embodiments 136-138 to the subject.


144. A method of modulating an immune response in a subject, comprising administering the engineered cells of any of embodiments 110-123.


145. The method of embodiment 144, wherein the engineered cells are autologous to the subject.


146. The method of embodiment 144, wherein the engineered cells are allogenic to the subject.


147. The method of any of embodiments 143-146, wherein modulating the immune response treats a disease or condition in the subject.


148. The method of any of embodiments 143-147, wherein the immune response is increased.


149. The method of any of embodiments 143-148, wherein a variant PD-L2 polypeptide or immunomodulatory protein that is soluble, optionally that lacks a PD-L2 transmembrane and intracellular signaling domain, is administered to the subject.


150. The method of any of embodiments 143-149, wherein the variant polypeptide or immunomodulatory protein is an Fc fusion protein.


151. The method of any of embodiments 143 and 148-150, wherein a variant PD-L2 polypeptide of any of embodiments 1-54, or the immunomodulatory protein of any of embodiments 55-89 is administered to the subject.


152. The method of any of embodiments 143-149 wherein an engineered cell comprising a secretable variant PD-L2 polypeptide is administered to the subject.


153. The method of any of embodiments 143 and 148-152, wherein an engineered cell of any of embodiments 98-101 and 104-111 is administered to the subject.


154. The method of any of embodiments 143, 147 and 148, wherein an infectious agent encoding a variant PD-L2 polypeptide that is a secretable immunomodulatory protein is administered to the subject, optionally under conditions in which the infectious agent infects a tumor cell or immune cell and the secretable immunomodulatory protein is secreted from the infected cell.


155. The method of any of embodiments 143-154, wherein the disease or condition is a tumor or cancer.


156. The method of any one of embodiments 143-155, wherein the disease or condition is selected from melanoma, lung cancer, bladder cancer, a hematological malignancy, liver cancer, brain cancer, renal cancer, breast cancer, pancreatic cancer, colorectal cancer, spleen cancer, prostate cancer, testicular cancer, ovarian cancer, uterine cancer, gastric carcinoma, a musculoskeletal cancer, a head and neck cancer, a gastrointestinal cancer, a germ cell cancer, or an endocrine and neuroendocrine cancer.


157. The method of any of embodiments 143-147, wherein the immune response is decreased.


158. The method of any of embodiments 143-147 and 157, wherein an immunomodulatory protein or conjugate comprising a variant PD-L2 polypeptide linked to an IgSF domain or a moiety that localizes to a cell or tissue of an inflammatory environment is administered to the subject.


159. The method of embodiment 158, wherein the binding molecule comprises an antibody or an antigen-binding fragment thereof or comprises a wild-type IgSF domain or variant thereof.


160. The method of any of embodiments 143-147 and 157-159, wherein the immunomodulatory protein of any of embodiments 57-77 or the conjugate of any of embodiments 90-97 is administered to the subject.


161. The method of any of embodiments 143-147 and 157, wherein a variant PD-L2 polypeptide that is a transmembrane immunomodulatory protein is administered to the subject.


162. The method of any of embodiments 144-147 and 157-161, wherein the engineered cell comprising a variant PD-L2 polypeptide that is a transmembrane immunomodulatory protein of any of embodiments 50-59 is administered to the subject.


163. The method of any of embodiments 143, 147 and 157, wherein an infectious agent encoding a variant PD-L2 polypeptide that is a transmembrane immunomodulatory protein is administered to the subject, optionally under conditions in which the infectious agent infects a tumor cell or immune cell and the transmembrane immunomodulatory protein is expressed on the surface of the infected cell.


164. The method of any of embodiments 143-147 and 157-163, wherein the disease or condition is an inflammatory or autoimmune disease or condition.


165. The method of any of embodiments 143-147 and 157-164 wherein the disease or condition is an Antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis, a vasculitis, an autoimmune skin disease, transplantation, a Rheumatic disease, an inflammatory gastrointestinal disease, an inflammatory eye disease, an inflammatory neurological disease, an inflammatory pulmonary disease, an inflammatory endocrine disease, or an autoimmune hematological disease.


166. The method of embodiment 164 or embodiment 165, wherein the disease or condition is selected from inflammatory bowel disease, transplant, Crohn's disease, ulcerative colitis, multiple sclerosis, asthma, rheumatoid arthritis, or psoriasis.


IX. EXAMPLES

The following examples are included for illustrative purposes only and are not intended to limit the scope of the invention.


Example 1
Generation of Mutant DNA Constructs of IgSF Domains

Example 1 describes the generation of mutant DNA constructs of human PD-L2 IgSF domains for translation and expression on the surface of yeast as yeast display libraries.


A. Degenerate Libraries


Constructs were generated based on a wildtype human PD-L2 sequence set forth in SEQ ID NO:115 containing the immunoglobulin-like V-type (IgV) domain as follows:

    • LFTVTVPKELYIIEHGSNVTLECNFDTGSHVNLGAITASLQKVENDTSPHRERATLLEE QLPLGKASFHIPQVQVRDEGQYQCIIIYGVAWDYKYLTLKVKA (SEQ ID NO:115)


For libraries that target specific residues for complete or partial randomization with degenerate codons, degenerate codons, such as specific mixed base sets to code for various amino acid substitutions, are generated using an algorithm at the URL:rosettadesign.med.unc.edu/SwiftLib/. In general, positions to mutate were chosen from direct crystal structure information for PDL2::PD1 complex (e.g. PDB: 3BP5). Alternatively, a homology model may be generated if structures of homologous protein complexes are unavailable. Using the structural information, a structure viewer (available at the URL: spdbv.vital-it.ch) can be used to identify contact or non-contact interface residues for mutagenesis with degenerate codons


The next step in library design can be the alignment of human, mouse, rat, and monkey PD-L2 sequences to identify which of the residues chosen for mutagenesis are conserved residues. Based on this analysis, conserved target residues can be mutated with degenerate codons that only specify conservative amino acid changes plus the wild-type residue. Residues that are not conserved can be mutated more aggressively, but also included the wild-type residue. Degenerate codons that also encoded the wild-type residue are deployed to avoid excessive mutagenesis of target protein. For the same reason, only up to 20 positions are targeted for mutagenesis for each library. Selection of residues for mutagenesis is focused on contact, such as target side chain residues that interact with the ligand, and non-contact interfacial residues that are within 6 Å of the binding surface with their side chains directed toward the ligand/counter structure.


To generate DNA encoding the targeted library, overlapping oligos of up to 80 nucleotides in length and containing degenerate codons at the residue positions targeted for mutagenesis, can be ordered from Integrated DNA Technologies (Coralville, USA). The oligonucleotides are dissolved in sterile water, mixed in equimolar ratios, heated to 95° C. for five minutes and slowly cooled to room temperature for annealing. IgV domain-specific oligonucleotide primers that anneal to the start and end of the IgV domain gene sequence are then used to generate a first PCR product. IgV domain-specific oligonucleotides which overlap by 40 bp with pBYDS03 cloning vector (Life Technologies USA), beyond and including the BamHI and KpnI cloning sites, are then used to amplify 10Ong of PCR product from the prior step to generate a total of at least 12 μg of DNA for every electroporation. Both PCR's were by polymerase chain reaction (PCR) using OneTaq 2× PCR Master Mix (New England Biolabs, USA). The second PCR products are purified using a PCR purification kit (Qiagen, Germany) and resuspended in sterile deionized water. Alternatively, Ultramers (Integrated DNA Technologies) of up to 200 bp in length can be used in conjunction with megaprimer PCR (www.ncbi.nlm.nih.gov/pmc/articles/PMC146891/pdf/253371.pdf) to generate larger stretches of degenerate codons that could not be as easily generated using multiple small overlapping primers. Following the generation of full length product using megaprimer PCR, the mutant IgV domain library is PCR amplified again using DNA primers containing 40 bp overlap region with the pBYDS03 cloning vector for homologous recombination into yeast.


To prepare for library insertion, pBYDS03 vector is digested with BamHI and KpnI restriction enzymes (New England Biolabs, USA) and the large vector fragment is gel-purified and dissolved in sterile, deionized water. Electroporation-ready DNA for the next step is generated by mixing 12 μg of library DNA insert with 4 μg of linearized vector in a total volume of 50 μL deionized and sterile water. An alternative method to generate targeted libraries, is to carry out site-directed mutagenesis (Multisite kit, Agilent, USA) of the target IgV domain with oligonucleotides containing degenerate codons. This approach can be used to generate sublibraries that only target a few specific stretches of DNA for mutagenesis. In these cases, sublibraries can be mixed before proceeding to the selection steps. In general, library sizes are in the range of 10E7 to 10E8 clones, except that sublibraries are only in the range of 10E4 to 10E5.


B. Random Libraries


Random libraries were also constructed to identify variants of the IgV domain of PD-L2 set forth in SEQ ID NO:115. DNA encoding the wild-type IgV domain was cloned between the BamHI and KpnI sites of the yeast display vector pBYDS03. The DNA was then mutagenized with the Genemorph II Kit (Agilent, USA) to generate an average of three to five amino acid changes per library variant. Mutagenized DNA was then amplified by the two-step PCR and further processed as described above for targeted libraries.


Example 2
Introduction of DNA Libraries into Yeast

Example 2 describes the introduction of PD-L2 DNA libraries into yeast.


To introduce library DNA into yeast, electroporation-competent cells of yeast strain BJ5464 (ATCC.org; ATCC number 208288) were prepared and electroporated on a Gene Pulser II (Biorad, USA) with the electroporation-ready DNA from the steps above essentially as described (Colby, D. W. et al. 2004 Methods Enzymology 388, 348-358). The only exception is that transformed cells were grown in non-inducing minimal selective SCD-Leu medium to accommodate the LEU2 selectable marker carried by modified plasmid pBYDS03. One liter of SCD-Leu media consists of 14.7 grams sodium citrate, 4.29 grams citric acid monohydrate, 20 grams dextrose, 6.7 grams yeast nitrogen base, and 1.6 grams yeast synthetic drop-out media supplement without leucine. The Medium was filter sterilized before use using a 0.22 vacuum filter device.


Library size was determined by plating serial dilutions of freshly recovered cells on SCD-Leu agar plates and then extrapolating library size from the number of single colonies from plating that generated at least 50 colonies per plate. In general, library sizes ranged from 10E8 to 10E9 transformants based on this dilution assay. The remainder of the electroporated culture was grown to saturation in SCD-Leu and cells from this culture were subcultured 1/100 into fresh SCD-Leu once more and grown to saturation to minimize the fraction of untransformed cells, and grown overnight and to allow for segregation of plasmid from cells that may contain two or more library variants. To maintain library diversity, this subculturing step was carried out using an inoculum that contained at least 10× more cells than the calculated library size. Cells from the second saturated culture were resuspended in fresh medium containing sterile 25% (weight/volume) glycerol to a density of 10E10/mL and frozen and stored at −80° C. (frozen library stock).


Example 3
Yeast Selection

Example 3 describes the selection of yeast expressing affinity modified variants of PD-L2.


A number of cells equal to at least 10 times the estimated library size were thawed from individual library stocks, suspended to 0.1×10E6 cells/mL in non-inducing SCD-Leu medium, and grown overnight. The next day, a number of cells equal to 10 times the library size were centrifuged at 2000 RPM for two minutes and resuspended to 0.5×10E6 cells/mL in inducing SCDG-Leu media. One liter of the SCDG-Leu induction media consists of 5.4 grams Na2HPO4, 8.56 grams of NaH2PO4·H2O, 20 grams galactose, 2.0 grams dextrose, 6.7 grams yeast nitrogen base, and 1.6 grams of yeast synthetic drop out media supplement without leucine dissolved in water and sterilized through a 0.22 μm membrane filter device. The culture was grown in induction medium for 1 day at room temperature to induce expression of library proteins on the yeast cell surface.


Cells were sorted two to three times using magnetic beads loaded with cognate ligand to reduce non-binders and enrich for all variant PD-L2 with the ability to bind their exogenous recombinant counter-structure proteins. This was then followed by one to two rounds of fluorescence activated cell sorting (FACS) using decreasing concentrations of exogenous counter-structure protein staining in each round to enrich the fraction of yeast cells that displays improved binders. Magnetic bead enrichment and selections by flow cytometry were carried out essentially as described in Miller, K. D. et al., Current Protocols in Cytometry 4.7.1-4.7.30, July 2008.


With PD-L2 libraries, target ligand proteins was rhPD-1.Fc (i.e., recombinant human PD-1-Fc fusion protein from R&D Systems, USA). Magnetic Protein A beads were obtained from New England Biolabs, USA. For two-color, flow cytometric sorting, a Bio-Rad S3e sorter was used. PD-L2 display levels were monitored with an anti-hemagglutinin antibody labeled with Alexafluor 488 (Life Technologies, USA). Ligand binding of Fc fusion proteins to rhPD-1.Fc was detected with rPhycoerythrin (PE) conjugated anti-human Ig specific goat Fab (Jackson ImmunoResearch, USA). Doublet yeast were gated out using forward scatter (FSC)/side scatter (SSC) parameters, and sort gates were based upon higher ligand binding detected in FL2 that possessed more limited tag expression binding in FL1.


Yeast outputs from the flow cytometric sorts were assayed for higher specific binding affinity. Sort output yeast were expanded and re-induced to express the particular IgSF affinity modified domain variants they encode. This population then can be compared to the parental, wild-type yeast strain, or any other selected outputs, such as the bead output yeast population, by flow cytometry.


For PD-L2, the second round FACS outputs (F2) were compared to parental for binding rPD-1.Fc by double staining each population with anti-HA (hemagglutinin) tag expression and the anti-human Fc-PE secondary to detect ligand binding.


Selected variant PD-L2 IgV domains were further formatted as fusion proteins and tested for binding and functional activity as described below.


Example 4
Reformatting Selection Outputs as Fc-Fusions and in Various Immunomodulatory Protein Types

Example 4 describes reformatting of selection outputs identified in Example 3 as immunomodulatory proteins containing an affinity modified (variant) immunoglobulin-like V-type (IgV) domain of PD-L2 fused to an Fc molecule (variant IgV domain-Fc fusion molecules).


Output cell pools from final flow cytometric PD-L2 sorts were grown to terminal density in SCD-Leu medium. Plasmid DNA from at least 10× the number of cells of each sort output was isolated using a yeast plasmid DNA isolation kit (Zymo Research, USA). For Fc fusions, PCR primers with added restriction sites suitable for cloning into the Fc fusion vector of choice were used to batch-amplify from the plasmid DNA preps the coding DNA for the mutant target IgV domains After restriction digestion, the PCR products were ligated into Fc fusion vector followed by heat shock transformation into E. coli strain XL1 Blue (Agilent, USA) or NEB5alpha (New England Biolabs) as directed by supplier. Alternatively, the outputs were PCR amplified with primers containing 40 bp overlap regions on either end with Fc fusion vector to carry out in vitro recombination using Gibson Assembly Mastermix (New England Biolabs, USA), which was subsequently used for heat shock transformation into E. coli strain NEB5alpha. Exemplary of an Fc fusion vector is pFUSE-hIgG1-Fc2 (InvivoGen, USA).


Dilutions of transformation reactions were plated on LB-agar containing 100 μg/mL carbenicillin (Teknova, USA) to isolate single colonies for selection. Up to 96 colonies from each transformation were then grown in 96 well plates to saturation overnight at 37° C. in LB-broth (Teknova cat #L8112) and a small aliquot from each well was submitted for DNA sequencing of the IgV domain insert in order to identify mutation(s) in all clones. Sample preparation for DNA sequencing was carried out using protocols provided by the service provider (Genewiz; South Plainfield, N.J.). After removal of sample for DNA sequencing, glycerol was then added to the remaining cultures for a final glycerol content of 25% and plates were stored at −20° C. for future use as master plates (see below). Alternatively, samples for DNA sequencing were generated by replica plating from grown liquid cultures onto solid agar plates using a disposable 96 well replicator (VWR, USA). These plates were incubated overnight to generate growth patches and the plates were submitted to Genewiz as specified by Genewiz.


After analysis of the Genewiz-generated DNA sequencing data, clones of interest were recovered from master plates and individually grown to saturation in liquid LB-broth containing 100 μg/mL carbenicillin (Teknova, USA) and cultures were then used for preparation of plasmid DNA of each clone using a standard kit such as the PureYield Plasmid Miniprep System (Promega, USA) or the MidiPlus kit (Qiagen). Identification of clones of interest from Genewiz sequencing data generally involved the following steps. First, DNA sequence data files were downloaded from the Genewiz web site. All sequences were then manually curated so that they start at the beginning of the IgV domain coding region. The curated sequences were then batch-translated using a suitable program available at the URL: www.ebi.ac.uk/Tools/st/emboss transeq/. The translated sequences were then aligned using a suitable program available at the URL: multalin.toulouse.inra.fr/multalin/multalin.html. Alternatively, Genewiz sequenced were processed to generate alignments using Ugene software (ugene.net).


Clones of interest were then identified from alignments using the following criteria: 1.) identical clone occurs at least two times in the alignment and 2.) a mutation occurs at least two times in the alignment and preferably in distinct clones. Clones that meet at least one of these criteria were assumed to be clones that have been enriched by the sorting process most likely due to improved binding.


To generate recombinant immunomodulatory proteins that are Fc fusion proteins containing an IgV domain of PD-L2 with at least one affinity-modified domain (e.g. variant PD-L2 IgV-Fc), the encoding DNA was generated to encode a protein as follows: variant (mutant) PD-L2 IgV domain followed by a linker of three alanines (AAA) followed by a human IgG1 Fc set forth in SEQ ID NO:1205 containing the mutations R292C, N297G and V302C by EU numbering (corresponding to R77C, N82G and V87C with reference to wild-type human IgG1 Fc set forth in SEQ ID NO: 211). Since the construct does not include any antibody light chains that can form a covalent bond with a cysteine, the human IgG1 Fc also contains replacement of the cysteine residues to a serine residue at position 220 (C220S) by EU numbering (corresponding to position 5 (C5S) with reference to the wild-type or unmodified Fc set forth in SEQ ID NO: 211).


Example 5
Expression and Purification of Fc-Fusions

Example 5 describes the high throughput expression and purification of Fc-fusion proteins containing variant IgV PD-L2 as described in the above Examples.


Recombinant variant Fc fusion proteins were produced from suspension-adapted human embryonic kidney (HEK) 293 cells with Expi293 expression system (Invitrogen, USA). 4 μg of each plasmid DNA from the previous step was added to 200 μL Opti-MEM (Invitrogen, USA) at the same time as 10.84, ExpiFectamine was separately added to another 200 μL Opti-MEM. After 5 minutes, the 200 μL of plasmid DNA was mixed with the 200 μL of ExpiFectamine and was further incubated for an additional 20 minutes before adding this mixture to cells. Ten million Expi293 cells were dispensed into separate wells of a sterile 10 mL, conical bottom, deep 24 well growth plate (Thomson Instrument Company, USA) in a volume 4 mL Expi293 media (Invitrogen, USA). Plates were shaken for 5 days at 120 RPM in a mammalian cell culture incubator set to 95% humidity and 8% CO2. Following a 5-day incubation, cells were pelleted and culture supernatants were retained.


