Patent Application
20240352481
The contents of the electronic sequence listing (V029170033WO00-SEQ-CEW.xml; Size: 50,584 bytes; and Date of Creation: Jul. 29, 2022) is herein incorporated by reference in its entirety.
T-cells expressing chimeric antigen receptors (CARs) have exhibited efficacious treatment of hematological malignancies. Upon antigen binding, CARs initiate Ca2+-dependent signaling pathways, leading to an increased intracellular concentration of nuclear factor of activated T cells (NFAT), which stimulates downstream T cell effector functions (Hogan, Cell Calcium. (2017) 63:66-9; Chow, Molecular and Cellular Biology (1999) 19(3): 2300-7).
In some aspects, the present disclosure provides a nucleic acid construct comprising a nucleotide sequence encoding a reporter molecule operably linked to a minimal nuclear factor of activated T cells (NFAT)-responsive promoter. In some embodiments, the NFAT-responsive promoter comprises least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 NFAT binding site. In some embodiments, the NFAT-responsive promoter comprises a minimal IL-2 promoter comprising a TATA box. In some embodiments, the NFAT-responsive promoter comprises 6 NFAT binding site located 5′ to the TATA box. In some embodiments, at least one of the NFAT binding sites comprises the nucleotide sequence of SEQ ID NO: 1. In some embodiments, each of the NFAT binding sites comprises the nucleotide sequence of SEQ ID NO: 1.
In some embodiments, the minimal IL-2 promoter comprises the nucleotide sequence of SEQ ID NO: 2. In some embodiments, the minimal NFAT-responsive promoter comprises the nucleotide sequence of SEQ ID NO: 3.
In some embodiments, the nucleic acid construct further comprises a nucleotide sequence encoding a second reporter molecule operably linked to a constitutive promoter. In some embodiments, the constitutive promoter is an elongation factor 1 alpha (EF-1alpha) promoter comprising the nucleotide sequence of SEQ ID NO: 4.
In some aspects, the present disclosure provides a vector comprising any one of the nucleic acid constructs described herein. In some embodiments, the vector is a plasmid. In some embodiments, the vector is a viral vector. In some embodiments, the viral vector is a lentiviral vector, an adenoviral associated viral vector, or a retroviral vector.
In some aspects, the present disclosure provides a reporter cell line comprising any one of the nucleic acid constructs described herein or any one of the vectors described herein. In some embodiments, the reporter cell line is an immune cell line. In some embodiments, the reporter cell line has T-lymphocyte function. In some embodiments, the reporter cell line is susceptible to T-cell activation. In some embodiments, the T cell activation is by phorbol myristate acetate (PMA) and/or ionomycin. In some embodiments, the cell line further expresses a chimeric antigen receptor.
In some aspects, the present disclosure provides a method of measuring the ability of a candidate chimeric antigen receptor (CAR) to induce nuclear factor of activated T cells (NFAT)-signaling in a cell. In some aspects, the method comprises (i) expressing any one or more of the nucleic acid constructs or vectors described herein in a T-lymphocyte expressing a candidate CAR targeting an antigen; (ii) contacting the T-lymphocyte of (i) with an activating agent; (iii) measuring a level of activity of the minimal NFAT-responsive promoter in the T-lymphocyte; and (iv) comparing the level of activity of the minimal NFAT-responsive promoter to a level of activity of a reference promoter in the T-lymphocyte, wherein the level of activity of the minimal NFAT-responsive promoter compared to a level of activity of a reference promoter indicates the ability of the CAR to induce NFAT signaling in the cell. In some embodiments, the activating agent is a cell comprising the antigen. In some embodiments, the antigen is a tumor antigen or cancer antigen. In some embodiments, the antigen is a cell-surface lineage-specific antigen. In some embodiments, measuring the level of activity of the minimal NFAT-responsive promoter comprises measuring expression of the reporter molecule under control of the NFAT-responsive promoter. In some embodiments, measuring the level of activity of the reference promoter comprises measuring expression of a reporter molecule under control of a constitutive promoter.
The summary above is meant to illustrate, in a non-limiting manner, some of the embodiments, advantages, features, and uses of the technology disclosed herein. Other embodiments, advantages, features, and uses of the technology disclosed herein will be apparent from the Detailed Description, the Drawings, the Examples, and the Claims.
In order for the present invention to be more readily understood, certain terms are first defined below. Additional definitions for the following terms and other terms are set forth throughout the specification. The publications and other reference materials referenced herein to describe the background of the invention and to provide additional detail regarding its practice are hereby incorporated by reference.