Protein was purified from supernatants using a high throughput 96 well Filter Plate (Thomson Catalog number 931919), each well loaded with 604, of Mab SelectSure settled bead (GE Healthcare cat. no. 17543801). Protein was eluted with four consecutive 200 μL fractions of 50 mM Acetate pH3.3. Each fraction's pH was adjusted to above pH 5.0 with 44, 2M Tris pH 8.0. Fractions were pooled and quantitated using 280 nm absorbance measured by Nanodrop instrument (Thermo Fisher Scientific, USA), and protein purity was assessed by loading 5 μg of protein on NUPAGE pre-cast, polyacrylamide gels (Life Technologies, USA) under denaturing and non-reducing conditions and subsequent gel electrophoresis. Proteins were visualized in gel using standard Coomassie staining.


Example 6
Assessment of Binding of Affinity-Matured IgSF Domain-Containing Molecules

A. Binding to Cell-Expressed Counter Structures


This Example describes Fc-fusion binding studies of purified proteins from the above Examples to assess specificity and affinity of PD-L2 domain variant immunomodulatory proteins for the cognate binding partner.


Binding studies were carried out on transfected HEK293 cells generated to express the full-length mammalian surface ligands using Jurkat/IL-2 reporter cells (purchased from Promega Corp. USA) that were then transduced to stably express PD-1 (Jurkat/PD-1). For staining by flow cytometry, 100,000 Jurkat/PD-1 cells or negative control (Jurkat only) were plated in 96 well round bottom plates. Cells were spun down and resuspended in staining buffer (PBS (phosphate buffered saline), 1% BSA (bovine serum albumin), and 0.1% sodium azide) for 20 minutes to block non-specific binding. Afterwards, cells were centrifuged again and resuspended in 50 μL staining buffer containing 100 nM to 46 pM of each candidate PD-L2 variant Fc fusion protein. As controls, a full extracellular domain of wild-type PD-L2 (composed of one IgV and one IgC domain) fused to Fc (“Full length ECD of PD-L2”) and an IgV domain of wild-type PD-L2 (“wild type PD-L2 IgV”) or, in some cases, anti-PD-1 monoclonal antibody (nivolumab), were tested. Primary staining was performed on ice for 45 minutes, before washing cells twice in 150 μL staining buffer. PE-conjugated anti-human Fc (Jackson ImmunoResearch, USA) was diluted 1:150 in 50 μl staining buffer and added to cells and incubated another 30 minutes on ice. Secondary antibody was washed out twice, cells were fixed in 4% formaldehyde/PBS, and samples were analyzed on Intellicyt flow cytometer (Intellicyt Corp, USA).


Mean Fluorescence Intensity (MFI) was calculated and compared to wild type PD-L2 IgV with FlowJo Version 10 (FlowJo LLC, USA). Specifically, the binding activity as measured by the Mean Fluorescence Intensity (MFI) value for binding of 50 nM of each variant Fc-fusion molecule to Jurkat/PD-1 cells and the ratio of the MFI compared to the binding of the corresponding wild type (unmodified) PD-L2 IgV fusion molecule not containing the amino acid substitution(s) to PD-1 was determined.


B. ForteBio Octet Binding Assay


Protein-protein interactions between PD-1 and PD-L2 domain variant immunomodulatory proteins were further assessed using Fortebio binding assays. PD-1 was loaded individually onto anti-human capture sensors (ForteBio Octet AHC) and Fc fusions of full length wildtype (unmodified) PD-L2 IgV, full length ECD of PD-L2, full length ECD of PD-L1, or variant PD-L2 Fc-fusion molecules were bound to the PD-1 receptor at a single concentration of 100 nM. As a positive control, anti-PD-1 monoclonal antibody (nivolumab) was also assessed.


Loading response of anti-human capture sensors of each binding protein being tested with the variant IgV-Fc fusion molecule was determined.


C. Results


Results for the binding studies for exemplary tested variant PD-L2 IgV-Fc fusion molecules are shown in Table 10. Table 10 indicates amino acid substitutions in the IgV of the variant PD-L2 selected in the screen described above. In the Table and Figure, the exemplary amino acid substitutions and insertions in the IgV domain are designated by amino acid position number corresponding to amino acid positions in the respective reference unmodified PD-L2 extracellular domain (ECD) sequence set forth in SEQ ID NO:31. The amino acid position is indicated in the middle, with the corresponding unmodified (e.g. wild-type) amino acid listed before the number and the identified variant amino acid substitution (or inserted designated by “ins”) listed after the number. Column 2 sets forth the SEQ ID NO identifier for each variant IgV domain contained in the variant IgV-Fc fusion molecule.


As shown in Table 10, the selections resulted in the identification of a number of PD-L2 IgSF (e.g. IgV) domain variants that were affinity-modified to exhibit increased binding for PD-1 as determined by flow cytometry binding studies to Jurkat/PD-1 cells or by Fortebio binding analysis. FIG. 8 depicts the MFI for binding to Jurakt/PD-1 cells at various concentrations of PD-L2 variant Fc fusion protein. As shown in FIG. 8, the tested variants exhibit improved binding to Jurkat/PD-1 compared to PDL2-IgV, and to levels that were similar to anti-PD-1 monoclonal antibody (nivolumab).









TABLE 10







Variant PD-L2 selected against PD-1. Molecule sequence and binding data.












Binding to Jurkat/
Fortebio




PD-1 Cells
binding












SEQ

Fold increase
to PD-1-



ID
MFI
over wildtype
Fc



NO
at
PD-L2
Response


PD-L2 mutation(s)
(IgV)
50 nM
IgV-Fc
Units














H15Q
268
15998
1.63
0.007


N24D
269
1414
0.14
−0.039


E44D
270
2928
0.3
−0.006


V89D
271
3361
0.34
0.005


Q82R,V89D
272
44977
4.57
1.111


E59G,Q82R
273
12667
1.29
−0.028


S39I,V89D
274
26130
2.65
0.26


S67L,V89D
275
15991
1.62
0.608


S67L,I85F
276
529
0.05
−0.005


S67L,I86T
277
6833
0.69
0.141


H15Q,K65R
278
13497
1.37
−0.001


H15Q,Q72H,V89D
279
12629
1.28
0.718


H15Q,S67L,R76G
280
47201
4.8
0.418


H15Q,R76G,185F
281
2941
0.3
−0.038


H15Q,T47A,Q82R
282
65174
6.62
0.194


H15Q,Q82R,V89D
283
49652
5.04
1.198


H15Q,C23S,I86T
284
830
0.08
−0.026


H15Q,S39I,I86T
285
1027
0.1
0.309


H15Q,R76G,I85F
286
1894
0.19
−0.006


E44D,V89D,W91R
287
614
0.06
−0.048


I13V,S67L,V89D
288
26200
2.66
1.42


H15Q,S67L,I86T
289
15952
1.62
0.988


I13V,H15Q,S67L,I86T
290
21570
2.19
1.391


I13V,H15Q,E44D,V89D
291
23958
2.43
1.399


I13V,S39I,E44D,Q82R,V89D
292
71423
7.26
0.697


I13V,E44D,Q82R,V89D
293
45191
4.59
1.283


Il3V,Q72H,R76G,I86T
294
10429
1.06
0.733


Il3V,H15Q,R76G,I85F
295
4736
0.48
−0.04


H15Q,S67L,R76G,I85F
297
2869
0.29
0.025









H15Q,S39I,R76G,V89D
298
Little or no protein produced











H15Q,T47A,Q72H,R76G,I86T
298
32103
3.26
0.512


H15Q,T47A,Q72H,R76G
299
16500
1.68
0.327


I13V,H15Q,T47A,Q72H,R76G
300
73412
7.46
0.896


H15Q,E44D,R76G,I85F
301
2885
0.29
−0.013


H15Q,S39I,S67L,V89D
302
45502
4.62
1.174


H15Q,N32D,S67L,V89D
303
25880
2.63
1.407


N32D,S67L,V89D
304
31753
3.23
1.155


H15Q,S67L,Q72H,R76G,V89D
305
40180
4.08
1.464


H15Q,Q72H,Q74R,R76G,I86T
306
4049
0.41
0.093


G28V,Q72H,R76G,I86T
307
5563
0.57
0.003


I13V,H15Q,S39I,E44D,S67L
308
63508
6.45
0.889


E44D,S67L,Q72H,Q82R,V89D
309
51467
5.23
1.061


H15Q,V89D
310
17672
1.8
0.31


H15Q,T47A
311
26578
2.7
0.016


I13V,H15Q,Q82R
312
76146
7.74
0.655


I13V,H15Q,V89D
313
28745
2.92
1.331


I13V,S67L,Q82R,V89D
314
58992
5.99
1.391


I13V,H15Q,Q82R,V89D
315
49523
5.03
1.419


H15Q,V31M,S67L,Q82R,V89D
316
67401
6.85
1.37


I13V,H15Q,T47A,Q82R
317
89126
9.05
0.652


I13V,H15Q,V31A,N45S,Q82R,V89D
318
68016
6.91
1.327


I13V, T20A, T47A, K65X*, Q82R, V89D
319
36743
3.73
0.092


H15Q,T47A,H69L,Q82R,V89D
320
65598
6.66
1.44


I13V,H15Q,T47A,H69L,R76G,V89D
321
54340
5.52
1.719


I12V,I13V,H15Q,T47A,Q82R,V89D
322
61207
6.22
1.453


I13V,H15Q,R76G,D77N,Q82R,V89D
323
33079
3.36
0.065


I13V,H15Q,T47A,R76G,V89D
324
53668
5.45
1.596


I13V,H15Q,T47A,Q82R,V89D
325
63320
6.43
1.418


I13V,H15Q,T47A,Q82R,V89D
325
60980
6.2
1.448


I13V,H15Q,I36V,T47A,S67L,V89D
327
52835
5.37
1.627


H15Q,T47A,K65R,S67L,Q82R,V89D
328
79692
8.1
1.453


H15Q,L33P,T47A,S67L,P71S,V89D
329
45726
4.65
1.467


I13V,H15Q,Q72H,R76G,I86T
330
24450
2.48
1.355


H15Q,T47A,S67L,Q82R,V89D
331
67962
6.9
1.479


F2L,H15Q,D46E,T47A,Q72H,R76G,Q82R,V89D
332
23039
2.34
1.045


I13V,H15Q,L33F,T47A,Q82R,V89D
333
62254
6.32
1.379


H15Q,N24S,T47A,Q72H,R76G,V89D
335
32077
3.26
0.4


I13V,H15Q,E44V,T47A,Q82R,V89D
336
61005
6.2
1.329


H15Q,N18D,T47A,Q72H,V73A,R76G,I86T,V89D
337
48317
4.91
0.475


I13V,H15Q,T37A,E44D,S48C,S67L,Q82R,V89D
338
47605
4.84
1.255


H15Q,L33H,S67L,R76G,Q82R,V89D
339
62326
6.33
1.507


I13V,H15Q,T47A,Q72H,R76G,I86T
340
49016
4.98
1.477


H15Q,S39I,E44D,Q72H,V75G,R76G,Q82R,V89D
341
43713
4.44
0.646


H15Q,T47A,S67L,R76G,Q82R,V89D
342
71897
7.3
1.539


I13V,H15Q,T47A,S67L,Q72H,R76G,Q82R,V89D
343
71755
7.29
1.536


Wild Type PD-L2 IgV
115
9843
1
−0.024


Full length ECD of PD-L2
31
2145
0.22
0.071


Full length ECD of PD-L1 (R&D Systems)
30
23769
2.41
1.263


Anti-PD-1 monoclonal antibody (nivolumab)

87002
8.84
0.899





*stop codon at indicated position






Example 7
Assessment of Activity of Affinity-Matured IgSF Domain-Containing Molecules with Mixed Lymphocyte Reaction (MLR)

This Example describes Fc-fusion variant protein bioactivity characterization in human primary T cell in vitro assays.


Soluble variant PD-L2 IgV-Fc bioactivity was tested in a human Mixed Lymphocyte Reaction (MLR). Human primary dendritic cells (DC) were generated by culturing monocytes isolated from PBMC (BenTech Bio, USA) in vitro for 7 days with 50 ng/mL rIL-4 (R&D Systems, USA) and 80 ng/mL rGM-CSF (R&D Systems, USA) in Ex-Vivo 15 media (Lonza, Switzerland). To fully induce DC maturation, lipopolysaccharide (LPS) (InvivoGen Corp., USA) was added at 100 ng/mL to the DC cultures on day 6 and cells were incubated for an additional 24 hours. Approximately, 10,000 matured DC and 100,000 purified allogeneic CD4+ T cells (BenTech Bio, USA) were co-cultured with several concentrations of variant PD-L2 IgV-Fc fusion proteins in 96 well round-bottom plates in 200 μL final volume of Ex-Vivo 15 media. Irrelevant human IgG or media only (designated “No Add”) were used as negative controls. As positive controls, either wildtype PDL2-Fc (full PD-L2 extracellular domain), wildtype PD-L2 IgV-Fc and or positive control anti-PD-1 monoclonal antibody (nivolumab) was assessed. On day 5, IFN-gamma secretion in culture supernatants was analyzed using the Human IFN-gamma Duoset ELISA kit (R&D Systems, USA). Optical density was measured on a BioTek Cytation Multimode Microplate Reader (BioTek Corp., USA) and quantitated against titrated rIFN-gamma standard included in the IFN-gamma Duo-set kit (R&D Systems, USA).


Results for the bioactivity studies for exemplary tested variant PD-L2 IgV-Fc are shown in Table 11, which sets forth the calculated levels of IFN-gamma in culture supernatants (pg/mL) at the tested concentration of variant IgV-Fc fusion molecule. Also shown in Table 11 is the fold increase in IFN-gamma levels of each variant IgV-Fc fusion molecule compared to the IFN-gamma levels of the corresponding unmodified (wildtype) IgV-Fc fusion molecule not containing the amino acid substitution(s). The variants are identified with reference to the amino acid substitutions in the IgV of PD-L2 with reference to positions corresponding to positions of the unmodified (wildtype) PD-L2 ECD sequence set forth in SEQ ID NO:31.


Exemplary variant PD-L2 IgV-Fc fusion proteins in Table 11 were further tested in an MLR at various increasing concentrations as indicated in FIG. 9 and FIG. 10. As shown in FIG. 9, exemplary variant PD-L2 IgV-Fc molecules exhibited improved activities to increase IFN-gamma production in an MLR assay. As shown in FIGS. 9 and 10, the exemplary variant PD-L2 IgV-Fc fusion molecules tested show comparable activity to nivolumab in the MLR assay.









TABLE 11







Bioactivity Data of PD-L2 variants selected against PD-1 in MLR.













Fold





increase




IFN
over



SEQ ID
gamma
wildtype



NO
levels
PD-L2


PD-L2 mutation(s)
(IgV)
pg/mL
IgV-Fc













H15Q
268
1817.1
1.32


N24D
269
1976.3
1.44


E44D
270
1499.4
1.09


V89D
271
1168.1
0.85


Q82R,V89D
272
1617
1.17


E59G,Q82R
273
1511.3
1.1


S39I,V89D
274
1314.5
0.95


S67L,V89D
275
1230.1
0.89


S67L,I85F
276
1281.9
0.93


S67L,I86T
277
1020.4
0.74


H15Q,K65R
278
1510.8
1.1


H15Q,Q72H,V89D
279
1272.2
0.92


H15Q,S67L,R76G
280
1426.2
1.04


H15Q,R76G,185F
281
1725.7
1.25


H15Q,T47A,Q82R
282
1317.9
0.96


H15Q,Q82R,V89D
283
1081.2
0.79


H15Q,C23S,I86T
284
1847.2
1.34


H15Q,S39I,I86T
285
1415.2
1.03


H15Q,R76G,I85F
286
1437.8
1.04


E44D,V89D,W91R
287
1560.1
1.13


I13V,S67L,V89D
288
867.5
0.63


H15Q,S67L,I86T
289
1034.2
0.75


I13V,H15Q,S67L,I86T
290
1014.4
0.74


I13V,H15Q,E44D,V89D
291
1384.2
1.01


I13V,S39I,E44D,Q82R,V89D
292
935.6
0.68


I13V,E44D,Q82R,V89D
293
1009.5
0.73


I13V,Q72H,R76G,I86T
294
1953
1.42


I13V,H15Q,R76G,I85F
295
1528.5
1.11


H15Q,S67L,R76G,I85F
297
1318.7
0.96


H15Q,T47A,Q72H,R76G,I86T
298
1599.6
1.16


H15Q,T47A,Q72H,R76G
299
1462.5
1.06


I13V,H15Q,T47A,Q72H,R76G
300
1469.8
1.07


H15Q,E44D,R76G,185F
301
1391.6
1.01


H15Q,S39I,S67L,V89D
302
1227
0.89


H15Q,N32D,S67L,V89D
303
1285.7
0.93


N32D,S67L,V89D
304
1194
0.87


H15Q,S67L,Q72H,R76G,V89D
305
1061.2
0.77


H15Q,Q72H,Q74R,R76G,I86T
306
933.8
0.68


G28V,Q72H,R76G,I86T
307
1781.6
1.29


I13V,H15Q,S391,E44D,S67L
308
1256.9
0.91


E44D,S67L,Q72H,Q82R,V89D
309
1281.4
0.93


H15Q,V89D
310
1495.4
1.09


H15Q,T47A
311
1637.2
1.19


I13V,H15Q,Q82R
312
1432.9
1.04


I13V,H15Q,V89D
313
1123
0.82


I13V,S67L,Q82R,V89D
314
1372.8
1


I13V,H15Q,Q82R,V89D
315
1596.6
1.16


H15Q,V31M,S67L,Q82R,V89D
316
1206.5
0.88


I13V,H15Q,T47A,Q82R
317
1703.3
1.24


I13V,H15Q,V31A,N45S,Q82R,V89D
318
1723.1
1.25


I13V, T20A, T47A, K65X, Q82R, V89D
319
1378.8
1


H15Q,T47A,H69L,Q82R,V89D
320
1732.5
1.26


I13V,H15Q,T47A,H69L,R76G,V89D
321
1075.5
0.78


I12V,I13V,H15Q,T47A,Q82R,V89D
322
1533.2
1.11


I13V,H15Q,R76G,D77N,Q82R,V89D
323
1187.9
0.86


I13V,H15Q,T47A,R76G,V89D
324
1253.7
0.91


I13V,H15Q,T47A,Q82R,V89D
325
1445.5
1.05


I13V,H15Q,T47A,Q82R,V89D
325
1737
1.26


I13V,H15Q,I36V,T47A,S67L,V89D
327
1357.4
0.99


H15Q,T47A,K65R,S67L,Q82R,V89D
328
1335.3
0.97


H15Q,L33P,T47A,S67L,P71S,V89D
329
1289.1
0.94


I13V,H15Q,Q72H,R76G,I86T
330
1221
0.89


H15Q,T47A,S67L,Q82R,V89D
331
1197.1
0.87


F2L,H15Q,D46E,T47A,Q72H,R76G,Q82R,V89D
332
1170.7
0.85


I13V,H15Q,L33F,T47A,Q82R,V89D
333
1468.4
1.07


I13V,H15Q,T47A,E58G,S67L,Q82R,V89D
334
836.1
0.61


H15Q,N24S,T47A,Q72H,R76G,V89D
335
1091.8
0.79


I13V,H15Q,E44V,T47A,Q82R,V89D
336
1270.5
0.92


H15Q,N18D,T47A,Q72H,V73A,R76G,I86T,V89D
337
1065.8
0.77


I13V,H15Q,T37A,E44D,S48C,S67L,Q82R,V89D
338
1751.7
1.27


H15Q,L33H,S67L,R76G,Q82R,V89D
339
1502
1.09


I13V,H15Q,T47A,Q72H,R76G,I86T
340
1088.1
0.79


H15Q,S39I,E44D,Q72H,V75G,R76G,Q82R,V89D
341
940.9
0.68


H15Q,T47A,S67L,R76G,Q82R,V89D
342
1097.8
0.8


I13V,H15Q,T47A,S67L,Q72H,R76G,Q82R,V89D
343
1559.6
1.13


Wild Type PD-L2 IgV
115
1376.8
1


Full length ECD of PD-L2
31
1173.2
0.85


Full length ECD of PD-L1
30
2190.9
1.59


Nivolumab (anti-PD-1)

418.9
0.3









Example 8
Additional Affinity Modified IgSF Domains

This examples describe the design, creation, and screening of additional affinity modified CD80 (B7-1), PD-L1, CD155 and CD112 and CD86 (B7-2) immunomodulatory proteins, which are other components of the immune synapse (IS) that have a demonstrated dual role in both immune activation and inhibition. Affinity-modified NKp30 variants also were generated and screened. These examples demonstrate that affinity modification of IgSF domains yields proteins that can act to both increase and decrease immunological activity. Various combinations of those domains fused in pairs (i.e., stacked) with a variant affinity modified PD-L2 to form a Type II immunomodulatory protein to achieve immunomodulatory activity.