The articles “a” and “an” are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. By way of example, “an element” means one element or more than one element.
Approximately or about: As used herein, the term “approximately” or “about,” as applied to one or more values of interest, refers to a value that is similar to a stated reference value. In certain embodiments, the term “approximately” or “about” refers to a range of values that fall within 25%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, or less in either direction (greater than or less than) of the stated reference value unless otherwise stated or otherwise evident from the context (except where such number would exceed 100% of a possible value).
Agent: As used herein, the term “agent” (or “biological agent” or “therapeutic agent”), refers to a molecule that may be expressed, released, secreted or delivered to a target by a modified cell (e.g., an immune cell comprising a chimeric antigen receptor) described herein. An agent includes, but is not limited to, a nucleic acid, an antibiotic, an anti-inflammatory agent, an antibody or fragments thereof, a chimeric antigen receptor, an antibody agent or fragments thereof, a growth factor, a cytokine, an enzyme, a protein (e.g., an RNAse inhibitor), a peptide, a fusion protein, a synthetic molecule, an organic molecule (e.g., a small molecule), a carbohydrate, a lipid, a hormone, a microsome, a derivative or a variation thereof, and any combinations thereof. An agent may bind any cell moiety, such as a receptor, an antigenic determinant, or other binding site present on a target or target cell. An agent may diffuse or be transported into a cell, where it may act intracellularly.
Antibody: As used herein, the term “antibody” refers to a polypeptide that includes canonical immunoglobulin sequence elements sufficient to confer specific binding to a particular target antigen. As is known in the art, intact antibodies as produced in nature are approximately 150 kD tetrameric agents comprising two identical heavy chain polypeptides (about 50 kD each) and two identical light chain polypeptides (about 25 kD each) that associate with each other into what is commonly referred to as a “Y-shaped” structure. Each heavy chain comprises at least four domains (each about 110 amino acids long)—an amino-terminal variable (VH) domain (located at the tips of the Y structure), followed by three constant domains: CH1, CH2, and the carboxy-terminal CH3 (located at the base of the Y's stem). A short region, known as the “switch”, connects the heavy chain variable and constant regions. The “hinge” connects CH2 and CH3 domains to the rest of the antibody. Two disulfide bonds in this hinge region connect the two heavy chain polypeptides to one another in an intact antibody. Each light chain comprises two domains—an amino-terminal variable (VL) domain, followed by a carboxy-terminal constant (CL) domain, separated from one another by another “switch.” Intact antibody tetramers comprise two heavy chain-light chain dimers in which the heavy and light chains are linked to one another by a single disulfide bond; two other disulfide bonds connect the heavy chain hinge regions to one another, so that the dimers are connected to one another and a tetramer is formed. Naturally-produced antibodies are also glycosylated, typically on the CH2 domain. Each domain in a natural antibody has a structure characterized by an “immunoglobulin fold” formed from two beta sheets (e.g., 3-, 4-, or 5-stranded sheets) packed against each other in a compressed antiparallel beta barrel. Each variable domain contains three hypervariable loops known as “complementarity determining regions” (CDR1, CDR2, and CDR3) and four somewhat invariant “framework” regions (FR1, FR2, FR3, and FR4). When natural antibodies fold, the FR regions form the beta sheets that provide the structural framework for the domains, and the CDR loop regions from both the heavy and light chains are brought together in three-dimensional space so that they create a single hypervariable antigen binding site located at the tip of the Y structure. The Fc region of naturally-occurring antibodies binds to elements of the complement system, and also to receptors on effector cells, including, for example, effector cells that mediate cytotoxicity. Affinity and/or other binding attributes of Fc regions for Fc receptors can be modulated through glycosylation or other modification. In some embodiments, antibodies produced and/or utilized in accordance with the present invention (e.g., as a component of a CAR) include glycosylated Fc domains, including Fc domains with modified or engineered glycosylation. In some embodiments, any polypeptide or complex of polypeptides that includes sufficient immunoglobulin domain sequences as found in natural antibodies can be referred to and/or used as an “antibody,” whether such polypeptide is naturally produced (e.g., generated by an organism reacting to an antigen), or produced by recombinant engineering, chemical synthesis, or other artificial system or methodology. In some embodiments, an antibody is polyclonal. In some embodiments, an antibody is monoclonal. In some embodiments, an antibody has constant region sequences that are characteristic of mouse, rabbit, primate, or human antibodies. In some embodiments, antibody sequence elements are humanized, primatized, chimeric, etc., as is known in the art. Moreover, the term “antibody,” as used herein, can refer in appropriate embodiments (unless otherwise stated or clear from context) to any of the art-known or developed constructs or formats for utilizing antibody structural and functional features in alternative presentation. For example, in some embodiments, an antibody utilized in accordance with the present invention is in a format selected from, but not limited to, intact IgA, IgG, IgE or IgM antibodies; bi- or multi-specific antibodies (e.g., Zybodies®, etc.); antibody fragments such as is used herein in the broadest sense and encompasses various antibody structures, including but not limited to monoclonal antibodies, polyclonal antibodies, multispecific antibodies (e.g., bispecific antibodies), and/or antibody fragments (preferably those fragments that exhibit the desired antigen-binding activity). An antibody described herein can be an immunoglobulin, heavy chain antibody, light chain antibody, LRR-based antibody, or other protein scaffold with antibody-like properties, as well as other immunological binding moiety known in the art, including, e.g., a Fab, Fab′, Fab′2, Fab2, Fab3, F(ab′)2, Fd, Fv, Feb, scFv, SMIP, antibody, diabody, triabody, tetrabody, minibody, maxibody, tandab, DVD, BiTe, TandAb, or the like, or any combination thereof. The subunit structures and three-dimensional configurations of different classes of antibodies are known in the art. In some embodiments, an antibody may lack a covalent modification (e.g., attachment of a glycan) that it would have if produced naturally. In some embodiments, an antibody may contain a covalent modification (e.g., attachment of a glycan, a payload [e.g., a detectable moiety, a therapeutic moiety, a catalytic moiety, etc.], or other pendant group [e.g., poly-ethylene glycol, etc.].
Antigen-binding fragment: An “antigen-binding fragment” refers to a portion of an intact antibody that binds the antigen to which the intact antibody binds. An antigen-binding fragment of an antibody includes any naturally occurring, enzymatically obtainable, synthetic, or genetically engineered polypeptide or glycoprotein that specifically binds an antigen to form a complex. Exemplary antibody fragments include, but are not limited to, Fv, Fab, Fab′, Fab′-SH, F(ab′)2; diabodies; linear antibodies; single-chain antibody molecules (e.g., scFv or VHH or VH or VL domains only); and multispecific antibodies formed from antibody fragments. In some embodiments, the antigen-binding fragments of the antibodies described herein are scFvs. In some embodiments, the antigen-binding fragments of the antibodies described herein are VHH domains only. As with full antibody molecules, antigen-binding fragments may be mono-specific or multispecific (e.g., bispecific). A multispecific antigen-binding fragment of an antibody may comprise at least two different variable domains, wherein each variable domain is capable of specifically binding to a separate antigen or to a different epitope of the same antigen.
Antibody heavy chain: As used herein, the term “antibody heavy chain” refers to the larger of the two types of polypeptide chains present in all antibody molecules in their naturally occurring conformations.
Antibody light chain: As used herein, the term “antibody light chain” refers to the smaller of the two types of polypeptide chains present in all antibody molecules in their naturally occurring conformations.
Synthetic antibody: As used herein, the term “synthetic antibody” refers to an antibody that is generated using recombinant DNA technology, such as, for example, an antibody expressed by a bacteriophage as described herein. The term should also be construed to mean an antibody which has been generated by the synthesis of a DNA molecule encoding the antibody and which DNA molecule expresses an antibody protein, or an amino acid sequence specifying the antibody, wherein the DNA or amino acid sequence has been obtained using synthetic DNA or amino acid sequence technology which is available and well known in the art.
Antigen: As used herein, the term “antigen” or “Ag” refers to a molecule that is capable of provoking an immune response. This immune response may involve either antibody production, the activation of specific immunologically-competent cells, or both. A skilled artisan will understand that any macromolecule, including virtually all proteins or peptides, can serve as an antigen. Furthermore, antigens can be derived from recombinant or genomic DNA. A skilled artisan will understand that any DNA that comprises a nucleotide sequences or a partial nucleotide sequence encoding a protein that elicits an immune response encodes an “antigen” as that term is used herein. Furthermore, one skilled in the art will understand that an antigen need not be encoded solely by a full length nucleotide sequence of a gene. It is readily apparent that the present invention includes, but is not limited to, the use of partial nucleotide sequences of more than one gene and that these nucleotide sequences are arranged in various combinations to elicit the desired immune response. Moreover, a skilled artisan will understand that an antigen need not be encoded by a “gene” at all. It is readily apparent that an antigen can be generated synthesized or can be derived from a biological sample. Such a biological sample can include, but is not limited to a tissue sample, a tumor sample, a cell or a biological fluid.