Mutant DNA constructs of encoding a variant of the ECD domain of human CD80, or IgV domains of PD-L1, CD155 and CD112 for translation and expression as yeast display libraries were generated substantially as described in Example 1. Target libraries that target specific residues for complete or partial randomization with degenerate codons and/or random libraries were constructed to identify variants of the IgV of CD80 (SEQ ID NO:2039), variants of the ECD or IgV of PD-L1 (SEQ ID NO: 1454), variants of the IgV of CD155 (SEQ ID NO:387), and variants of the IgV of CD112 (SEQ ID NO:795) substantially as described in Example 1. Similar methods also were used to generate libraries of the IgC-like domain of NKp30 (SEQ ID NO:1238).


The degenerate or random library DNA was introduced into yeast substantially as described in Example 2 to generate yeast libraries. The libraries were used to select yeast expressing affinity modified variants of CD80, PD-L1, CD155, CD112, CD86 (B7-2), and NKp30 substantially as described in Example 3. Cells were processed to reduce non-binders and to enrich for CD80, PD-L1, CD155 or CD112, CD86 (B7-2), and NKp30 variants with the ability to bind their exogenous recombinant counter-structure proteins substantially as described in Example 3.


With CD80, CD86 and NKp30 libraries, target ligand proteins were sourced from R&D Systems (USA) as follows: human rCD28.Fc (i.e., recombinant CD28-Fc fusion protein), rPDL1.Fc, rCTLA4.Fc, and rB7H6.Fc. Two-color flow cytometry was performed substantially as described in Example 3. Yeast outputs from the flow cytometric sorts were assayed for higher specific binding affinity. Sort output yeast were expanded and re-induced to express the particular IgSF affinity modified domain variants they encode. This population then can be compared to the parental, wild-type yeast strain, or any other selected outputs, such as the bead output yeast population, by flow cytometry.


In the case of NKp30 yeast variants selected for binding to B7-H6, the F2 sort outputs gave MFI values of 533 when stained with 16.6 nM rB7H6.Fc, whereas the parental NKp30 strain MFI was measured at 90 when stained with the same concentration of rB7H6.Fc (6-fold improvement).


Among the NKp30 variants that were identified, was a variant that contained mutations L30V/A60V/S64P/S86G with reference to positions in the NKp30 extracellular domain corresponding to positions set forth in SEQ ID NO:54.


For CD80 variants provided in Table 12A-B, CD80 libraries consisted of positive selection with the desired counter structure CTLA4 and negative selection with the counter structure CD28.


For CD155 variants provided in Table 13A, CD155 libraries were selected against each of TIGIT, CD96, and CD226, separately. For CD155 variants provided in Table 13B-F, selection involved two positive selections with the desired counter structures TIGIT and CD96 followed by one negative selection with the counter structure CD226 to select away from CD226 and improve binding specificity of the variant CD155. Selection was performed essentially as described in Example 3 above except the concentrations of the counter structures (TIGIT/CD96) and selection stringency of the positive sorts were varied to optimize lead identification. The concentration of CD226 for the negative selection was kept at 100 nM.


For CD112 variants provided in Table 14A, CD112 libraries were selected against each of TIGIT, CD112R, and CD226, separately. For additional CD112 variants provided in Table 14B-14C, selection involved two positive selections with the desired counter structures TIGIT and CD112R followed by one negative selection with the counter structure CD226 to select away from CD226 and improve binding specificity of the variant CD112. Selection was performed essentially as described in Example 3 above except the concentrations of the counter structures (TIGIT/CD112R) and selection stringency of the positive sorts were varied to optimize lead identification. The concentration of CD226 for the negative selection was kept at 100 nM.


For PD-L1 variants provided in Table 15, yeast display targeted or random PD-L1 libraries were selected against PD-1. This was then followed by two to three rounds of flow cytometry sorting using exogenous counter-structure protein staining to enrich the fraction of yeast cells that displays improved binders. Alternatively, for PD-L1, selections were performed with human rCD80.Fc (i.e., human recombinant CD80 Fc fusion protein from R&D Systems, USA). Selections were carried out largely as described for PD-1. Magnetic bead enrichment and selections by flow cytometry are essentially as described in Miller K. D., Current Protocols in Cytometry 4.7.1-4.7.30, July 2008. PD-L1 variants in Table 15A-B were assessed for binding to cell-expressed counter structures. Additional PD-L1 variants identified in the screen as described above are set forth in Table 15C.


Exemplary selection outputs were reformatted as immunomodulatory proteins containing an affinity modified (variant) IgV of CD80, variant IgV of PD-L1, variant IgV of CD155, variant IgV of CD112, each fused to an Fc molecule (variant ECD-Fc fusion molecules or variant IgV-Fc fusion molecules) substantially as described in Example 4 and the Fc-fusion protein was expressed and purified substantially as described in Example 5.


Binding of exemplary IgSF domain variants to cell-expressed counter structures was then assessed substantially as described in Example 6. Cells expressing cognate binding partners were produced and binding studies and flow cytometry were carried out substantially as described in Example 6. In addition, the bioactivity of the Fc-fusion variant protein was characterized by either mixed lymphocyte reaction (MLR) or anti-CD3 coimmobilization assay substantially as described in Example 6.


As above, for each Table, the exemplary amino acid substitutions are designated by amino acid position number corresponding to the respective reference unmodified ECD sequence (Table 2). The amino acid position is indicated in the middle, with the corresponding unmodified (e.g. wild-type) amino acid listed before the number and the identified variant amino acid substitution listed (or inserted designated by a) after the number.


Also shown is the binding activity as measured by the Mean Fluorescence Intensity (MFI) value for binding of each variant Fc-fusion molecule to cells engineered to express the cognate counter structure ligand and the ratio of the MFI compared to the binding of the corresponding unmodified Fc fusion molecule not containing the amino acid substitution(s) to the same cell-expressed counter structure ligand. The functional activity of the variant Fc-fusion molecules to modulate the activity of T cells also is shown based on the calculated levels of IFN-gamma in culture supernatants (pg/mL) generated either i) with the indicated variant Fc fusion molecule coimmoblized with anti-CD3 or ii) with the indicated variant Fc fusion molecule in an MLR assay. The Tables also depict the ratio of IFN-gamma produced by each variant ECD-Fc or IgV-Fc compared to the corresponding unmodified ECD-Fc or IgV-Fc in the functional assays.


As shown in Tables 12A-15, the selections resulted in the identification of a number of PD-L1, CD155, CD112, and CD80 IgSF domain variants that were affinity-modified to exhibit increased binding for at least one, and in some cases more than one, cognate counter structure ligand. In addition, the results showed that affinity modification of the variant molecules also exhibited improved activities to both increase and decrease immunological activity depending on the format of the molecule.









TABLE 12A







Variant CD80 Binding to HEK293 Cells Transfected with CTLA4, CD28 or PD-L1














CTLA4
CD28
PD-L1

















SEQ ID
MFI at
Fold
MFI
Fold
MFI at
Fold




NO
66.6
change
at 66.6
change
22.2
change
Ratio of


CD80 mutation(s)
(IgV)
nM
to WT
nM
to WT
nM
to WT
CTLA4:CD28












L70P
1114
Not tested


I30F/L70P
1115
Not tested















Q27H/T41S/A71D
1116
368176
2.3
25051
1.01
24181
N/A
14.7


I30T/L70R
1117
2234
0.0
2596
0.10
5163
N/A
0.9


T13R/C16R/L70Q/A71D
1118
197357
1.2
16082
0.65
9516
N/A
12.3


T57I
1119
393810
2.4
23569
0.95
3375
N/A
16.7


M43I/C82R
1120
3638
0.0
3078
0.12
7405
N/A
1.2


V22L/M38V/M47T/A71D/
1121
175235
1.1
3027
0.12
6144
N/A
57.9


L85M










I30V/T57I/L70P/A71D/
1122
116085
0.7
10129
0.41
5886
N/A
11.5


A91T










V22I/L70M/A71D
1123
163825
1.0
22843
0.92
33404
N/A
7.2









N55D/L70P/E77G
1124
Not tested


T57A/I69T
1125
Not tested















N55D/K86M
1126
3539
0.0
3119
0.13
5091
N/A
1.1


L72P/T79I
1127
50176
0.3
3397
0.14
6023
N/A
14.8


L70P/F92S
1128
4035
0.0
2948
0.12
6173
N/A
1.4


T79P
1129
2005
0.0
2665
0.11
4412
N/A
0.8


E35D/M47I/L65P/D90N
1130
4411
0.0
2526
0.10
4034
N/A
1.7


L25S/E35D/M47I/D90N
1131
61265
0.4
4845
0.20
20902
N/A
12.6


Q27X*/S44P/I67T/P74S/
1132
195637
1.2
17524
0.71
17509
N/A
11.2


E81G/E95D










A71D
1133
220090
1.4
16785
0.68
29642
N/A
13.1


T13A/Q27X*/I61N/A71D
1134
195061
1.2
17519
0.71
21717
N/A
11.1


E81K/A91S
1135
98467
0.6
3309
0.13
44557
N/A
29.8


A12V/M47V/L70M
1136
81616
0.5
7400
0.30
31077
N/A
11.0


K34E/T41A/L72V
1137
88982
0.6
3755
0.15
35293
N/A
23.7


T41S/A71D/V84A
1138
103010
0.6
5573
0.22
83541
N/A
18.5


E35D/A71D
1139
106069
0.7
18206
0.73
40151
N/A
5.8


E35D/M47I
1140
353590
2.2
14350
0.58
149916
N/A
24.6


K36R/G78A
1141
11937
0.1
2611
0.11
5715
N/A
4.6


Q33E/T41A
1142
8292
0.1
2442
0.10
3958
N/A
3.4


M47V/N48H
1143
207012
1.3
14623
0.59
145529
N/A
14.2


M47L/V68A
1144
74238
0.5
13259
0.53
11223
N/A
5.6


S44P/A71D
1145
8839
0.1
2744
0.11
6309
N/A
3.2


Q27H/M43I/A71D/R73S
1146
136251
0.8
12391
0.50
8242
N/A
11.0


E35D/T57I/L70Q/A71D
1148
121901
0.8
21284
0.86
2419
N/A
5.7


M47I/E88D
1149
105192
0.7
7337
0.30
97695
N/A
14.3


M42I/I61V/A71D
1150
54478
0.3
6074
0.24
4226
N/A
9.0


P51A/A71D
1151
67256
0.4
4262
0.17
5532
N/A
15.8


H18Y/M47I/T57I/A71G
1152
136455
0.8
20081
0.81
13749
N/A
6.8


V20I/M47V/T57I/V84I
1153
183516
1.1
26922
1.08
3583
N/A
6.8


WT
2039
161423
1.0
24836
1.00
Not
N/A
6.5








tested







*Stop codon at indicated position













TABLE 12B







Variant CD80 Binding to HEK293 Cells Transfected with CTLA4, CD28 or PD-L1














CTLA4
CD28
PD-L1

















SEQ
MFI at
Fold
MFI at
Fold
MFI at
Fold
Ratio of



ID NO
66.6
change
66.6
change
22.2
change
CTLA4:


CD80 mutation(s)
(IgV)
nM
to WT
nM
to WT
nM
to WT
CD28


















V20I/M47V/A71D
1154
149937
7.23
15090
9.33
9710
5.48
9.9


A71D/L72V/E95K
1155
140306
6.77
6314
3.90
8417
4.75
22.2


V22L/E35G/A71D/L72P
1156
152588
7.36
8150
5.04
1403
0.79
18.7


E35D/A71D
1157
150330
7.25
14982
9.26
13781
7.77
10.0


E35D/I67L/A71D
1158
146087
7.04
11175
6.91
9354
5.28
13.1


T13R/M42V/M47I/A71D
1160
108900
5.25
16713
10.33
1869
1.05
6.5


E35D
1161
116494
5.62
3453
2.13
25492
14.38
33.7


E35D/M47I/L70M
1162
116531
5.62
14395
8.90
49131
27.71
8.1


E35D/A71/L72V
1163
134252
6.47
11634
7.19
13125
7.40
11.5


E35D/M43L/L70M
1164
102499
4.94
3112
1.92
40632
22.92
32.9


A26P/E35D/M43I/L85Q/E88D
1165
83139
4.01
5406
3.34
9506
5.36
15.4


E35D/D46V/L85Q
1166
85989
4.15
7510
4.64
38133
21.51
11.4


Q27L/E35D/M47I/T57I/L70Q/E88D
1167
59793
2.88
14011
8.66
1050
0.59
4.3


Q27H/E35G/A71D/L72P/T79I
1159
85117
4.10
10317
6.38
1452
0.82
8.3


M47V/I69F/A71D/V83I
1168
76944
3.71
15906
9.8.3
3399
1.92
4.8


E35D/T57A/A71D/L85Q
1169
85724
4.13
3383
2.09
1764
0.99
25.3


H18Y/A26T/E35D/A71D/L85Q
1170
70878
3.42
6487
4.01
8026
4.53
10.9


E35D/M47L
1171
82410
3.97
11508
7.11
58645
33.08
7.2


E23D/M42V/M43I/I58V/L70R
1172
37331
1.80
10910
6.74
2251
1.27
3.4


V68M/L70M/A71D/E95K
1173
56479
2.72
10541
6.51
38182
21.53
5.4


N55I/T57I/I69F
1174
2855
0.14
1901
1.17
14759
8.32
1.5


E35D/M43I/A71D
1175
63789
3.08
6369
3.94
27290
15.39
10.0


T41S/T57I/L70R
1176
59844
2.89
4902
3.03
19527
11.01
12.2


H18Y/A71D/L72P/E88V
1177
68391
3.30
8862
5.48
1085
0.61
7.7


V20I/A71D
1178
60323
2.91
10500
6.49
3551
2.00
5.7


E23G/A26S/E35D/T62N/A71D/L72V/L85M
1179
59025
2.85
5484
3.39
10662
6.01
10.8


A12T/E24D/E35D/D46V/I61V/L72P/E95V
1180
63738
3.07
7411
4.58
1221
0.69
8.6


V22L/E35D/M43L/A71G/D76H
1181
2970
0.14
1498
0.93
1851
1.04
2.0


E35G/K54E/A71D/L72P
1182
71899
3.47
3697
2.29
1575
0.89
19.4


L70Q/A71D
1183
45012
2.17
18615
11.50
1692
0.95
2.4


A26E/E35D/M47L/L85Q
1184
40325
1.94
2266
1.40
55548
31.33
17.8


D46E/A71D
1185
69674
3.36
16770
10.36
22777
12.85
4.2


Y31H/E35D/T41S/V68L/K93R/R94W
1186
3379
0.16
2446
1.51
18863
10.64
1.4


WT CD80 IgV Fc
2039
20739
1.00
1618
1.00
1773
1.00
12.8


WT CD80 ECD Fc

72506
3.50
3072
1.90
4418
2.49
23.6
















TABLE 13A







Variant CD155 selected against cognate binding partners. Molecule


sequences, binding data, and costimulatory bioactivity data.



















Anti-CD3








IFN-





TIGIT

Mock
gamma




CD226
tfxn
CD96
Expi293
(pg/mL)




tfxn
MFI
MFI
MFI
(Anti-CD3



SEQ
MFI
(TIGIT
(CD96
(Mock
IFN-



ID
(CD226
MFI
MFI
MFI
gamma


CD155
NO
MFI
parental
parental
parental
parental


mutations
(IgV)
parental
ratio)
ratio)
ratio)
ratio)
















P18S, P64S,
388
497825
247219
140065
3528
270.1


F91S

(133.7)
(91.1)
(45.4)
(1.2)
(0.7)


P18S, F91S,
389
26210
75176
10867
2130
364.2


L104P

(7.0)
(27.7)
(3.5)
(0.7)
(0.9)


L44P
390
581289
261931
152252
3414
277.6




(156.1)
(96.5)
(49.4)
(1.2)
(0.7)


A56V
391
455297
280265
161162
2601
548.2




(122.3)
(103.2)
(52.2)
(0.9)
(1.4)


P18L, L79V,
392
5135
4073
3279
2719
1241.5


F91S

(1.4)
(1.5)
(1.1)
(0.9)
(3.2)


P18S, F91S
393
408623
284190
147463
3348
760.6




(109.8)
(104.7)
(47.8)
(1.1)
(2.0)


P18T, F91S
394
401283
223985
157644
3065
814.7




(107.8)
(82.5)
(51.1)
(1.1)
(2.1)


P18T, S42P,
395
554105
223887
135395
3796
539.7


F91S

(148.8)
(82.5)
(43.9)
(1.3)
(1.4)


G7E, P18T,
396
12903
12984
7906
2671
275.9


Y30C, F91S

(3.5)
(4.8)
(2.6)
(0.9)
(0.7)


P18T, F91S,
397
438327
287315
167583
4012
307.2


G111D

(117.7)
(105.8)
(54.3)
(1.4)
(0.8)


P18S, F91P
398
4154
3220
2678
2816
365.7




(1.1)
(1.2)
(0.9)
(1.0)
(0.9)


P18T, F91S,
399
394546
298680
193122
2926
775.4


F108L

(106.0)
(110.0)
(62.6)
(1.0)
(2.0)


P18T, T45A,
400
435847
222044
191026
2948
1546.8


F91S

(117.1)
(81.8)
(61.9)
(1.0)
(4.0)


P18T, F91S,
401
3589
2942
2509
2390
1273.2


R94H

(1.0)
(1.1)
(0.8)
(0.8)
(3.3)


P18S, Y30C,
402
382352
276358
56934
3540
426.5


F91S

(102.7)
(101.8)
(18.5)
(1.2)
(1.1)


A81V, L83P
403
4169
2912
2616
2993
339.7




(1.1)
(1.1)
(0.8)
(1.0)
(0.9)


L88P
404
65120
74845
35280
2140
969.2




(17.5)
(27.6)
(11.4)
(0.7)
(2.5)


Wild type
387
3723
2715
3085
2913
389.6




(1.0)
(1.0)
(1.0)
(1.0)
(1.0)


R94H
405
18905
104013
11727
1663
372.6




(5.1)
(38.3)
(3.8)
(0.6)
(1.0)


A13E, P18S,
406
357808
179060
118570
2844
349.2


A56V, F91S

(96.1)
(66.0)
(38.4)
(1.0)
(0.9)


P18T, F91S,
407
38487
46313
22718
2070
1574.5


V115A

(10.3)
(17.1)
(7.4)
(0.7)
(4.0)


P18T, Q60K
408
238266
173730
154448
4778
427.2




(64.0)
(64.0)
(50.1)
(1.6)
(1.1)
















TABLE 13B







Additional CD155 Variants and Binding Data.