Autologous: As used herein, the term “autologous” refers to any material derived from an individual to which it is later to be re-introduced into the same individual.
Allogeneic: As used herein, the term “allogeneic” refers to any material (e.g., a population of cells) derived from a different animal of the same species.
Xenogeneic: As used herein, the term “xenogeneic” refers to any material (e.g., a population of cells) derived from an animal of a different species.
Cancer: As used herein, the term “cancer” refers to a disease characterized by the rapid and uncontrolled growth of aberrant cells. Cancer cells can spread locally or through the bloodstream and lymphatic system to other parts of the body. Examples of various cancers include but are not limited to, breast cancer, prostate cancer, ovarian cancer, cervical cancer, skin cancer, pancreatic cancer, colorectal cancer, renal cancer, liver cancer, brain cancer, lymphoma, leukemia, lung cancer and the like. In certain embodiments, the cancer is medullary thyroid carcinoma.
Conservative sequence modifications: As used herein, the term “conservative sequence modifications” refers to amino acid modifications that do not significantly affect or alter the binding characteristics of an antibody containing the amino acid sequence. Such conservative modifications include amino acid substitutions, additions and deletions. Modifications can be introduced into an antibody compatible with various embodiments by standard techniques known in the art, such as site-directed mutagenesis and PCR-mediated mutagenesis. Conservative amino acid substitutions are ones in which an amino acid residue is replaced with an amino acid residue having a similar side chain. Families of amino acid residues having similar side chains have been defined in the art. These families include amino acids with basic side chains (e.g., lysine, arginine, histidine), acidic side chains (e.g., aspartic acid, glutamic acid), uncharged polar side chains (e.g., glycine, asparagine, glutamine, serine, threonine, tyrosine, cysteine, tryptophan), nonpolar side chains (e.g., alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine), beta-branched side chains (e.g., threonine, valine, isoleucine) and aromatic side chains (e.g., tyrosine, phenylalanine, tryptophan, histidine). Thus, one or more amino acid residues within the CDR regions of an antibody can be replaced with other amino acid residues from the same side chain family and the altered antibody can be tested for the ability to bind antigens using the functional assays described herein.
Co-stimulatory ligand: As used herein, the term “co-stimulatory ligand” refers to a molecule on an antigen presenting cell (e.g., an APC, dendritic cell, B cell, and the like) that specifically binds a cognate co-stimulatory molecule on an immune cell (e.g., a T lymphocyte), thereby providing a signal which mediates an immune cell response, including, but not limited to, proliferation, activation, differentiation, and the like. A co-stimulatory ligand can include, but is not limited to, CD7, B7-1 (CD80), B7-2 (CD86), CD28, PD-L1, PD-L2, 4-1BBL, OX40L, inducible costimulatory ligand (ICOS-L), intercellular adhesion molecule (ICAM), CD30L, CD40, CD70, CD83, HLA-G, MICA, MICB, HVEM, lymphotoxin beta receptor, 3/TR6, ILT3, ILT4, HVEM, an agonist or antibody that binds Toll ligand receptor and a ligand that specifically binds with B7-H3. A co-stimulatory ligand also encompasses, inter alia, an antibody that specifically binds with a co-stimulatory molecule present on an immune cell (e.g., a T lymphocyte), such as, but not limited to, CD27, CD28, 4-1BB, OX40, CD30, CD40, PD-1, ICOS, lymphocyte function-associated antigen-1 (LFA-1), CD2, CD7, LIGHT, NKG2C, B7-H3, and a ligand that specifically binds with CD83.
Cytotoxic: As used herein, the term “cytotoxic” or “cytotoxicity” refers to killing or damaging cells. In one embodiment, cytotoxicity of the metabolically enhanced cells is improved, e.g. increased cytolytic activity of immune cells (e.g., T lymphocytes).
Effective amount: As used herein, an “effective amount” as described herein refers to a dose that is adequate to prevent or treat cancer in an individual. Amounts effective for a therapeutic or prophylactic use will depend on, for example, the stage and severity of the disease or disorder being treated, the age, weight, and general state of health of the patient, and the judgment of the prescribing physician. The size of the dose will also be determined by active selection, method of administration, timing and frequency of administration, the existence, nature, and extent of any adverse side-effects that might accompany the administration of a particular active, and the desired physiological effect. It will be appreciated by one of skill in the art that various diseases or disorders could require prolonged treatment involving multiple administrations, perhaps using the inventive CAR construct materials in each or various rounds of administration. By way of example and not intending to limit the invention, when the inventive CAR construct material is a host cell, an exemplary dose of host cells may be a minimum of one million cells (1×106 cells/dose).
For purposes of the invention, the amount or dose of an agent comprising an immune cell containing a CAR construct described herein administered should be sufficient to effect a therapeutic or prophylactic response in the subject or animal over a reasonable time frame. For example, the dose should be sufficient to bind to antigen, or detect, treat or prevent cancer in a period of from about 2 hours or longer, e.g., about 12 to about 24 or more hours, from the time of administration. In certain embodiments, the time period could be even longer. The dose will be determined by the efficacy of the particular inventive CAR construct material and the condition of the animal (e.g., human), as well as the body weight of the animal (e.g., human) to be treated.
Effector function: As used herein, “effector function” or “effector activity” refers to a specific activity carried out by an immune cell in response to stimulation of the immune cell. For example, an effector function of a T lymphocyte includes, without limitation, recognizing an antigen and/or killing a cell that expresses a recognized antigen.
Encoding: As used herein, “encoding” refers to the inherent property of specific sequences of nucleotides in a polynucleotide, such as a gene, a cDNA, or an mRNA, to serve as templates for synthesis of other polymers and macromolecules in biological processes having either a defined sequence of nucleotides (i.e., rRNA, tRNA and mRNA) or a defined sequence of amino acids and the biological properties resulting therefrom. Thus, a gene encodes a protein if transcription and translation of mRNA corresponding to that gene produces the protein in a cell or other biological system. Both the coding strand, the nucleotide sequence of which is identical to the mRNA sequence and is usually provided in sequence listings, and the non-coding strand, used as the template for transcription of a gene or cDNA, can be referred to as encoding the protein or other product of that gene or cDNA.
Endogenous: As used herein “endogenous” refers to any material from or produced inside a particular organism, cell, tissue or system.
Exogenous: As used herein, the term “exogenous” refers to any material introduced from or produced outside a particular organism, cell, tissue or system.
Expand: As used herein, the term “expand” refers to increasing in number, as in an increase in the number of cells, for example, immune cells, e.g., T lymphocytes, and/or hematopoietic cells. In one embodiment, immune cells, e.g., T lymphocytes, and/or hematopoietic cells that are expanded ex vivo increase in number relative to the number originally present in a culture. In another embodiment, immune cells, e.g., T lymphocytes, and/or hematopoietic cells that are expanded ex vivo increase in number relative to other cell types in a culture. In some embodiments, expansion may occur in vivo. The term “ex vivo,” as used herein, refers to cells that have been removed from a living organism, (e.g., a human) and propagated outside the organism (e.g., in a culture dish, test tube, or bioreactor).
Expression: As used herein, the term “expression” of a nucleic acid sequence refers to generation of any gene product from a nucleic acid sequence. In some embodiments, a gene product can be a transcript. In some embodiments, a gene product can be a polypeptide. In some embodiments, expression of a nucleic acid sequence involves one or more of the following: (1) production of an RNA template from a DNA sequence (e.g., by transcription); (2) processing of an RNA transcript (e.g., by splicing, editing, 5′ cap formation, and/or 3′ end formation); (3) translation of an RNA into a polypeptide or protein; and/or (4) post-translational modification of a polypeptide or protein.
Expression vector: As used herein, the term “expression vector” or “recombinant expression vector” refers to a vector comprising a recombinant polynucleotide comprising expression control sequences operatively linked to a nucleotide sequence to be expressed. An expression vector comprises sufficient cis-acting elements for expression; other elements for expression can be supplied by the host cell or in an in vitro expression system. Expression vectors include all those known in the art, such as cosmids, plasmids (e.g., naked or contained in liposomes) and viruses (e.g., lentiviruses, retroviruses, adenoviruses, and adeno-associated viruses).
Fragment: As used herein, the terms “fragment” or “portion” refers to a structure that includes a discrete portion of the whole, but lacks one or more moieties found in the whole structure. In some embodiments, a fragment consists of such a discrete portion. In some embodiments, a fragment consists of or comprises a characteristic structural element or moiety found in the whole. In some embodiments, a nucleotide fragment comprises or consists of at least 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 275, 300, 325, 350, 375, 400, 425, 450, 475, 500, or more monomeric units (e.g., nucleic acids) as found in the whole nucleotide. In some embodiments, a nucleotide fragment comprises or consists of at least about 5%, 10%, 15%, 20%, 25%, 30%, 25%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or more of the monomeric units (e.g., residues) found in the whole nucleotide. The whole material or entity may in some embodiments be referred to as the “parent” of the whole.