TIGIT
CD226
CD112R
CD96

















SEQ

Fold

Fold

Fold

Fold



ID

↑ to

↑ to

↑ to

↑ to


CD155
NO
MFI at
WT
MFI at
WT
MFI at
WT
MFI at
WT


Mutation(s)
(IgV)
100 nM
ECD
100 nM
ECD
100 nM
ECD
100 nM
ECD



















S52M
603
1865.3
0.00
1901.0
0.01
1553.4
0.87
1609.8
0.02


T45Q, S52L,
604
2287.0
0.01
2390.4
0.01
1735.1
0.97
1575.1
0.02


L104E, G111R











S42G
605
4837.5
0.01
2448.1
0.01
1815.4
1.02
1699.6
0.02


Q62F
606
2209.5
0.01
2572.1
0.01
2706.5
1.52
2760.7
0.03


S52Q
607
2288.1
0.01
2022.3
0.01
1790.1
1.00
1822.3
0.02


S42A, L104Q,
608
1923.7
0.00
1901.7
0.01
1815.1
1.02
1703.8
0.02


G111R











S42A, S52Q,
609
1807.5
0.00
2157.2
0.01
1894.4
1.06
1644.0
0.02


L104Q, G111R











S52W, L104E
610
1938.2
0.00
1905.6
0.01
2070.6
1.16
1629.5
0.02


S42C
611
1914.0
0.00
2096.1
0.01
1685.0
0.95
1592.4
0.02


S52W
612
1991.6
0.00
2037.3
0.01
1612.8
0.90
1712.9
0.02


S52M, L104Q
613
2666.6
0.01
2252.2
0.01
1706.0
0.96
1633.1
0.02


S42L, S52L,
614
2021.4
0.00
2643.8
0.02
1730.1
0.97
2318.7
0.02


Q62F, L104Q











S42W
615
2434.5
0.01
2133.4
0.01
2325.7
1.30
2555.4
0.03


S42Q
616
2073.5
0.00
2225.9
0.01
1905.1
1.07
2143.1
0.02


S52L
617
2224.8
0.01
2676.3
0.02
2038.6
1.14
2043.2
0.02


S52R
618
4395.4
0.01
3964.4
0.02
2741.7
1.54
4846.9
0.05


L104E
619
3135.4
0.01
2264.2
0.01
1803.5
1.01
1556.7
0.02


G111R
620
2082.7
0.00
2791.3
0.02
2470.9
1.39
3317.1
0.03


S52E
621
2655.4
0.01
2599.8
0.02
1904.9
1.07
1799.0
0.02


Q62Y
622
2528.6
0.01
2621.4
0.02
1918.4
1.08
1827.5
0.02


T45Q, S52M,
623
79498.2
0.19
143238.5
0.83
2600.6
1.46
6310.4
0.06


L104E











S42N, L104Q,
624
2432.1
0.01
2311.3
0.01
1847.4
1.04
1958.3
0.02


G111R











S52M, V57L
625
1760.7
0.00
2431.6
0.01
2006.9
1.13
1858.7
0.02


S42N, S52Q,
626
2402.7
0.01
2152.0
0.01
1855.0
1.04
1737.6
0.02


Q62F











S42A, S52L,
627
2262.7
0.01
1889.4
0.01
1783.2
1.00
1606.2
0.02


L104E, G111R











S42W, S52Q,
628
1961.4
0.00
2138.3
0.01
1844.9
1.03
1699.6
0.02


V57L, Q62Y











L104Q
629
10314.4
0.02
3791.4
0.02
2119.9
1.19
1542.6
0.02


S42L, S52Q,
630
1946.9
0.00
6474.3
0.04
1749.0
0.98
1702.2
0.02


L104E











S42C, S52L
631
1762.5
0.00
2147.3
0.01
1663.4
0.93
1484.7
0.01


S42W, S52R,
632
1918.8
0.00
2300.1
0.01
1824.6
1.02
1756.0
0.02


Q62Y, L104Q











T45Q, S52R,
633
121636.9
0.29
142381.2
0.82
2617.9
1.47
3748.2
0.04


L104E











S52R, Q62F,
634
2969.2
0.01
3171.6
0.02
1725.4
0.97
2362.3
0.02


L104Q, G111R











T45Q, S52L,
635
2857.7
0.01
5943.5
0.03
1496.8
0.84
1533.3
0.02


V57L, L104E











S52M, Q62Y
636
1926.6
0.00
2000.3
0.01
1771.6
0.99
1651.1
0.02


Q62F, L104E,
637
1966.4
0.00
2043.5
0.01
1701.9
0.95
1524.8
0.02


G111R











T45Q, S52Q
638
4812.8
0.01
5787.5
0.03
1765.6
0.99
2451.3
0.02


S52L, L104E
639
4317.8
0.01
2213.9
0.01
1756.9
0.99
1829.3
0.02


S42V, S52E
640
2055.0
0.00
2272.6
0.01
1808.0
1.01
2530.2
0.03


T45Q, S52R,
641
4092.3
0.01
2075.2
0.01
1793.6
1.01
2336.6
0.02


G111R











S42G, S52Q,
642
2010.1
0.00
2019.2
0.01
1706.4
0.96
1707.6
0.02


L104E, G111R











S42N, S52E,
643
1784.2
0.00
1743.6
0.01
1690.1
0.95
1538.7
0.02


V57L, L104E











Wildtype
387
1964.7
0.00
2317.1
0.01
2169.6
1.22
1893.4
0.02


S42C, S52M,
644
1861.0
0.00
2084.2
0.01
1592.3
0.89
1481.3
0.01


Q62F











S42L
645
1930.4
0.00
2187.2
0.01
1743.2
0.98
1618.4
0.02


Wildtype
387
2182.6
0.01
2374.5
0.01
1743.1
0.98
1680.4
0.02


S42A
646
1929.2
0.00
2188.6
0.01
1733.7
0.97
1623.6
0.02


S42G, S52L,
647
1924.3
0.00
2157.6
0.01
1661.3
0.93
1642.1
0.02


Q62F, L104Q











S42N
648
1817.4
0.00
1910.9
0.01
1699.7
0.95
1691.5
0.02


CD155 IgV Fc
387
4690
0.01
4690
0.03
2941
1.65
3272
0.03


Wildtype
47
423797
1.00
172839
1.00
1783
1.00
99037
1.00


CD155
(ECD)










ECD-Fc











Anti-human

1506.3
0.00
3774
0.02
1587
0.89
1618
0.02


Fc PE
















TABLE 13C







Additional C155 Variants and Binding Data.













TIGIT
CD226
CD96















SEQ
MFI
Fold
MFI
Fold
MFI
Fold



ID
at
Increase
at
Increase
at
Increase



NO
100
to WT
100
to WT
100
to WT


CD155 Mutation(s)
(IgV)
nM
ECD
nM
ECD
nM
ECD

















P18T, S65A, S67V, F91S
649
297843
1.99
351195
3.22
128180
1.68









P18F, T39A, T45Q, T61R,
650
Little to no protein produced














S65N, S67L, E73G, R78G









P18T, T45Q, T61R, S65N,
651
224682
1.50
270175
2.48
22820
0.30


S67L









P18F, S65A, S67V, F91S
652
534106
3.57
350410
3.21
144069
1.89









P18F, T45Q, T61R, S65N,
653
Little to no protein produced














S67L, F91S, L104P









P18S, L79P, L104M
654
342549
2.29
320823
2.94
107532
1.41


P18S, L104M
655
449066
3.00
295126
2.70
121266
1.59


L79P, L104M
656
3210
0.02
8323
0.08
2894
0.04


P18T, T45Q, L79P
657
542878
3.63
371498
3.40
193719
2.55


P18T, T45Q, T61R, S65H,
658
312337
2.09
225439
2.07
152903
2.01


S67H
















P18T, A81E
659
Little to no protein produced


P18S, D23Y, E37P, S52G,
660
Little to no protein produced














Q62M, G80S, A81P, G99Y,









S112N









A13R, D23Y, E37P, S42P,
661
4161
0.03
11673
0.11
5762
0.08


Q62Y, A81E
















A13R, D23Y, E37P, G99Y,
662
Little to no protein produced














S112N
















A13R, D23Y, E37P, Q62M,
663
Little to no protein produced














A77V, G80S, A81P, G99Y









P18L, E37S, Q62M, G80S,
664
5900
0.04
14642
0.13
3345
0.04


A81P, G99Y, S112N









P18S, L104T
665
321741
2.15
367470
3.37
108569
1.43


P18S, Q62H, L79Q, F91S
666
283357
1.89
324877
2.98
125541
1.65


P18S, F91S
393
222780
1.49
300049
2.75
48542
0.64









T45Q, S52K, Q62F, L104Q,
667
Little to no protein produced














G111R
















T45Q, S52Q, Q62Y, L104Q,
668
Little to no protein produced














G111R
















T45Q, S52Q, Q62Y, L104E,
669
Little to no protein produced














G111R
















V57A, T61M, S65W, S67A,
670
Little to no protein produced














E96D, L104T









P18L, V57T, T61S, S65Y,
671
278178
1.86
276870
2.54
121499
1.60


S67A, L104T









P18T, T45Q
672
326769
2.18
357515
3.28
92389
1.21









P18L, V57A, T61M, S65W,
673
Little to no protein produced














S67A, L104T









T61M, S65W, S67A, L104T
674
360915
2.41
417897
3.83
148954
1.96


P18S, V41A, S42G, T45G,
675
3821
0.03
11449
0.10
3087
0.04


L104N









P18H, S42G, T45I, S52T,
676
5066
0.03
177351
1.63
3700
0.05


G53R, S54H, V57L, H59E,









T61S, S65D, E68G, L104N









P18S, S42G, T45V, F58L,
677
14137
0.09
15175
0.14
15324
0.20


S67W, L104N









P18S, T45I, L104N
678
141745
0.95
298011
2.73
97246
1.28


P18S, S42G, T45G, L104N,
679
29387
0.20
117965
1.08
15884
0.21


V106A









P18H, H40R, S42G, T45I,
680
12335
0.08
14657
0.13
15779
0.21


S52T, G53R, S54H, V57L,









H59E, T61S, S65D, E68G,









L104Y, V106L, F108H
















E37V, S42G, T45G, L104N
681
Little to no protein produced














P18S, T45Q, L79P, L104T
682
206674
1.38
285512
2.62
87790
1.15


P18L, Q62R
683
66939
0.45
25063
0.23
10928
0.14









A13R, D23Y, E37P, S42L,
684
Little to no protein produced














S52G, Q62Y, A81E









P18L, H49R, L104T, D116N
685
167980
1.12
214677
1.97
62451
0.82









A13R, D23Y, E37P, Q62M,
686
Little to no protein produced














G80S, A81P, L104T









S65T, L104T
687
205942
1.38
187147
1.71
65207
0.86









A13R, D23Y, E37P, S52G,
688
Little to no protein produced














V57A, Q62M, K70E, L104T









P18L, A47V, Q62Y, E73D,
689
146142
0.98
248926
2.28
73956
0.97


L104T
















H40T, V41M, A47V, S52Q,
690
Little to no protein produced














Q62L, S65T, E73R, D97G,









E98S, L104T, D116N









P18L, S42P, T45Q, T61G,
691
153536
1.03
402503
3.69
53044
0.70


S65H, S67E, L104T, D116N
















P18S, H40T, V41M, A47V,
692
Little to no protein produced














S52Q, Q62L, S65T, E73R,









L104M, V106A
















H40T, V41M, A47V, S52Q,
693
Little to no protein produced














Q62L, S65T, E68G, E73R,









D97G, E98S, L104T
















T45Q, S52E, L104E
694
Little to no protein produced














T45Q, S52E, Q62F, L104E
695
132850
0.89
276434
2.53
14558
0.19


Wildtype CD155 ECD-Fc
47
149692
1.00
109137
1.00
76083
1.00



(ECD)








Anti-human Fc PE

2287
0.02
4799
0.04
2061
0.03
















TABLE 13D







Additional CD155 Variants and Binding Data.













TIGIT
CD226
CD96















SEQ
MFI
Fold

Fold
MFI
Fold



ID
at
Increase
MFI at
Increase
at
Increase



NO
100
to WT
100
to WT
100
to WT


CD155 Mutations
(IgV)
nM
IgV
nM
IgV
nM
IgV

















P18F, T26M, L44V,
696
117327
1.2
1613
0.1
1629
0.1


Q62K, L79P, F91S,









L104M, G111D









P18S, T45S, T61K,
697
124936
1.3
2114
0.1
2223
0.1


S65W, S67A, F91S,









G111R









P18S, L79P,
698
110512
1.1
18337
0.9
22793
1.3


L104M, T107M









P18S, S65W, S67A,
696
101726
1.0
1605
0.1
2571
0.1


M90V, V95A,









L104Q, G111R









Wildtype CD155-
47
98935
1.0
20029
1.0
17410
1.0


ECD
(ECD)






















TABLE 13E







Additional CD155 Variants and Binding Data.













TIGIT
CD226
CD96

















Fold

Fold

Fold



SEQ

Change

Change

Change



ID
MFI at
from
MFI at
from
MFI at
from



NO
11.1
CD155-
11.1
CD155-
11.1
CD155-


CD155 Mutations
(IgV)
nM
ECD
nM
ECD
nM
ECD

















P18S, A47G, L79P, F91S,
1550
56,409
1.19
1,191
0.08
25,362
1.49


L104M, T107A, R113W









P18T, D23G, S24A, N35D,
1551
128,536
2.72
987
0.06
3,497
0.20


H49L, L79P, F91S, L104M,









G111R









V9L, P18S, Q60R, V75L,
1552
125,329
2.65
986
0.06
959
0.06


L79P, R89K, F91S, L104E,









G111R
















P18S, H49R, E73D, L79P,
1553
Little to no protein produced














N85D, F91S, V95A,









L104M, G111R









V11A, P18S, L79P, F91S,
1554
48,246
1.02
974
0.06
923
0.05


L104M, G111R









V11A, P18S, S54R, Q60P,
1555
190,392
4.02
1,019
0.07
1,129
0.07


Q62K, L79P, N85D, F91S,









T107M









P18T, S52P, S65A, S67V,
1556
121,611
2.57
986
0.06
16,507
0.97


L79P, F91S, L104M,









G111R









P18T, M36T, L79P, F91S,
1557
150,015
3.17
1,029
0.07
2,514
0.15


G111R









D8G, P18S, M36I, V38A,
1558
79,333
1.68
1,026
0.07
2,313
0.14


H49Q, A76E, F91S,









L104M, T107A, R113W









P18S, S52P, S65A, S67V,
1559
23,766
0.50
1,004
0.07
1,080
0.06


L79P, F91S, L104M,









T107S, R113W









T15I, P18T, L79P, F91S,
1560
55,498
1.17
1,516
0.10
1,030
0.06


L104M, G111R









P18F, T26M, L44V, Q62K,
1561
213,640
4.51
991
0.06
1,276
0.07


L79P, E82D, F91S, L104M,









G111D









P18T, E37G, G53R, Q62K,
1562
251,288
5.31
2,001
0.13
45,878
2.69


L79P, F91S, E98D, L104M,









T107M









P18L, K70E, L79P, F91S,
1563
62,608
1.32
1,117
0.07
973
0.06


V95A, G111R









V9I, Q12K, P18F, S65A,
1564
81,932
1.73
803
0.05
68,295
4.00


S67V, L79P, L104T,









G111R, S112I









P18F, S65A, S67V, F91S,
1565
30,661
0.65
901
0.06
3,193
0.19


L104M, G111R









V9I, V10I, P18S, F20S,
1566
151,489
3.20
973
0.06
974
0.06


T45A, L79P, F91S, L104M,









F108Y, G111R, S112V









V9L, P18L, L79P, M90I,
1567
155,279
3.28
910
0.06
10,568
0.62


F91S, T102S, L104M,









G111R









P18C, T26M, L44V, M55I,
1568
137,521
2.91
973
0.06
111,085
6.51


Q62K, L79P, F91S, L104M,









T107M









V9I, P18T, D23G, L79P,
1569
151,426
3.20
897
0.06
2,725
0.16


F91S, G111R









P18F, L79P, M90L, F91S,
1570
125,639
2.66
917
0.06
3,939
0.23


V95A, L104M, G111R









P18F, L79P, M90L, F91S,
1570
115,156
2.43
1,073
0.07
2,464
0.14


V95A, L104M, G111R









P18T, M36T, S65A, S67E,
1571
10,616
0.22
1,130
0.07
963
0.06


L79Q, A81T, F91S, G111R









V9L, P18T, Q62R, L79P,
1572
195,111
4.12
835
0.05
1,497
0.09


F91S, L104M, G111R









CD155-ECD-Fc
47
47,319
1.00
15,421
1.00
17,067
1.00



(ECD)








Fc Control
1189
2,298
0.05
1,133
0.07
996
0.06
















TABLE 13F







Additional CD155 Variants and Binding Data.