Functional Portion: As used herein, the term “functional portion” when used in reference to a CAR refers to any part or fragment of the CAR constructs of the invention, which part or fragment retains the biological activity of the CAR construct of which it is a part (the parent CAR construct). Functional portions encompass, for example, those parts of a CAR construct that retain the ability to recognize target cells, or detect, treat, or prevent cancer, to a similar extent, the same extent, or to a higher extent, as the parent CAR construct. In reference to the parent CAR construct, the functional portion can comprise, for instance, about 10%, about 25%, about 30%, about 50%, about 68%, about 80%, about 90%, about 95%, or more, of the parent CAR.
The functional portion can comprise additional amino acids at the amino or carboxy terminus of the portion, or at both termini, which additional amino acids are not found in the amino acid sequence of the parent CAR construct. Desirably, the additional amino acids do not interfere with the biological function of the functional portion, e.g., recognize target cells, detect cancer, treat or prevent cancer, etc. More desirably, the additional amino acids enhance the biological activity as compared to the biological activity of the parent CAR construct.
Functional Variant: As used herein, the term “functional variant,” as used herein, refers to a CAR construct, polypeptide, or protein having substantial or significant sequence identity or similarity to a parent CAR construct, which functional variant retains the biological activity of the CAR of which it is a variant. Functional variants encompass, for example, those variants of the CAR construct described herein (the parent CAR construct) that retain the ability to recognize target cells to a similar extent, the same extent, or to a higher extent, as the parent CAR construct. In reference to the parent CAR construct, the functional variant can, for instance, be at least about 30%, about 50%, about 75%, about 80%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, about 99% or more identical in amino acid sequence to the parent CAR construct.
A functional variant can, for example, comprise the amino acid sequence of the parent CAR with at least one conservative amino acid substitution. Alternatively or additionally, the functional variants can comprise the amino acid sequence of the parent CAR construct with at least one non-conservative amino acid substitution. In this case, it is preferable for the non-conservative amino acid substitution to not interfere with or inhibit the biological activity of the functional variant. The non-conservative amino acid substitution may enhance the biological activity of the functional variant, such that the biological activity of the functional variant is increased as compared to the parent CAR construct.
Homology: As used herein, the term “homology” refers to the overall relatedness between polymeric molecules, e.g., between nucleic acid molecules (e.g., DNA molecules and/or RNA molecules) and/or between polypeptide molecules. In some embodiments, polymeric molecules are considered to be “homologous” to one another if their sequences are at least 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 99% identical. In some embodiments, polymeric molecules are considered to be “homologous” to one another if their sequences are at least 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 99% similar (e.g., containing residues with related chemical properties at corresponding positions). As will be understood by those skilled in the art, a variety of algorithms are available that permit comparison of sequences in order to determine their degree of homology, including by permitting gaps of designated length in one sequence relative to another when considering which residues “correspond” to one another in different sequences. Calculation of the percent homology between two nucleic acid sequences, for example, can be performed by aligning the two sequences for optimal comparison purposes (e.g., gaps can be introduced in one or both of a first and a second nucleic acid sequences for optimal alignment and non-corresponding sequences can be disregarded for comparison purposes). In certain embodiments, the length of a sequence aligned for comparison purposes is at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or substantially 100% of the length of the reference sequence. The nucleotides at corresponding nucleotide positions are then compared. When a position in the first sequence is occupied by the same nucleotide as the corresponding position in the second sequence, then the molecules are identical at that position; when a position in the first sequence is occupied by a similar nucleotide as the corresponding position in the second sequence, then the molecules are similar at that position. The percent homology between the two sequences is a function of the number of identical and similar positions shared by the sequences, taking into account the number of gaps, and the length of each gap, which needs to be introduced for optimal alignment of the two sequences.
Identity: As used herein, the term “identity” refers to the subunit sequence identity between two polymeric molecules particularly between two amino acid molecules, such as, between two polypeptide molecules. When two amino acid sequences have the same residues at the same positions; e.g., if a position in each of two polypeptide molecules is occupied by an arginine, then they are identical at that position. The identity or extent to which two amino acid sequences have the same residues at the same positions in an alignment is often expressed as a percentage. The identity between two amino acid sequences is a direct function of the number of matching or identical positions; e.g., if half (e.g., five positions in a polymer ten amino acids in length) of the positions in two sequences are identical, the two sequences are 50% identical; if 90% of the positions (e.g., 9 of 10), are matched or identical, the two amino acids sequences are 90% identical.
Substantial identity: As used herein, the term “substantial identity” refers to a comparison between amino acid or nucleic acid sequences. As will be appreciated by those of ordinary skill in the art, two sequences are generally considered to be “substantially identical” if they contain identical residues in corresponding positions. As is well known in this art, amino acid or nucleic acid sequences may be compared using any of a variety of algorithms, including those available in commercial computer programs such as BLASTN for nucleotide sequences and BLASTP, gapped BLAST, and PSI-BLAST for amino acid sequences. In some embodiments, two sequences are considered to be substantially identical if at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more of their corresponding residues are identical over a relevant stretch of residues. In some embodiments, the relevant stretch is a complete sequence. In some embodiments, the relevant stretch is at least 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 125, 150, 175, 200, 225, 250, 275, 300, 325, 350, 375, 400, 425, 450, 475, 500 or more residues. In the context of a CDR, reference to “substantial identity” typically refers to a CDR having an amino acid sequence at least 80%, preferably at least 85%, at least 90%, at least 95%, at least 98% or at least 99% identical to that of a reference CDR.
Immune cell: As used herein, the term “immune cell,” refers to a cell that is involved in an immune response, e.g., promotion of an immune response. Examples of immune cells include, but are not limited to, T-lymphocytes, natural killer (NK) cells, macrophages, monocytes, dendritic cells, neutrophils, eosinophils, mast cells, platelets, large granular lymphocytes, Langerhans' cells, or B-lymphocytes. A source of immune cells (e.g., T lymphocytes) can be obtained from a subject.
Immune response: As used herein the term “immune response” refers to a cellular and/or systemic response to an antigen that occurs when lymphocytes identify antigenic molecules as foreign and induce the formation of antibodies and/or activate lymphocytes to remove the antigen.
Immunoglobulin: As used herein, the term “immunoglobulin” or “Ig,” refers to a class of proteins that function as antibodies. Antibodies expressed by B cells are sometimes referred to as a BCR (B cell receptor) or antigen receptor. The five members included in this class of proteins are IgA, IgG, IgM, IgD, and IgE. IgA is the primary antibody that is present in body secretions, such as saliva, tears, breast milk, gastrointestinal secretions and mucus secretions of the respiratory and genitourinary tracts. IgG is the most common circulating antibody. IgM is the main immunoglobulin produced in the primary immune response in most subjects. It is the most efficient immunoglobulin in agglutination, complement fixation, and other antibody responses, and is important in defense against bacteria and viruses. IgD is an immunoglobulin that has no known antibody function, but may serve as an antigen receptor. IgE is an immunoglobulin that mediates immediate hypersensitivity by causing release of mediators from mast cells and basophils upon exposure to allergen.
Isolated: As used herein, the term “isolated” refers to something altered or removed from the natural state. For example, a nucleic acid or a peptide naturally present in a living animal is not “isolated,” but the same nucleic acid or peptide partially or completely separated from the coexisting materials of its natural state is “isolated.” An isolated nucleic acid or protein can exist in substantially purified form, or can exist in a non-native environment such as, for example, a host cell.
Modified: As used herein, the term “modified” refers to a changed state or structure of a molecule or cell of the invention. Molecules may be modified in many ways, including chemically, structurally, and functionally. Cells may be modified through the introduction of nucleic acids.
Modulating: As used herein the term “modulating,” refers to mediating a detectable increase or decrease in the level of a response and/or a change in the nature of a response in a subject compared with the level and/or nature of a response in the subject in the absence of a treatment or compound, and/or compared with the level and/or nature of a response in an otherwise identical but untreated subject. The term encompasses perturbing and/or affecting a native signal or response thereby mediating a beneficial therapeutic response in a subject, preferably, a human.
Monoclonal Antibody: A “monoclonal antibody” or “mAb” refers to an antibody obtained from a population of substantially homogeneous antibodies, i.e., the individual antibodies comprising the population are identical and/or bind the same epitope, except for possible variant antibodies (e.g., containing naturally occurring mutations or arising during production of a monoclonal antibody preparation), such variants generally being present in minor amounts. In contrast to polyclonal antibody preparations, which typically include different antibodies directed against different determinants (epitopes), each monoclonal antibody of a monoclonal antibody preparation is directed against a single determinant on an antigen.