TIGIT
CD226
CD112R
CD96



















Fold

Fold

Fold

Fold



SEQ

Change

Change

Change

Change



ID

from

from

from

from



NO
MFI at
CD155-
MFI at
CD155-
MFI at
CD155-
MFI at
CD155-


CD155 Mutations
(IgV)
25 nM
ECD
25 nM
ECD
25 nM
ECD
25 nM
ECD



















P18T, G19D, M36T, S54N,
1691
905
0.02
748
0.02
1276
1.56
726
0.01


L79P, L83Q, F91S, T107M,











F108Y











V9L, P18L, M55V, S69L,
1692
58656
1.34
11166
0.29
920
1.13
67364
1.39


L79P, A81E, F91S, T107M











P18F, H40Q, T61K, Q62K,
1693
108441
2.48
853
0.02
918
1.13
8035
0.17


L79P, F91S, L104M,











T107V











P18S, Q32R, Q62K, R78G,
1694
5772
0.13
701
0.02
843
1.03
831
0.02


L79P, F91S, T107A,











R113W











Q12H, P18T, L21S, G22S,
1695
1084
0.02
687
0.02
876
1.07
818
0.02


V57A, Q62R, L79P, F91S,











T107M











V9I, P18S, S24P, H49Q,
1696
69926
1.60
1089
0.03
1026
1.26
43856
0.90


F58Y, Q60R, Q62K, L79P,











F91S, T107M











P18T, W46C, H49R, S65A,
1697
918
0.02
640
0.02
803
0.98
717
0.01


S67V, A76T, L79P, S87T,











L104M











P18S, S42T, E51G, L79P,
1698
12630
0.29
707
0.02
857
1.05
1050
0.02


F91S, G92W, T107M











P18S, S42T, E51G, L79P,
1698
7476
0.17
851
0.02
935
1.15
924
0.02


F91S, G92W, T107M











V10F, T15S, P18L, R48Q,
1699
1168
0.03
792
0.02
901
1.10
998
0.02


L79P, F91S, T107M,











V115M











P18S, L21M, Y30F, N35D,
1700
1377
0.03
743
0.02
946
1.16
1033
0.02


R84W, F91S, T107M,











D116G











P18F, E51V, S54G, Q60R,
1701
46090
1.05
15701
0.41
1012
1.24
61814
1.27


L79Q, E82G, S87T, M90I,











F91S, G92R, T107M


















Q16H, P18F, F91S, T107M
1702
Little to no protein produced
















P18T, D23G, Q60R, S67L,
1703
64091
1.47
30931
0.81
874
1.07
108875
2.24


L79P, F91S, T107M,











V115A











D8G, V9I, V11A, P18T,
1704
52508
1.20
9483
0.25
817
1.00
97770
2.01


T26M, S52P, L79P, F91S,











G92A, T107L, V115A











V9I, P18F, A47E, G50S,
1705
55167
1.26
54341
1.43
752
0.92
102115
2.10


E68G, L79P, F91S, T107M


















P18S, M55I, Q62K, S69P,
1706
Little to no protein produced
















L79P, F91S, T107M











P18T, T39S, S52P, S54R,
1707
45927
1.05
744
0.02
1038
1.27
1225
0.03


L79P, F91S, T107M


















P18S, D23N, L79P, F91S,
1708
Little to no protein produced
















T107M, S114N











P18S, P34S, E51V, L79P,
1709
7917
0.18
769
0.02
853
1.04
892
0.02


F91S, G111R











P18S, H59N, V75A, L79P,
1710
800
0.02
676
0.02
915
1.12
759
0.02


A81T, F91S, L104M,











T107M











P18S, W46R, E68D, L79P,
1711
1359
0.03
717
0.02
798
0.98
737
0.02


F91S, T107M, R113G











V9L, P18F, T45A, S65A,
1712
130274
2.98
153569
4.04
812
1.00
85605
1.76


S67V, R78K, L79V, F91S,











T107M, S114T











P18T, M55L, T61R, L79P,
1713
133399
3.05
1906
0.05
827
1.01
57927
1.19


F91S, V106I, T107M











T15I, P18S, V33M, N35F,
1714
7550
0.17
1015
0.03
789
0.97
2709
0.06


T39S, M55L, R78S, L79P,











F91S, T107M











P18S, Q62K, K70E, L79P,
1715
1951
11173
0.26
691
0.02
735
0.90
0.04


F91S, G92E, R113W











P18F, F20I, T26M, A47V,
1716
136088
3.11
54026
1.42
1401
1.72
96629
1.99


E51K, L79P, F91S











P18T, D23A, Q60H, L79P,
1717
43795
1.00
98241
2.58
888
1.09
70891
1.46


M90V, F91S, T107M











P18S, D23G, C29R, N35D,
1718
1599
0.04
1030
0.03
1115
1.37
1944
0.04


E37G, M55I, Q62K, S65A,











S67G, R78G, L79P, F91S,











L104M, T107M, Q110R


















A13E, P18S, M36R, Q62K,
1719
Little to no protein produced
















S67T, L79P, N85D, F91S,











T107M











V9I, P18T, H49R, L79P,
1720
46375
1.06
76851
2.02
794
0.97
80210
1.65


N85D, F91S, L104T,











T107M











V9A, P18F, T61S, Q62L,
1721
26109
0.60
891
0.02
825
1.01
2633
0.05


L79P, F91S, G111R


















D8E, P18T, T61A, L79P,
1722
Little to no protein produced
















F91S, T107M











P18S, V41A, H49R, S54C,
1723
1098
0.03
830
0.02
876
1.07
1678
0.03


L79S, N85Y, L88P, F91S,











L104M, T107M











V11E, P18H, F20Y, V25E,
1724
979
0.02
846
0.02
844
1.03
928
0.02


N35S, H49R, L79P, F91S,











T107M, G111R











V11A, P18F, D23A, L79P,
1725
45249
1.04
913
0.02
830
1.02
33883
0.70


G80D, V95A, T107M











P18S, K70R, L79P, F91S,
1726
16180
0.37
793
0.02
854
1.05
1182
0.02


G111R











P18T, D23A, Q60H, L79P,
1717
175673
4.02
161958
4.26
879
1.08
50981
1.05


M90V, F91S, T107M











V9L, V11M, P18S, N35S,
1727
2999
0.07
2315
0.06
893
1.09
925
0.02


S54G, Q62K, L79P,











L104M, T107M, V115M











V9L, P18Y, V25A, V38G,
1728
138011
3.16
26015
0.68
919
1.13
17970
0.37


M55V, A77T, L79P, M90I,











F91S, L104M











V10G, P18T, L72Q, L79P,
1729
4253
0.10
1584
0.04
863
1.06
3643
0.07


F91S, T107M











P18S, H59R, A76G, R78S,
1730
130622
2.99
79435
2.09
1009
1.24
44493
0.91


L79P











V9A, P18S, M36T, S65G,
1731
92503
2.12
989
0.03
886
1.09
7850
0.16


L79P, F91S, L104T,











G111R, S112I











P18T, S52A, V57A, Q60R,
1732
187338
4.29
10579
0.28
908
1.11
3791
0.08


Q62K, S65C, L79P, F91T,











N100Y, T107M



















V11A, P18F, N35D, A47E,
1733
Little to no protein produced

















Q62K, L79P, F91S, G99D,











T107M, 5114N











V11A, P18T, N355, L79P,
1734
218660
5.00
273825
7.20
1269
1.56
69871
1.44


S87T, F91S











V9D, V11M, Q12L, P18S,
1735
8693
0.20
790
0.02
852
1.04
1991
0.04


E37V, M55I, Q60R, K70Q,











L79P, F91S, L104M,











T107M











T15S, P18S, Y30H, Q32L,
1736
16213
0.37
2092
0.06
1056
1.29
6994
0.14


Q62R, L79P, F91S, T107M











CD155-ECD-Fc
47
43704
1.00
38032
1.00
816
1.00
48638
1.00



(ECD)










CD112-IgV
795
1289

824

17819

1172
0.02
















TABLE 14A







Variant CD112 selected against cognate binding partners. Molecule


sequences, binding data, and costimulatory bioactivity data.















TIGIT
CD112R

Mock
Anti-CD3




tfxn
tfxn
CD226
Expi293
IFN-gamma




MFI
MFI
MFI
MFI
(pg/mL)



SEQ
(TIGIT
(CD112R
(CD226
(Mock
(Anti-CD3



ID
MFI
MFI
MFI
MFI
IFN-gamma



NO
parental
parental
parental
parental
parental


CD112 mutation(s)
(IgV)
ratio)
ratio)
ratio)
ratio)
ratio)
















WT CD112
795
210829
1452
265392
1112
676.6




(1.00)
(1.00)
(1.00)
(1.00)
(1.00)


Y33H, A112V, G117D
796
12948
1552
1368
1241
164.8




(0.06)
(1.07)
(0.01)
(1.12)
(0.24)


V19A, Y33H, S64G, S80G,
797
48356
1709
2831
1098



G98S, N106Y, A112V

(0.23)
(1.18)
(0.01)
(0.99)



L32P, A112V
798
191432
1557
11095
1259
390.4




(0.91)
(1.07)
(0.04)
(1.13)
(0.58)


A95V, A112I
799
238418
1706
51944
1215
282.5




(1.13)
(1.17)
(0.20)
(1.09)
(0.42)


P28S, A112V
800
251116
1985
153382
1189
503.4




(1.19)
(1.37)
(0.58)
(1.07)
(0.74)


P27A, T38N, V101A,
801
255803
2138
222822
1399
240.7


A112V

(1.21)
(1.47)
(0.84)
(1.26)
(0.36)


S118F
802
11356
5857
6938
1270
271.7




(0.05)
(4.03)
(0.03)
(1.14)
(0.40)


R12W, H48Y, F54S, S118F
803
10940
3474
5161
1069





(0.05)
(2.39)
(0.02)
(0.96)



R12W, Q79R, S118F
804
2339
7370
1880
1338
447.4




(0.01)
(5.08)
(0.01)
(1.20)
(0.66)


T113S, S118Y
805
6212
6823
1554
1214
225.1




(0.03)
(4.70)
(0.01)
(1.09)
(0.33)


S118Y
806
2921
6535
2003
1463
190.4




(0.01)
(4.50)
(0.01)
(1.32)
(0.28)


N106I, S118Y
807
2750
7729
1815
1222
265.8




(0.01)
(5.32)
(0.01)
(1.10)
(0.39)


N106I, S118F
808
1841
9944
1529
1308
437.9




(0.01)
(6.85)
(0.01)
(1.18)
(0.65)


A95T, L96P, S118Y
809
2352
4493
1412
1329
292.4




(0.01)
(3.09)
(0.01)
(1.19)
(0.43)


Y33H, P67S, N106Y,
810
225015
3259
204434
1296
618.8


A112V

(1.07)
(2.24)
(0.77)
(1.17)
(0.91)


N106Y, A112V
811
6036
1974
15334
1108
409.9




(0.03)
(1.36)
(0.06)
(1.00)
(0.61)


T18S, Y33H, A112V
812
252647
1347
183181
1412
601.8




(1.20)
(0.93)
(0.69)
(1.27)
(0.89)


P9S, Y33H, N47S, A112V
813
240467
1418
203608
1361
449.1




(1.14)
(0.98)
(0.77)
(1.22)
(0.66)


P42S, P67H, A112V
814
204484
1610
188647
1174
530.6




(0.97)
(1.11)
(0.71)
(1.06)
(0.78)


P27L, L32P, P42S, A112V
815
219883
1963
84319
1900
251.6




(1.04)
(1.35)
(0.32)
(1.71)
(0.37)


G98D, A112V
816
4879
2369
6100
1729
387.0




(0.02)
(1.63)
(0.02)
(1.55)
(0.57)


Y33H, S35P, N106Y,
817
250724
1715
94373
1495
516.2


A112V

(1.19)
(1.18)
(0.36)
(1.34)
(0.76)


L32P, P42S, T100A,
818
242675
1742
202567
1748
435.3


A112V

(1.15)
(1.20)
(0.76)
(1.57)
(0.64)


P27S, P45S, N106I, A112V
819
223557
1799
84836
1574
277.5




(1.06)
(1.24)
(0.32)
(1.42)
(0.41)


Y33H, N47K, A112V
820
251339
1525
199601
1325
483.2




(1.19)
(1.05)
(0.75)
(1.19)
(0.71)


Y33H, N106Y, A112V
821
297169
1782
258315
1440
485.4




(1.41)
(1.23)
(0.97)
(1.30)
(0.72)


K78R, D84G, A112V,
822
236662
1638
24850
1345
142.5


F114S

(1.12)
(1.13)
(0.09)
(1.21)
(0.21)


F54L, A112V
823
14483
1617
2371
1353
352.8




(0.07)
(1.11)
(0.01)
(1.22)
(0.52)


Y33H, A112V
824
98954
1216
1726
1298





(0.47)
(0.84)
(0.01)
(1.17)



A95V, A112V
825
168521
2021
200789
1459
412.9




(0.80)
(1.39)
(0.76)
(1.31)
(0.61)


R12W, A112V
826
135635
1582
23378
1412
165.8




(0.64)
(1.09)
(0.09)
(1.27)
(0.24)


A112V
832
213576
1986
151900
1409
211.4




(1.01)
(1.37)
(0.57)
(1.27)
(0.31)


Y33H, A112V
824
250667
1628
230578
1216
612.7




(1.19)
(1.12)
(0.87)
(1.09)
(0.91)


R12W, P27S, A112V
827
3653
1308
9105
1051





(0.02)
(0.90)
(0.03)
(0.94)



Y33H, V51M, A112V
828
218698
1384
195450
1170
709.4




(1.04)
(0.95)
(0.74)
(1.05)
(1.05)


Y33H, A112V, S118T
829
219384
1566
192645
1313
396.3




(1.04)
(1.08)
(0.73)
(1.18)
(0.59)


Y33H, V101A, A112V,
830
5605
1582
5079
1197



P115S

(0.03)
(1.09)
(0.02)
(1.08)



H24R, T38N, D43G,
831
227095
1537
229311
1336
858.6


A112V

(1.08)
(1.06)
(0.86)
(1.20)
(1.27)


A112V
832
4056
1356
10365
986





(0.02)
(0.93)
(0.04)
(0.89)



P27A, A112V
833
193537
1531
230708
3084
355.1




(0.92)
(1.05)
(0.87)
(2.77)
(0.52)


A112V, S118T
834
233173
1659
121817
845
533.3




(1.11)
(1.14)
(0.46)
(0.76)
(0.79)


R12W, A112V, M122I
835
235935
1463
217748
1350
528.0




(1.12)
(1.01)
(0.82)
(1.21)
(0.78)


Q83K, N106Y, A112V
836
205948
2042
234958
1551
481.4




(0.98)
(1.41)
(0.89)
(1.39)
(0.71)


R12W, P27S, A112V,
837
11985
2667
12756
1257
334.4


S118T

(0.06)
(1.84)
(0.05)
(1.13)
(0.49)


P28S, Y33H, A112V
838
4711
1412
3968
955





(0.02)
(0.97)
(0.01)
(0.86)



P27S, Q90R, A112V
839
3295
1338
6755
1048





(0.02)
(0.92)
(0.03)
(0.94)



L15V, P27A, A112V,
840
209888
1489
84224
1251
512.3


S118T

(1.00)
(1.03)
(0.32)
(1.13)
0.76)









Y33H, N106Y, T108I,
841
Not tested













A112V















Y33H, P56L, V75M,
842
Not tested













V101M, A112V






















TABLE 14B







Additional CD112 Variants and Binding Data.














TIGIT
CD226
CD112R
CD96

















SEQ

Fold
MFI
Fold
MFI
Fold
MFI
Fold



ID
MFI
Increase
at
Increase
at
Increase
at
Increase


CD112
NO
100
to WT
100
to WT
100
to WT
100
to WT


Mutation(s)
(IgV)
nM
IgV
nM
IgV
nM
IgV
nM
IgV



















S118F
802
1763
0.02
1645
0.08
2974
0.61
1659
0.19


N47K, Q79R,
925
1738
0.02
1689
0.09
2637
0.54
1647
0.19


S118F











Q40R, P60T,
926
4980
0.06
1608
0.08
2399
0.50
2724
0.32


A112V, S118T











F114Y, S118F
927
110506
1.34
7325
0.37
1502
0.31
1553
0.18


N106I, S118Y
807
1981
0.02
1700
0.09
2394
0.49
1582
0.19


S118Y
806
101296
1.23
9990
0.50
1429
0.30
1551
0.18


Y33H, K78R,
928
2276
0.03
2115
0.11
3429
0.71
2082
0.24


S118Y











N106I, S118F
808
1875
0.02
1675
0.08
2365
0.49
1662
0.19


R12W, A46T,
929
3357
0.04
1808
0.09
1664
0.34
4057
0.48


K66M, Q79R,











N106I, T113A,











S118F











Y33H, A112V,
930
3376
0.04
2886
0.15
3574
0.74
3685
0.43


S118F











R12W, Y33H,
931
100624
1.22
24513
1.24
1490
0.31
2060
0.24


N106I, S118F











L15V, Q90R,
932
5791
0.07
4169
0.21
2752
0.57
4458
0.52


S118F











N47K, D84G,
933
3334
0.04
2819
0.14
2528
0.52
3498
0.41


N106I, S118Y











L32P, S118F
934
3881
0.05
2506
0.13
2659
0.55
2518
0.29









Y33H, Q79R,
935
Low to no protein produced
















A112V, S118Y











T18A, N106I,
936
84035
1.02
10208
0.52
1585
0.33
1590
0.19


S118T


















L15V, Y33H,
937
Low to no protein produced
















N106Y, A112V,











S118F











V37M, S118F
938
96986
1.18
2523
0.13
1985
0.41
1849
0.22


N47K, A112V,
939
1980
0.02
1859
0.09
2733
0.56
1825
0.21


S118Y











A46T, A112V
940
4224
0.05
4685
0.24
3288
0.68
4273
0.50


P28S, Y33H,
941
6094
0.07
2181
0.11
1891
0.39
3021
0.35


N106I, S118Y











P30S, Y33H,
942
2247
0.03
2044
0.10
1796
0.37
2658
0.31


N47K, V75M,











Q79R, N106I,











S118Y











V19A, N47K,
943
2504
0.03
2395
0.12
2174
0.45
2852
0.33


N106Y, K116E,











S118Y











Q79R, T85A,
944
2192
0.03
1741
0.09
2367
0.49
1620
0.19


A112V, S118Y











Y33H, A112V
824
20646
0.25
1465
0.07
1794
0.37
2589
0.30
















TABLE 14B







Additional CD112 Variants and Binding Data.














TIGIT
CD226
CD112R
CD96

















SEQ

Fold

Fold

Fold

Fold



ID
MFI at
Increase
MFI at
Increase
MFI at
Increase
MFI at
Increase


CD112
NO
100
to WT
100
to WT
100
to WT
100
to WT


Mutation(s)
(IgV)
nM
IgV
nM
IgV
nM
IgV
nM
IgV



















V101M, N106I,
945
55274
0.67
6625
0.33
1357
0.28
1494
0.17


S118Y











Y33H, Q79R,
946
6095
0.07
1760
0.09
2393
0.49
3033
0.36


N106I, A112V,











S118T











Q79R, A112V
947
1571
0.02
1490
0.08
2284
0.47
1326
0.16


Y33H, A46T,
948
90813
1.10
15626
0.79
1298
0.27
3571
0.42


Q79R, N106I,











S118F











A112V, G121S
949
95674
1.16
19992
1.01
1252
0.26
4005
0.47


Y33H, Q79R,
950
36246
0.44
2118
0.11
1970
0.41
3250
0.38


N106I, S118Y











Y33H, N106I,
951
47352
0.57
4217
0.21
2641
0.55
1488
0.17


A112V











Y33H, A46T,
952
14413
0.17
1596
0.08
2335
0.48
1441
0.17


V101M,











A112V, S118T











L32P, L99M,
953
3056
0.04
1791
0.09
2210
0.46
2000
0.23


N106I, S118F











L32P, T108A,
954
104685
1.27
4531
0.23
2308
0.48
1518
0.18


S118F











A112V
832
4937
0.06
1903
0.10
1646
0.34
3011
0.35


R12W, Q79R,
955
55539
0.67
6918
0.35
1386
0.29
1740
0.20


A112V











Y33H, N106Y,
956
2786
0.03
2517
0.13
1787
0.37
2023
0.24


E110G, A112V











Y33H, N106I,
957
1967
0.02
1579
0.08
2601
0.54
1517
0.18


S118Y











Q79R, S118F
958
82055
1.00
7582
0.38
1298
0.27
1970
0.23


Y33H, Q79R,
959
21940
0.27
1632
0.08
1141
0.24
18423
2.16


G98D, V101M,











A112V











N47K, T81S,
960
6889
0.08
1311
0.07
1303
0.27
1145
0.13


V101M,











A112V, S118F











G82S, S118Y
961
4267
0.05
1938
0.10
2140
0.44
2812
0.33


Y33H, A112V,
962
14450
0.18
1532
0.08
2353
0.49
3004
0.35


S118Y











Y33H, N47K,
963
70440
0.85
3557
0.18
1447
0.30
1679
0.20


Q79R, N106Y,











A112V











Y33H, S118T
964
113896
1.38
17724
0.89
1252
0.26
5001
0.59


R12W, Y33H,
965
3376
0.04
2727
0.14
2047
0.42
2339
0.27


Q79R, V101M,











A112V











S118F
802
2685
0.03
1864
0.09
2520
0.52
1566
0.18


Wildtype
795
82414
1.00
19803
1.00
4842
1.00
8541
1.00


CD112-IgV Fc











CD112 ECD-Fc
48
29157
0.35
8755
0.44
1107
0.23
1103
0.13



(ECD)










Anti-hFc PE

1383
0.02
1461
0.07
1358
0.28
1468
0.17
















TABLE 14C







Additional CD112 Variants and Binding Data.














TIGIT
CD226
CD112R
CD96

















SEQ

Fold
MFI
Fold
MFI
Fold
MFI
Fold



ID
MFI
Increase
at
Increase
at
Increase
at
Increase


CD112
NO
20
to WT
20
to WT
20
to WT
20
to WT


Mutation(s)
(IgV)
nM
IgV
nM
IgV
nM
IgV
nM
IgV



















N106I, S118Y
807
1288
0.04
1334
0.12
6920
4.16
1102
0.44


Y33H, Q83K,
1503
115690
3.31
10046
0.93
1128
0.68
2053
0.82


A112V, S118T











R12W, Q79R,
804
1436
0.04
1296
0.12
6546
3.93
1046
0.42


S118F


















V29M, Y33H,
1504
Not tested
















N106I, S118F











Y33H, A46T,
1505
111256
3.18
14974
1.39
1148
0.69
3333
1.34


A112V











Y33H, Q79R,
1506
1483
0.04
1326
0.12
7425
4.46
1138
0.46


S118F











Y33H, N47K,
1507
1338
0.04
1159
0.11
1516
0.91
1140
0.46


F74L, S118F











R12W, V101M,
1508
1378
0.04
1249
0.12
5980
3.59
1182
0.47


N106I, S118Y











A46T, V101A,
1509
1359
0.04
1199
0.11
6729
4.04
1173
0.47


N106I, S118Y











Y33H, N106Y,
821
113580
3.25
17771
1.65
1207
0.72
2476
0.99


A112V


















N106Y, A112V,
1510
Not tested
















S118T


















S76P, T81I,
1511
Not tested
















V101M,











N106Y, A112V,











S118F











N106Y, A112V
811
29015
0.83
2760
0.26
1159
0.70
1639
0.66


P9R, L21V,
5112
1920
0.05
1218
0.11
1107
0.66
1074
0.43


P22L, I34M,











S69F, F74L,











A87V, A112V,











L125A











Y33H, V101M,
1513
126266
3.61
24408
2.27
1150
0.69
4535
1.82


A112V











N106I, S118F
808
1776
0.05
1385
0.13
9058
5.44
1370
0.55


V29A, L32P,
1514
1265
0.04
1148
0.11
5057
3.04
1194
0.48


S118F











A112V
832
69673
1.99
6387
0.59
1140
0.68
1214
0.49


Y33H, V101M,
1513
133815
3.83
24992
2.32
1184
0.71
6338
2.54


A112V











P285, Y33H,
941
2745
0.08
1689
0.16
6625
3.98
1978
0.79


N106I, S118Y











Y33H, V101M,
1515
118654
3.40
21828
2.03
1253
0.75
3871
1.55


N106I, A112V











R12W, Y33H,
1516
171390
4.91
5077
0.47
1124
0.68
2636
1.06


N47K, Q79R,











S118Y











A112V, S118T
834
103203
2.95
15076
1.40
1155
0.69
1426
0.57


Y33H, A46T,
1517
141859
4.06
29436
2.74
1184
0.71
5760
2.31


A112V, S118T











Y33H, A112V,
1518
5161
0.15
1734
0.16
1184
0.71
1249
0.50


F114L, S118I











A112V
832
78902
2.26
6224
0.58
1114
0.67
1181
0.47


Y33H, T38A,
1519
111293
3.19
25702
2.39
1192
0.72
99015
39.69


A46T, V101M,











A112V











Q79R, A112V
947
96674
2.77
7264
0.67
1130
0.68
1216
0.49


Y33H, N106I,
957
5720
0.16
1453
0.14
6543
3.93
1248
0.50


S118Y











P285, Y33H,
1520
22393
0.64
1378
0.13
1550
0.93
19174
7.68


S69P, N106I,











A112V, S118Y











Y33H, P42L,
1521
214116
6.13
13878
1.29
1315
0.79
4753
1.91


N47K, V101M,











A112V











Y33H, N47K,
1522
6719
0.19
1319
0.12
1305
0.78
1278
0.51


F745, Q83K,











N1061, F111L,











A112V, 5118T











Y33H, A112V,
1523
184794
5.29
10204
0.95
1269
0.76
4321
1.73


S118T, V119A











Y33H, N106I,
1524
6872
0.20
1591
0.15
2308
1.39
2796
1.12


A112V, S118F











Y33H, K66M,
1525
1724
0.05
1259
0.12
6782
4.07
1197
0.48


S118F, W124L











S118F
802
1325
0.04
1213
0.11
7029
4.22
1135
0.46


N1061, A112V
811
111342
3.19
4241
0.39
1546
0.93
1178
0.47


Y33H, A112V
824
177926
5.09
13761
1.28
1152
0.69
3117
1.25


WT CD112 IgV
795
34932
1.00
10762
1.00
1665
1.00
2495
1.00


WT CD112-Fc
48
28277
0.81
8023
0.75
1253
0.75
1064
0.43


ECD
(ECD)










Anti-huFc PE

1138
0.03
1006
0.09
1010
0.61
1062
0.43
















TABLE 15A







Selected PD-L1 variants and binding data.











Binding to Jurkat/PD-1 Cells











SEQ

Fold increase



ID
MFI
over wildtype



NO
at
PD-L1


PD-L1 Mutation(s)
(IgV)
50 nM
IgV-Fc













K28N, M41V, N45T, H51N, K57E
1389
12585
2.4


120L, I36T, N45D, I47T
1390
3119
0.6


120L, M41K, K44E
1391
9206
1.8


P6S, N4ST, N78I, I83T
1392
419
0.1


N78I
1393
2249
0.4









M41K, N78I
1394
Little or no protein produced


N17D, N45T, V50A, D72G
1400
Little or no protein produced


I20L, F49S
1401
Little or no protein produced










N45T, VS0A
1402
23887
4.6


I20L, N45T, N78I
1403
29104
5.6


N45T, N78I
1395
24865
4.7


I20L, N4ST
1396
24279
4.6


I20L, N45T, VS0A
1404
34158
6.5


N45T
1397
6687
1.3


M41K
1398
5079
1.0









M41V, N45T
1405
Little or no protein produced


M41K, N45T
1406
Little or no protein produced










A33D, S75P, D85E
1407
685
0.1


M18I, M41K, D43G, H51R, N781
1408
20731
4.0


V11E, 120L, I36T, N45D, H60R, S75P
1409
3313
0.6









A33D, V50A
1410
Little or no protein produced


S16G, A33D, K71E, S75P
1411
Little or no protein produced










E27G, N4ST, M97I
1412
881
0.2


E27G, N45T, K57R
1413
5022
1.0


A33D, E53V
1414
650
0.1


D43G, N45D, V58A
1415
63960
12.2


E40G, D43V, N45T, V50A
1416
809
0.2


Y14S, K28E, N45T
1417
16232
3.1


A33D, N78S
1418
1725
0.3


A33D, N781
1419
8482
1.6


A33D, N45T
1420
17220
3.3









A33D,N45T, N78I
1421
Little or no protein produced










E27G, N45T, V50A
1422
25267
4.8


N45T, V50A, N78S
1423
28572
5.4


N451, V50A
1402
18717
3.6


I20L, N45T, V110M
1424
464
0.1


I20L, I36T, N45T, V50A
1425
7658
1.5


N45T, L74P, S75P
1426
5251
1.0


N45T, S75P
1427
12200
2.3


S75P, K106R
1428
388
0.1


S75P
1429
1230
0.2


A33D, S75P
1430
306
0.1


A33D, S75P, D104G
1431
251
0.0


A33D, S75P
1430
1786
0.3


I20L, E27G, N45T, V50A
1433
29843
5.7


I20L, E27G, D43G, N45D, V58A, N78I
1434
69486
13.3


I20L, D43G, N45D, V58A, N78I
1435
72738
13.9


I20L, A33D, D43G, N45D, V58A, N78I
1436
80205
15.3


I20L, D43G, N45D, N78I
1437
67018
12.8


E27G, N45T, V50A, N78I
1438
30677
5.9


N45T, V50A, N78I
1439
32165
6.1


V11A, I20L, E27G, D43G, N45D, H51Y,
1440
73727
14.1


S99G





I20L, E27G, D43G, N45T, V50A
1441
36739
7.0


I20L, K28E, D43G, N45D, V58A, Q89R,
1442
80549
15.4


I20L, I36T, N45D
1443
16870
3.2


I20L, K28E, D43G, N45D, E53G, V58A,
1444
139
0.0


N78I





A33D, D43G, N45D, V58A, S75P
1445
58484
11.2


K23R, D43G, N45D
1446
67559
12.9


I20L, D43G, N45D, V58A, N78I, D90G,
1447
259
0.0


G101D





D43G, N45D, L56Q, V58A, G101G-
1448
88277
16.8


ins(G101GG)





I20L, K23E, D43G, N45D, V58A, N78I
1449
89608
17.1


I20L, K23E, D43G, N45D, V50A, N78I
1450
88829
16.9


T19I, E27G, N45I, V50A, N78I, M97K
1451
25496
4.9


120L, M41K, D43G, N45D
1452
599
0.1


K23R, N45T, N78I
1453
84980
16.2


Full length PD-L1 Fc

18465
3.5


Wild type PD-L1 IgV
1454
5243
1.0


Anti-PD-1 monoclonal antibody (niVolumab)

79787
15.2


Human IgG

198
0.0
















TABLE 15B







Flow Binding to Cells Expressing PD-1 or CD80












PD-1
CD80















Fold

Fold



SEQ

Change

Change



ID
MFI
Compared
MFI
Compared



NO
at
to WT
at
to WT


PD-L1 Mutation(s)
(ECD)
20 nM
PD-L1
20 nM
PD-L1















K57R, S99G
1813
2953
0.9
16253
121.3


K57R, S99G, F189L
1814
1930
0.6
12906
96.3


M18V, M97L, F193S, R195G, E200K,
1815
69
0.0
241
1.8


H202Q







I36S, M41K, M97L, K144Q, R195G,
1816
3498
1.1
68715
512.8


E200K, H202Q, L206F














C22R, Q65L, L124S, K144Q, R195G,
1817
Little or no protein produced












E200N, H202Q, T221L







M18V, I98L, L124S, P198T, L206F
1818
2187
0.7
143
1.1









S99G, N117S, I148V, K171R, R180S
1819
Little or no protein produced












I36T, M97L, A103V, Q155H
1820
120
0.0
128
1.0


K28I, S99G
1821
830
0.3
693
5.2


R195S
1822
3191
1.0
138
1.0


A79T, S99G, T185A, R195G, E200K,
1823
1963
0.6
643
4.8


H202Q, L206F







K57R, S99G, L124S, K144Q
1824
2081
0.7
14106
105.3


K57R, S99G, R195G
1825
2479
0.8
10955
81.8


D55V, M97L, S99G
1826
11907
3.8
71242
531.7


E27G, I36T, D55N, M97L, K111E
1827
1904
0.6
88724
662.1


E54G, M97L, S99G
1828
8414
2.7
51905
387.4


G15A, I36T, M97L, K111E, H202Q
1829
112
0.0
13530
101.0


G15A, I36T, V129D
1830
114
0.0
136
1.0


G15A, I36T, V129D, R195G
1831
125
0.0
134
1.0


G15A, V129D
1832
2075
0.7
128
1.0


I36S, M97L
1833
3459
1.1
44551
332.5


I36T, D55N, M97L, K111E, A204T
1834
265
0.1
62697
467.9


I36T, D55N, M97L, K111E, V129A,
1835
393
0.1
72641
542.1


F173L







I36T, D55S, M97L, K111E, I148V,
1836
94
0.0
30704
229.1


R180S







I36T, G52R, M97L, V112A, K144E,
1837
81
0.0
149
1.1


V175A, P198T







I36T, I46V, D55G, M97L, K106E,
1838
69
0.0
190
1.4


K144E, T185A, R195G







I36T, I83T, M97L, K144E, P198T
1839
62
0.0
6216
46.4









I36T, M97L, K111E
1840
Little or no protein produced












I36T, M97L, K144E, P198T
1841
197
0.1
40989
305.9


I36T, M97L, Q155H, F193S, N201Y
1842
69
0.0
1251
9.3


I36T, M97L, V129D
1843
523
0.2
50905
379.9


L35P, I36S, M97L, K111E
1844
190
0.1
155
1.2


M181, I36T, E53G, M97L, K144E,
1845
104
0.0
47358
353.4


E199G, V207A







M18T, I36T, D55N, M97L, K111E
1846
138
0.0
71440
533.1


M18V, M97L, T176N, R195G
1847
1301
0.4
45300
338.1


M97L, S99G
1848
12906
4.1
81630
609.2


N17D, M97L, S99G
1849
10079
3.2
73249
546.6


S99G, T185A, R195G, P198T
1850
2606
0.8
22062
164.6


V129D, H202Q
1851
2001
0.6
219
1.6


V129D, P198T
1852
3245
1.0
152
1.1


V129D, T150A
1853
1941
0.6
142
1.1


V93E, V129D
1854
1221
0.4
150
1.1


Y10F, M18V, S99G, Q138R, T203A
1855
70
0.0
412
3.1


WT PD-L1 (IgV + IgC) Fc
1812
3121
1.0
134
1.0


CTLA4-Fc

59
N/A
199670
N/A


Anti-PD1 mAb

31482
N/A
134
N/A


Fc Control
1189
59
N/A
132
N/A
















TABLE 15C







Additional Affinity-Matured IgSF Domain-Containing Molecules









SEQ



ID



NO


PD-L1 Mutation(s)
(ECD)





N45D
1945


K160M, R195G
1946


N45D, K144E
1947


N45D, P198S
1948


N45D, P198T
1949


N45D, R195G
1950


N45D, R195S
1951


N45D, S131F
1952


N45D, V58D
1953


V129D, R195S
1954


I98T, F173Y, L196S
1955


N45D, E134G, L213P
1956


N45D, F173I, S177C
1957


N45D, I148V, R195G
1958


N45D, K111T, R195G
1959


N45D, N113Y, R195S
1960


N45D, N165Y, E170G
1961


N45D, Q89R, I98V
1962


N45D, S131F, P198S
1963


N45D, S75P, P198S
1964


N45D, V50A, R195T
1965


E27D, N45D, T183A, I188V
1966


F173Y, T183I, L196S, T203A
1967


K23N, N45D, S75P, N120S
1968


N45D, G102D, R194W,
1969


R195G



N45D, G52V, Q121L, P198S
1970


N45D, I148V, R195G, N201D
1971


N45D, K111T, T183A, I188V
1972


N45D, Q89R, F189S, P198S
1973


N45D, S99G, C137R, V207A
1974


N45D, T163I, K167R, R195G
1975


N45D, T183A, T192S, R194G
1976


N45D, V50A, I119T, K144E
1977


T19A, N45D, K144E, R195G
1978


V11E, N45D, T130A, P198T
1979


V26A, N45D, T163I, T185A
1980


K23N, N45D, L124S, K167T,
1981


R195G



K23N, N45D, Q73R, T163I
1982


K28E, N45D, W149R, S158G,
1983


P198T



K28R, N45D, K57E, I98V,
1984


R195S



K28R, N45D, V129D, T163N,
1985


R195T



M41K, D43G, N45D, R64S,
1986


R195G



M41K, D43G, N45D, R64S,
1987


S99G



N45D, R68L, F173L, D197G,
1988


P198S



N45D, V50A, I148V, R195G,
1989


N201D



M41K, D43G, K44E, N45D,
1990


R195G, N201D



N45D, V50A, L124S, K144E,
1991


L179P, R195G









Example 9
Generation of Stacked Molecules Containing Different Affinity-Modified Domains

This Example describes further immunomodulatory proteins that were generated as multi-domain stack constructs containing at least two different affinity modified IgV domains from identified variant PD-L2 polypeptides and identified variant CD155 polypeptides described above. Specifically, the exemplary variant PD-L2 IgV H15Q/T47A/K65R/S67L/Q82R/V89D (SEQ ID NO:328) and the exemplary variant CD155 IgV molecule P18S/S65W/S67A/L104Q/G111R (SEQ ID NO:1598) were linked together and fused to an Fc in various configurations. Stack constructs were obtained as geneblocks (Integrated DNA Technologies, Coralville, Iowa) that either encoded the entire chain or they were generated by obtaining geneblocks that encode PDL2-CD155 in its various configurations for subsequent Gibson assembly into Fc fusion vector using a Gibson assembly kit (New England Biolabs). Homodimeric and heterodimeric stacks were generated in various configurations as summarized in FIG. 5A and as follows.


Homodimeric stack constructs were generated containing identical Fc subunits in which the variant PD-L2 IgV and variant CD155 IgV were variously linked to the N- or C-terminus of a human IgG1 Fc region via a 2×GGGS (SEQ ID NO:264) or 3×GGGGS (SEQ ID NO: 263) peptide linker. In this study, the exemplary IgG1 Fc subunit is set forth in SEQ ID NO:1189 and contained the mutations L234A, L235E, G237A, E356D and M358L by EU numbering (corresponding to L19A, L20E, G22A, E141D and M143L with reference to wild-type human IgG1 Fc set forth in SEQ ID NO:211). Further, the Fc region contained replacement of the cysteine residues to a serine residue at position 5 (C5 S) compared to the wild-type or unmodified Fc set forth in SEQ ID NO: 211 (corresponding to C220S by EU numbering). In some examples, the exemplary IgG1 Fc set forth in SEQ ID NO: 1189 was used, which contained the above mutations and additionally lacked the C-terminal lysine corresponding to position 232 of the wild-type or unmodified Fc set forth in SEQ ID NO: 211 (corresponding to K447del by EU numbering). Other Fc regions also are suitable for generation of stack molecules. Exemplary generated stacks are set forth below.


The homodimeric variant IgV-stacked-Fc fusion molecules containing various configurations of variant IgV domains from PD-L2 (SEQ ID NO: 328) and CD155 (SEQ ID NO:1598) were expressed and purified substantially as described in Example 5.


The encoding nucleic acid molecule was designed to produce homodimeric stacks in various configurations of sequences in the order shown:









PD-L2/CD155 Stack 1 (SEQ ID NO: 1191): CD155





variant (SEQ ID NO: 1598) - 2xGGGS (SEQ ID NO:





264) -Fc (SEQ ID NO: 1189) - 3x GGGGS (SEQ ID NO:





263) - PD-L2 (SEQ ID NO: 328)





PD-L2/CD155 Stack 2 (SEQ ID NO: 1192): PD-L2 (SEQ





ID NO: 328) - 2xGGGS (SEQ ID NO: 264) -Fc (SEQ ID





NO: 1189) - 3x GGGGS (SEQ ID NO: 263) - CD155





variant (SEQ ID NO: 1598)





PD-L2/CD155 Stack 3 (SEQ ID NO: 1193): CD155





variant (SEQ ID NO: 1598) -3x GGGGS (SEQ ID NO:





263) - PD-L2 (SEQ ID NO: 328) - 2xGGGS (SEQ ID NO:





264) -Fc (SEQ ID NO: 1189)





PD-L2/CD155 Stack 4 (SEQ ID NO: 1194): PD-L2 (SEQ





ID NO: 328) - 3x GGGGS (SEQ ID NO: 263) - CD155





variant (SEQ ID NO: 1598) - 2xGGGS (SEQ ID NO:





264) -Fc (SEQ ID NO: 1189)





PD-L2/CD155 Stack 5 (SEQ ID NO: 1195): Fc (SEQ ID





NO: 1189) - 3x GGGGS (SEQ ID NO: 263) - CD155





variant (SEQ ID NO: 1598) - 3xGGGS (SEQ ID NO:





263) - PD-L2 (SEQ ID NO: 328)





PD-L2/CD155 Stack 6 (SEQ ID NO: 1196): Fc (SEQ ID





NO: 1189) - 3x GGGGS (SEQ ID NO: 263) - PD-L2 (SEQ





ID NO: 328) - 3xGGGS (SEQ ID NO: 263) - CD155





variant (SEQ ID NO: 1598)






Heterodimeric stacks were generated in two ways. The first way was by co-expression of the variant PD-L2 IgV and/or variant CD155 IgV fused to (1) a first “knob” Fc subunit (set forth in SEQ ID NO:1187 containing the mutations S354C and T366W by EU numbering, corresponding to S139C and T151W with reference to wild-type human IgG1 Fc set forth in SEQ ID NO:211); and (2) a second “hole” Fc subunit (set forth in SEQ ID NO:1188, containing the mutations Y349C, T366S, L368A and Y407V by EU numbering, corresponding to Y134C, T151S, L153A and Y192V with reference to wild-type human IgG1 Fc set forth in SEQ ID NO:211) for expression of a heterodimeric molecule by “knobs-into-hole” engineering. In addition, both the knob and hole Fc also contained mutations L19A, L20E, G22A to reduce effector function and contained replacement of the cysteine residue to a serine residue at position 5 (C5 S), each compared to the wild-type or unmodified Fc set forth in SEQ ID NO: 211 (corresponding to C220S, L234A, L235E and G237A by EU numbering, respectively). In a second way, PDL2 and/or CD155 were fused to both knob and hole Fc's to generate stacks where each chain consists of Fc with fused IgV domain(s). For constructs in which the Fc sequence was the N-terminal portion of the sequence, a stuffer sequence HMSSVSAQ (SEQ ID NO:1190) was added immediately preceding the Fc sequence.


The heterodimeric variant IgV-stacked-Fc fusion molecules containing various configurations of variant IgV domains from PD-L2 (SEQ ID NO: 328) and CD155 (SEQ ID NO:1598) were expressed and purified substantially as described in Example 5. For each stack, the encoding nucleic acid molecule of the knob and hole were designed to produce heterodimeric stacks in various configurations with sequences in the order shown:









PD-L2/CD155 Stack 7 containing (1) knob Fc fusion





(SEQ ID NO: 1197): CD155 variant (SEQ ID NO:





1598) - 2xGGGS (SEQ ID NO: 264) - knob Fc (SEQ ID





NO: 1187) - 3x GGGGS (SEQ ID NO: 263) - PD-L2 (SEQ





ID NO: 328) 


and





(2) hole Fc (SEQ ID NO: 1188 plus





N-terminal HMSSVSAQ set forth in SEQ ID NO: 1190)





PD-L2/CD155 Stack 8 containing (1) knob Fc fusion





(SEQ ID NO: 1198): PD-L2 (SEQ ID NO: 328) - 2xGGGS





(SEQ ID NO: 264) - knob Fc (SEQ ID NO: 1187) - 3x





GGGGS (SEQ ID NO: 263) - CD155 variant (SEQ ID NO:





1598)





and





(2) hole Fc (SEQ ID NO: 1188 plus N-terminal





HMSSVSAQ set forth in SEQ ID NO: 1190)





PD-L2/CD155 Stack 9 containing (1) knob Fc fusion





(SEQ ID NO: 1199): CD155 variant (SEQ ID NO:





1598) - 3x GGGGS (SEQ ID NO: 263) - CD155 variant





(SEQ ID NO: 1598) - 2xGGGS (SEQ ID NO: 264) - knob





Fc (SEQ ID NO: 1187) - 3x GGGGS (SEQ ID NO: 263) -





PD-L2 (SEQ ID NO: 328) - 3x GGGGS (SEQ ID NO:





263) - PD-L2 (SEQ ID NO: 328);





and





(2) hole Fc (SEQ ID NO: 1188 plus N-terminal





HMSSVSAQ set forth in SEQ ID NO: 1190)





PD-L2/CD155 Stack 10 containing (1) knob Fc fusion





(SEQ ID NO: 1200): PD-L2 (SEQ ID NO: 328) - 3x





GGGGS (SEQ ID NO: 263) - PD-L2 (SEQ ID NO: 328) -





2xGGGS (SEQ ID NO: 264) - knob Fc (SEQ ID NO:





1187) - 3x GGGGS (SEQ ID NO: 263) - CD155 variant





(SEQ ID NO: 1598) - 3x GGGGS (SEQ ID NO: 263) -





CD155 variant (SEQ ID NO: 1598);





and





(2) hole Fc (SEQ ID NO: 1188 plus N-terminal





HMSSVSAQ set forth in SEQ ID NO: 1190)





PD-L2/CD155 Stack 11 containing (1) knob fc fusion





(SEQ ID NO: 1201): CD155 variant (SEQ ID NO:





1598) - 3x GGGGS (SEQ ID NO: 263) - CD155 variant





(SEQ ID NO: 1598) - 2xGGGS (SEQ ID NO: 264) -knob





Fc (SEQ ID NO: 1187);





and





(2) hole Fc fusion (SEQ ID NO: 1202): PD-L2 (SEQ





ID NO: 328) - 3x GGGGS (SEQ ID NO: 263) - PD-L2





(SEQ ID NO: 328) - 2xGGGS (SEQ ID NO: 264) - hole





Fc (SEQ ID NO: 1188)





PD-L2/CD155 Stack 12 containing (1) knob fc fusion





(SEQ ID NO: 1203): knob Fc (SEQ ID NO: 1187 plus





N-terminal HMSSVSAQ set forth in SEQ ID NO:





1190) - 3x GGGGS (SEQ ID NO: 263) - CD155 variant





(SEQ ID NO: 1598) - 3x GGGGS (SEQ ID NO: 263)





CD155 variant (SEQ ID NO: 1598);





and





(2) hole Fc (SEQ ID NO: 1204): hole Fc (SEQ ID NO:





1188 plus N-terminal HMSSVSAQ set forth in SEQ ID





NO: 1190) - 3x GGGGS (SEQ ID NO: 263) - PD-L2 (SEQ





ID NO: 328) - 3x GGGGS (SEQ ID NO: 263) - PD-L2





(SEQ ID NO: 328)





PD-L2/CD155 Stack 13 containing (1) knob Fc fusion





(SEQ ID NO: 1199): CD155 variant (SEQ ID NO:





1598) - 3x GGGGS (SEQ ID NO: 263) - CD155 variant





(SEQ ID NO: 1598) - 2xGGGS (SEQ ID NO: 264) - knob





Fc (SEQ ID NO: 1187) - 3x GGGGS (SEQ ID NO: 263) -





PD-L2 (SEQ ID NO: 328) - 3x GGGGS (SEQ ID NO:





263) - PD-L2 (SEQ ID NO: 328);





and





(2) hole Fc (SEQ ID NO: 1204): hole Fc (SEQ ID NO:





1188 plus N-terminal HMSSVSAQ set forth in SEQ ID





NO: 1190) - 3x GGGGS (SEQ ID NO: 263) - PD-L2 (SEQ





ID NO: 328) - 3x GGGGS (SEQ ID NO: 263) - PD-L2





(SEQ ID NO: 328)





PD-L2/CD155 Stack 14 containing (1) knob Fc fusion





(SEQ ID NO: 1199): CD155 variant (SEQ ID NO:





1598) - 3x GGGGS (SEQ ID NO: 263) - CD155 variant





(SEQ ID NO: 1598) - 2xGGGS (SEQ ID NO: 264) - knob





Fc (SEQ ID NO: 1187) - 3x GGGGS (SEQ ID NO:





263) - PD-L2 (SEQ ID NO: 328) - 3x GGGGS (SEQ ID





NO: 263) - PD-L2 (SEQ ID NO: 328);





and





(2) hole Fc fusion (SEQ ID NO: 1202): PD-L2 (SEQ





ID NO: 328) - 3x GGGGS (SEQ ID NO: 263) - PD-L2





(SEQ ID NO: 328) - 2xGGGS (SEQ ID NO: 264) - hole





Fc (SEQ ID NO: 1188)





PD-L2/CD155 Stack 15 containing (1) knob Fc fusion





(SEQ ID NO: 1200): PD-L2 (SEQ ID NO: 328) - 3x





GGGGS (SEQ ID NO: 263) - PD-L2 (SEQ ID NO: 328) -





2xGGGS (SEQ ID NO: 264) - knob Fc (SEQ ID NO:





1187) - 3x GGGGS (SEQ ID NO: 263) - CD155 variant





(SEQ ID NO: 1598) - 3x GGGGS (SEQ ID NO: 263) -





CD155 variant (SEQ ID NO: 1598);





and





(2) hole Fc fusion (SEQ ID NO: 1202): PD-L2 (SEQ





ID NO: 328) - 3x GGGGS (SEQ ID NO: 263) - PD-L2





(SEQ ID NO: 328) 2xGGGS (SEQ ID NO: 264) - hole





Fc (SEQ ID NO: 1188)





PD-L2/CD155 Stack 16 containing (1) knob Fc fusion





(SEQ ID NO: 1200): PD-L2 (SEQ ID NO: 328) - 3x





GGGGS (SEQ ID NO: 263) - PD-L2 (SEQ ID NO: 328) -





2xGGGS (SEQ ID NO: 264) - knob Fc (SEQ ID NO:





1187) - 3x GGGGS (SEQ ID NO: 263) - CD155 variant





(SEQ ID NO: 1598) - 3x GGGGS (SEQ ID NO: 263) -





CD155 variant (SEQ ID NO: 1598);





and





(2) hole Fc (SEQ ID NO: 1204): hole Fc (SEQ ID NO:





1188 plus N-terminal HMSSVSAQ set forth in SEQ ID





NO: 1190) - 3x GGGGS (SEQ ID NO: 263) - PD-L2 (SEQ





ID NO: 328) - 3x GGGGS (SEQ ID NO: 263) - PD-L2





(SEQ ID NO: 328)






Example 10
Generation of Secreted Immunomodulatory Protein

To generate a PD-L2 secreted immunomodulatory protein (SIP), DNA encoding exemplary SIPs was obtained as gene blocks from Integrated DNA Technologies (Coralville, USA) and then cloned by Gibson assembly (New England Biolabs Gibson assembly kit) into a modified version of pRRL vector (Dull et al., (1998) J Virol, 72(11): 8463-8471) between restriction sites downstream of MND promoter to remove GFP. Exemplary SIP constructs were generated to encode a protein set forth in SEQ ID NO: 1254-1257, including the signal peptide. In this exemplary Example, the constructs were generated to additionally include a tag moiety. The gene blocks had the following structure in order: 39 base pair overlap with pRRL prior to first restriction site-first restriction site-GCCGCCACC (Kozak); complete ORF encoding PD-L2 IgV wildtype amino acid sequence set forth in SEQ ID NO:115 or variant PD-L2 IgV set forth in SEQ ID NO:316 (H15Q,V31M,S67L,Q82R,V89D), SEQ ID NO:328 (H15Q,T47A,K65R,S67L,Q82R,V89D) or SEQ ID NO: 342 (H15Q,T47A,S67L,R76G,Q82R,V89D), also including in all cases the PD-L2 signal peptide MIFLLLMLSLELQLHQIAA as set forth in SEQ ID NO: 1251; DNA encoding Avitag as set forth in SEQ ID NO:1252 (GLNDIFEAQKIEWHE); DNA encoding His tag as set forth in SEQ ID NO: 1253 (HHHHHH); TAA stop codon; second restriction site-41 base pair overlap with pRRL beyond second restriction site.


To prepare lentiviral vectors, 3×106 HEK293 cells were plated per 100 mm dish. On the next day, 4.5 μg of P-Mix (3 μg of PAX2 and 1.5 μg of pMD2G) was added to 6 μg of DNA encoding the SIPs constructs in a 5 mL polypropylene tube. Diluent buffer (10 mM HEPES/150 mM NaCl pH7.05/1 L TC grade H20) was added to the tube to bring up the total volume of 500 μL. To the diluent DNA (PEI:total DNA 4:1), 424, of PEI (1 μg/μL) was added and mixed by vortexing. The mixture was incubated at room temperature for 10 minutes and cells were prepared by aspirating medium from the dish gently without disturbing the adherent cells, then replaced with 6 mL of Opti-MEM(1×). DNA/PEI mixture was then added to the dish and incubated at 37° C. for 24 hours. After 24 hours, media was aspirated from the dishes and replaced with 10 mL of fresh DMEM media and then incubated at 37° C. Viral supernatant was collected after 48 hours using a syringe attached to a 0.45 μm filter PES to remove cells and debris from the culture (Thermo Scientific Nalgene Syringe Filter). A separate lentiviral vector stock also was prepared encoding an anti-CD19 CAR (containing an anti-CD19 scFv, a hinge and transmembrane domain derived from CD8 and a CD3zeta signaling domain) substantially as described. The exemplary anti-CD19 CAR used is set forth in SEQ ID NO: 2024 (encoded by the sequence in set forth in SEQ ID NO: 2025) containing the scFv set forth in SEQ ID NO:1211, the CD8-derived hinge and transmembrane domain set forth in SEQ ID NO: 266, and the CD3zeta set forth in SEQ ID NO:267


Pan T-cells were transduced with the viral vectors encoding the PD-L2 SIPs. T-cells were thawed and activated with anti-CD3/anti-CD28 beads (Dynal) at a 1:1 ratio. The T-cells (1×106 cells) were mixed with 1 mL total lentiviral vector supernatant containing equal volume (0.5 mL each) of the lentiviral vector supernatant encoding the indicated PD-L2 SIPs and a lentiviral vector supernatant encoding the anti-CD19 CAR. As a control, cells were transduced only with the lentiviral vector encoding the anti-CD19 CAR or were transduced with mock vector control. Transduction was performed in the presence of 10 μg/mL polybrene and 50 IU/mL IL-2. Cells were spun down at 2500 rpm for 60 min at 30° C. After 24 hours, 3 mL of Xvivo15 plus media and IL2 was added to each well. The cells were fed every two days with fresh media and cytokines.


Transduction also was carried out on HEK-293 cells, which were resuspended at 2×105 cells with 1 mL of the lentiviral supernatant encoding the indicated PD-L2 SIPs. To the cells, 3 mL of DMEM media was added and cells were fed every two days with fresh media.


To assess the amount of secreted SIP, a cell-based assay was performed to assess binding of the secretable variant PD-L2 to PD-1. Approximately, 100,000 PD-1+ Jurkat cells were plated per well in the presence of 504, of culture supernatant containing PD-L2 SIP obtained from transduced cells above and incubated at 4° C. for 30 minutes. To generate a standard curve, 50 μL of the respective variant PD-L2 protein was added to PD-1+ Jurkat cells at 10 μg/mL, 3 μg/mL, 1 μg/mL, 0.3 μg/mL, 0.1 μg/mL, and 0 μg/mL and also incubated at 4° C. for 30 minutes. Cells were washed and 50 μL of anti-his-APC were added (1:50) and this was incubated at 4° C. for 30 minutes. Surface bound PD-L2 protein was detected by flow cytometry and the concentration of SIP in the supernatant sample was determined by comparison to the standard curve. As shown in FIGS. 11A and 11B, SIP proteins were detected in the supernatant of transduced T cells and transduced HEK293 cell, but were not detected from supernatant samples from mock transduced or cells transduced without SIPs.


Example 11
Assessment of Proliferation and Bioactivity of Pan T Cells Transduced with PD-L2 SIP

Pan T-cells were transduced essentially as described in Example 10 with the viral vectors encoding the PD-L2 SIPs. T-cells were thawed and activated with anti-CD3/anti-CD28 beads (Dynal) at a 1:1 ratio. The T-cells (1×106 cells) were mixed with 1 mL total lentiviral vector supernatant containing equal volume (0.5 mL each) of the lentiviral vector supernatant encoding the indicated PD-L2 SIPs and a lentiviral vector supernatant encoding the anti-CD19 CAR. As a control, cells were transduced only with the lentiviral vector encoding the anti-CD19 CAR or were transduced with mock vector control. Transduction was performed in the presence of 10 μg/mL polybrene and 50 IU/mL IL-2. Cells were spun down at 2500 rpm for 60 min at 30° C. After 24 hours, 3 mL of Xvivo15 plus media and IL2 was added to each well. The cells were fed every two days with fresh media and cytokines.


At 14 days after activation, cells were re-stimulated with Nalm6 cells that had been transduced with a lenti-viral vector to provide expression of PDL1. Transduced T cells were labeled with Cell Trace Far Red and proliferation was measured by determining the fraction of the cells that showed dilution of the dye. Results for the proliferation studies for T cells transduced with exemplary tested variant PD-L2 SIP are shown in FIG. 12A.


Levels of IFN-gamma released into the supernatant were measured by ELISA on day 5 after re-stimulation. Results for the bioactivity studies for T cells transduced with exemplary tested variant PD-L2 SIP are shown in FIG. 12B. The T cells transduced with PD-L2 variant SIP are identified with reference to the amino acid substitutions in the IgV of PD-L2 with reference to positions corresponding to positions of the unmodified (wildtype) PD-L2 ECD sequence set forth in SEQ ID NO:31. As shown in FIGS. 12A and 12B, proliferation and improved activities to increase immunological activity was observed.


Example 12
Assessment of Binding to Cell-Expressed Counter Structures and Bioactivity of Affinity-Matured IgSF Domain-Containing Stack Molecules

This Example describes Fc-fusion binding studies to show specificity and affinity of exemplary PD-L2/CD155 stack immunomodulatory proteins generated in Example 9 for cognate binding partners. The exemplary PD-L2/CD155 stack immunomodulatory proteins generated in Example 9 also were assessed for Fc-fusion variant protein bioactivity characterization in a human primary T cell in vitro assay.


A. Binding to Cell-Expressed Counter Structure


Binding studies were carried out using Jurkat/IL-2 reporter cells (purchased from Promega Corp. USA) that were transduced to stably express human PD-1 (Jurkat/PD-1 cells), human TIGIT (Jurkat/TIGIT cells) or both PD-1 and TIGIT (Jurkat/PD-1/TIGIT cells). For staining by flow cytometry, 100,000 Jurkat/PD-1, Jurkat/TIGIT, Jurkat/PD-1/TIGIT cells or negative control (Jurkat only) were plated in 96-well round-bottom plates. Cells were spun down and resuspended in staining buffer (PBS (phosphate buffered saline), 1% BSA (bovine serum albumin), and 0.1% sodium azide) for 20 minutes to block non-specific binding. Afterwards, cells were centrifuged again and resuspended in 50 μL staining buffer containing 100 nM to 46 pM of each candidate Fc fusion protein. Primary staining was performed on ice for 90 minutes, before washing cells twice in 200 μL staining buffer. PE-conjugated anti-human Fc (Jackson ImmunoResearch, USA) was diluted 1:150 in 50 μL staining buffer and added to cells and incubated another 30 minutes on ice. Secondary antibody was washed out twice, cells were fixed in 4% formaldehyde/PBS, and samples were analyzed on Intellicyt flow cytometer (Intellicyt Corp., USA).


Mean Fluorescence Intensity (MFI) was calculated with FlowJo Version 10 software (FlowJo LLC, USA). Table 16 sets forth binding activity as measured by the Mean Fluorescence Intensity (MFI) value for binding of 6.25 nM of each stack Fc-fusion molecule to Jurkat/PD-1, Jurkat/TIGIT, and Jurkat/PD-1/TIGIT cells. As shown in Table 16, several stack proteins bind both PD-1 and TIGIT with high affinity.









TABLE 16







Binding of PD-L2/CD155 Stacks to Cell-Expressed Counter Structure













Binding to Jurkat





Transfectants




SEQ
MFI at 6.25 nM














ID


TIGIT +


Category
Description
NO
PD1
TIGIT
PD1















Homodimers
(CD155 IgV)—(G4S)2—Fc—(G4S)3 
1191
242
19948
5336



(PD-L2 IgV)







(PD-L2 IgV) (G4S)2 Fc (G4S)3 
1192
16344
9095
16458



(CD155 IgV)







(CD155 IgV) (G4S)3 (PD-L2 IgV) 
1193
91
22342
8135



(G4S)2 Fc







(PD-L2 IgV) (G4S)3 
1194
9218
14516
19256



(CD155 IgV) (G4S)2 Fc







Fc (G4S)3 (CD155 IgV) 
1195
108
5486
2905



(G4S)3 (PD-L2 IgV)







Fc (G4S)3 (PD-L2 IgV) 
1196
66
9974
5202



(G4S)3 (CD155 IgV)






Heterodimers
(CD155 IgV) (G4S)2 knob Fc—
1197 + 1188
107
2544
1512



(G4S)3 (PD-L2 IgV) and hole Fc







(PD-L2 IgV) (G4S)2 knob Fc 
1198 + 1188
1658
360
6762



(G4S)3 (CD155 IgV) and hole Fc







(CD155 IgV) (G4S)3 (CD155
1199 + 1188
289
8677
4371



IgV) (G4S)2 knob Fc (G4S)3 







(PD-L2 IgV) (G4S)3 (PD-L2 IgV)







and hole Fc







(PD-L2 IgV) (G4S)3 (PD-L2 IgV) 
1200 + 1188
1594
2554
5509



(G4S)2 knob Fc (G4S)3 







(CD155 IgV) (G4S)3 (CD155







IgV) and hole Fc







(CD155 IgV) (G4S)3 (CD155
1201 + 1202
1758
9642
9343



IgV) (G4S)2 knob Fc and (PD-L2







IgV) (G4S)3 (PD-L2 IgV) 







(G4S)2 hole Fc







(CD155 IgV) (G4S)3 (CD155
1199 + 1202
4821
7596
8081



IgV) (G4S)2 knob Fc (G4S)3 







(PD-L2 IgV) (G4S)3 (PD-L2 IgV)







and (PD-L2 IgV) (G4S)3 (PD-L2







IgV) (G4S)2 hole Fc







(CD155 IgV) (G4S)3 (CD155
1199 + 1204
515
8299
4228



IgV) (G4S)2 knob Fc (G4S)3 







(PD-L2 IgV) (G4S)3 (PD-L2 IgV)







and hole Fc (G4S)3 (PD-L2 IgV) 







(G4S)3 (PD-L2 IgV)







(PD-L2 IgV) (G4S)3 (PD-L2 IgV) 
1200 + 1202
10970
3339
9014



(G4S)2 knob Fc (G4S)3 







(CD155 IgV) (G4S)3 (CD155







IgV) and (PD-L2 IgV) (G4S)3 







(PD-L2 IgV) (G4S)2 hole Fc







(PD-L2 IgV) (G4S)3 (PD-L2 IgV) 
1200 + 1204
3785
1475
5989



(G4S)2 knob Fc (G4S)3 







(CD155 IgV) (G4S)3 (CD155







IgV) and hole Fc (G4S)3 (PD-L2







IgV) (G4S)3 (PD-L2 IgV)






Controls
PDL2-IgV
328
22448
73
20280



CD155-IgV
1598
133
22342
4893



Fc Control (homodimer)
1189
44
86
66



Fc Control (heterodimer)
1187 + 1188
42
48
48



Wild Type CD155 full ECD Fc
20 (ECD)
64
4547
249



Wild Type PD-L2 full ECD Fc
 4 (ECD)
392
46
314



Irrelevant Ig Control
hIgG
41
48
41









B. Assessment of Bioactivity of Affinity-Matured IgSF Domain-Containing Molecules Using Mixed Lymphocyte Reaction (MLR)


Soluble PD-L2/CD155 stack protein bioactivity was tested in a human Mixed Lymphocyte Reaction (MLR). Human primary dendritic cells (DC) were generated by culturing monocytes isolated from PBMC (BenTech Bio, USA) in vitro for 7 days with 50 ng/mL rIL-4 (R&D Systems, USA) and 80 ng/mL rGM-CSF (R&D Systems, USA) in Ex-Vivo 15 media (Lonza, Switzerland). To induce DC maturation, lipopolysaccharide (LPS) (InvivoGen Corp., USA) was added to the DC cultures on day 6 and cells were incubated for an additional 24 hours. Approximately 10,000 matured DC and 100,000 purified allogeneic CD3+ T cells (BenTech Bio, USA) were co-cultured with several concentrations of PD-L2/CD155 stack or control proteins in 96 well round-bottom plates in 200 μL final volume of Ex-Vivo 15 media. Irrelevant human IgG and homodimeric and heterodimeric empty Fc proteins were used as negative controls. As positive controls, PD-L2-Fc (full PD-L2 extracellular domain), wildtype CD155-Fc (full CD155 extracellular domain) were assessed. Variant PD-L2 IgV-Fc fusion proteins were tested at 20 nM. On day 5, IFN-gamma secretion in culture supernatants was analyzed using the Human IFN-gamma Duoset ELISA kit (R&D Systems, USA). Optical density was measured on a BioTek Cytation Multimode Microplate Reader (BioTek Corp., USA) and quantitated against titrated rIFN-gamma standard included in the IFN-gamma Duo-set kit (R&D Systems, USA).


Results for the bioactivity studies for exemplary tested PD-L2/CD155 stack proteins are summarized in Table 17, which sets forth the calculated levels of IFN-gamma in culture supernatants (pg/mL). The sequence identifier (SEQ ID NO) for each stack proteins is set forth in column 3. As shown in Table 17, culture supernatants incubated in the presence of exemplary PD-L2/CD155 stack proteins exhibited altered levels of IFNg production in the MLR assay.









TABLE 17







Bioactivity Data of PD-L2/CD155 Stacks













Mixed Lymphocyte





Reaction:





IFNg at 96 hours















Fold






Increase




SEQ

compared




ID
IFNg
to IgG


Category
Description
NO
[pg/mL]
Control





Homodimers
(CD155 IgV)  (G4S)2 Fc (G4S)3 
1191
3097.0
1.3



(PD-L2 IgV)






(PD-L2 IgV) (G4S)2 Fc (G4S)3 
1192
3700.3
1.6



(CD155 IgV)






(CD155 IgV) (G4S)3 (PD-L2 IgV) 
1193
3061.6
1.3



(G4S)2 Fc






(PD-L2 IgV) (G4S)3 (CD155 IgV) 
1194
2270.0
1.0



(G4S)2 Fc






Fc (G4S)3 (CD155 IgV) (G4S)3 
1195
2003.5
0.9



(PD-L2 IgV)






Fc (G4S)3 (PD-L2 IgV) (G4S)3 
1196
2951.0
1.3



(CD155 IgV)





Heterodimers
(CD155 IgV)—(G4S)2 knobFc 
1197 + 1188
2040.4
0.9



(G4S)3 (PD-L2 IgV) and hole Fc






(PD-L2 IgV) (G4S)2 knob Fc (G4S)3—
1198 + 1188
3768.6
1.6



(CD155 IgV) and hole Fc






(CD155 IgV)—(G4S)3 (CD155 IgV) 
1199 + 1188
3549.7
1.5



(G4S)2 knob Fc (G4S)3 (PD-L2 IgV) 






(G4S)3 (PD-L2 IgV) and hole Fc






(PD-L2 IgV) (G4S)3—(PD-L2 IgV) 
1200 + 1188
2568.6
1.1



(G4S)2 knob Fc (G4S)3 (CD155






IgV) (G4S)3 (CD155 IgV) and hole Fc






(CD155 IgV) (G4S)3 (CD155 IgV) 
1201 + 1202
2572.1
1.1



(G4S)2 knob Fc and (PD-L2 IgV) 






(G4S)3 (PD-L2 IgV) (G4S)2 hole Fc






(CD155 IgV)—(G4S)3 (CD155 IgV) 
1199 + 1202
3216.7
1.4



(G4S)2 knob Fc (G4S)3 (PD-L2 IgV)—






(G4S)3 (PD-L2 IgV) and (PD-L2 IgV)—






(G4S)3 (PD-L2 IgV) (G4S)2 hole Fc






(CD155 IgV)—(G4S)3 (CD155 IgV) 
1199 + 1204
2673.4
1.2



(G4S)2 knob Fc (G4S)3 (PD-L2 IgV)—






(G4S)3 (PD-L2 IgV) and hole Fc 






(G4S)3 (PD-L2 IgV) (G4S)3 (PD-L2






IgV)






(PD-L2 IgV) (G4S)3—(PD-L2 IgV) 
1200 + 1202
2361.6
1.0



(G4S)2 knob Fc (G4S)3 (CD155






IgV) (G4S)3 (CD155 IgV) and (PD-






L2 IgV) (G4S)3 (PD-L2 IgV) (G4S)2—






hole Fc






(PD-L2 IgV) (G4S)3—(PD-L2 IgV) 
1200 + 1204
3311.8
1.4



(G4S)2 knob Fc (G4S)3 (CD155






IgV) (G4S)3 (CD155 IgV) and hole Fc—






(G4S)3—(PD-L2 IgV)—(G4S)3—(PD—






L2 IgV)





Controls
PDL2-IgV
 328
2367.2
1.0



CD155-IgV
1598
2590.7
1.1



Fc Control (homodimer)
1189
2617.9
1.1



Fc Control (heterodimer)
1187 + 1188
2861.5
1.2



Wild Type CD155 full ECD Fc
20 (ECD)
2481.0
1.1



Wild Type PD-L2 full ECD Fc
 4 (ECD)
3298.5
1.4



Irrelevant Ig Control
hIgG
2297.6
1.0









The present invention is not intended to be limited in scope to the particular disclosed embodiments, which are provided, for example, to illustrate various aspects of the invention. Various modifications to the compositions and methods described will become apparent from the description and teachings herein. Such variations may be practiced without departing from the true scope and spirit of the disclosure and are intended to fall within the scope of the present disclosure.

Claims
  • 1. A variant PD-L2 polypeptide, comprising an IgV domain or both an IgV domain and an IgC domain, wherein the variant PD-L2 polypeptide comprises one or more amino acid substitutions in an unmodified PD-L2, with reference to numbering of SEQ ID NO:31; wherein the one or more amino acid substitutions are selected from the group consisting of H15Q, H15Q/K65R, H15Q/Q72H/V89D, H15Q/S67L/R76G, H15Q/T47A/Q82R, H15Q/Q82R/V89D, H15Q/S67L/I86T, I13V/H15Q/S67L/I86T, I13V/H15Q/E44D/V89D, H15Q/T47A/Q72H/R76G/I86T, H15Q/T47A/Q72H/R76G, I13V/H15Q/T47A/Q72H/R76G, H15Q/S39I/S67L/V89D, H15Q/N32D/S67L/V89D, H15Q/S67L/Q72H/R76G/V89D, I13V/H15Q/S39I/E44D/S67L, H15Q/V89D, H15Q/T47A, I13V/H15Q/Q82R, I13V/H15Q/V89D, I13V/H15Q/Q82R/V89D, H15Q/V31M/S67L/Q82R/V89D, I13V/H15Q/T47A/Q82R, I13V/H15Q/V31A/N45S/Q82R/V89D, H15Q/T47A/H69L/Q82R/V89D, I13V/H15Q/T47A/H69L/R76G/V89D, I12V/I13V/H15Q/T47A/Q82R/V89D, I13V/H15Q/R76G/D77N/Q82R/V89D, I13V/H15Q/T47A/R76G/V89D, I13V/H15Q/T47A/Q82R/V89D, I13V/H15Q/I36V/T47A/S67L/V89D, H15Q/T47A/K65R/S67L/Q82R/V89D, H15Q/L33P/T47A/S67L/P71S/V89D, I13V/H15Q/Q72H/R76G/I86T, H15Q/T47A/S67L/Q82R/V89D, F2L/H15Q/D46E/T47A/Q72H/R76G/Q82R/V89D, I13V/H15Q/L33F/T47A/Q82R/V89D, H15Q/N24S/T47A/Q72H/R76G/V89D, I13V/H15Q/E44V/T47A/Q82R/V89D, H15Q/N18D/T47A/Q72H/V73A/R76G/I86T/V89D, I13V/H15Q/T37A/E44D/S48C/S67L/Q82R/V89D, H150/L33H/S67L/R76G/Q82R/V89D, I13V/H15Q/T47A/Q72H/R76G/I86T, H15Q/S39I/E44D/Q72H/V75G/R76G/Q82R/V89D, H15Q/T47A/S67L/R76G/Q82R/V89D, and I13V/H15Q/T47A/S67L/Q72H/R76G/Q82R/V89D;wherein the unmodified PD-L2 comprises the sequence of amino acids set forth in SEQ ID NO:31, or a portion thereof comprising an IgV domain;wherein the variant PD-L2 polypeptide comprises a sequence of amino acids that exhibits at least 90% sequence identity to SEQ ID NO:31 or the portion of SEQ ID NO:31 comprising the IgV domain; andwherein the variant PD-L2 polypeptide specifically binds to the ectodomain of PD-1 with increased affinity compared to the binding of the unmodified PD-L2 to the ectodomain of PD-1.
  • 2. The variant PD-L2 polypeptide of claim 1 that is a soluble protein.
  • 3. An immunomodulatory protein comprising the variant PD-L2 polypeptide of claim 1, wherein the variant PD-L2 polypeptide is linked to a multimerization domain.
  • 4. The immunomodulatory protein of claim 3, wherein the multimerization domain is an Fc domain or a variant Fc domain with reduced effector function.
  • 5. The variant PD-L2 polypeptide of claim 1, wherein the variant PD-L2 polypeptide comprises a transmembrane domain.
  • 6. The variant PD-L2 polypeptide of claim 5, further comprising a cytoplasmic signaling domain.
  • 7. A pharmaceutical composition, comprising the variant PD-L2 polypeptide of claim 1.
  • 8. An article of manufacture or kit comprising the pharmaceutical composition of claim 7.
  • 9. A pharmaceutical composition, comprising the immunomodulatory protein of claim 4.
CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Stage of International Application No. PCT/US2018/022267 filed Mar. 13, 2018, which claims priority from U.S. provisional application No. 62/472,572 filed Mar. 16, 2017, entitled “PD-L2 Variant Immunomodulatory Proteins and Uses Thereof,” U.S. provisional application No. 62/475,156 filed Mar. 22, 2017, entitled “PD-L2 Variant Immunomodulatory Proteins and Uses Thereof,” and U.S. provisional application No. 62/537,928 filed Jul. 27, 2017, entitled “PD-L2 Variant Immunomodulatory Proteins and Uses Thereof,” the contents of each of which are incorporated by reference in their entirety.

PCT Information
Filing Document Filing Date Country Kind
PCT/US2018/022267 3/13/2018 WO
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Related Publications (1)
Number Date Country
20210130437 A1 May 2021 US
Provisional Applications (3)
Number Date Country
62537928 Jul 2017 US
62475156 Mar 2017 US
62472572 Mar 2017 US