Nucleic acid: As used herein, the term “nucleic acid” refers to a polymer of at least three nucleotides. In some embodiments, a nucleic acid comprises DNA. In some embodiments, a nucleic acid comprises RNA. In some embodiments, a nucleic acid is single stranded. In some embodiments, a nucleic acid is double stranded. In some embodiments, a nucleic acid comprises both single and double stranded portions. In some embodiments, a nucleic acid comprises a backbone that comprises one or more phosphodiester linkages. In some embodiments, a nucleic acid comprises a backbone that comprises both phosphodiester and non-phosphodiester linkages. For example, in some embodiments, a nucleic acid may comprise a backbone that comprises one or more phosphorothioate or 5′-N-phosphoramidite linkages and/or one or more peptide bonds, e.g., as in a “peptide nucleic acid.” In some embodiments, a nucleic acid comprises one or more, or all, natural residues (e.g., adenine, cytosine, deoxyadenosine, deoxycytidine, deoxyguanosine, deoxythymidine, guanine, thymine, uracil). In some embodiments, a nucleic acid comprises one or more, or all, non-natural residues. In some embodiments, a non-natural residue comprises a nucleoside analog (e.g., 2-aminoadenosine, 2-thiothymidine, inosine, pyrrolo-pyrimidine, 3-methyl adenosine, 5-methylcytidine, C-5 propynyl-cytidine, C-5 propynyl-uridine, 2-aminoadenosine, C5-bromouridine, C5-fluorouridine, C5-iodouridine, C5-propynyl-uridine, C5-propynyl-cytidine, C5-methylcytidine, 2-aminoadenosine, 7-deazaadenosine, 7-deazaguanosine, 8-oxoadenosine, 8-oxoguanosine, 0(6)-methylguanine, 2-thiocytidine, methylated bases, intercalated bases, and combinations thereof). In some embodiments, a non-natural residue comprises one or more modified sugars (e.g., 2′-fluororibose, ribose, 2′-deoxyribose, arabinose, and hexose) as compared to those in natural residues. In some embodiments, a nucleic acid has a nucleotide sequence that encodes a functional gene product such as an RNA or polypeptide. In some embodiments, a nucleic acid has a nucleotide sequence that comprises one or more introns. In some embodiments, a nucleic acid may be prepared by isolation from a natural source, enzymatic synthesis (e.g., by polymerization based on a complementary template, e.g., in vivo or in vitro, reproduction in a recombinant cell or system, or chemical synthesis. In some embodiments, a nucleic acid is at least 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 225, 250, 275, 300, 325, 350, 375, 400, 425, 450, 475, 500, 600, 700, 800, 900, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000 or more residues long.
Operably linked: As used herein, the term “operably linked” refers to functional linkage between, for example, a regulatory sequence and a heterologous nucleic acid sequence resulting in expression of the latter. For example, a first nucleic acid sequence is operably linked with a second nucleic acid sequence when the first nucleic acid sequence is placed in a functional relationship with the second nucleic acid sequence. For instance, a promoter is operably linked to a coding sequence if the promoter affects the transcription or expression of the coding sequence. Generally, operably linked DNA sequences are contiguous and, where necessary to join two protein coding regions, in the same reading frame.
Polynucleotide: As used herein, the term “polynucleotide” refers to a chain of nucleotides. Furthermore, nucleic acids are polymers of nucleotides. Thus, nucleic acids and polynucleotides as used herein are interchangeable. One skilled in the art has the general knowledge that nucleic acids are polynucleotides, which can be hydrolyzed into the monomeric “nucleotides.” The monomeric nucleotides can be hydrolyzed into nucleosides. As used herein polynucleotides include, but are not limited to, all nucleic acid sequences which are obtained by any means available in the art, including, without limitation, recombinant means, i.e., the cloning of nucleic acid sequences from a recombinant library or a cell genome, using ordinary cloning technology and PCR, and the like, and by synthetic means.
Polypeptide: As used herein, the term “polypeptide” refers to any polymeric chain of residues (e.g., amino acids) that are typically linked by peptide bonds. In some embodiments, a polypeptide has an amino acid sequence that occurs in nature. In some embodiments, a polypeptide has an amino acid sequence that does not occur in nature. In some embodiments, a polypeptide has an amino acid sequence that is engineered in that it is designed and/or produced through action of the hand of man. In some embodiments, a polypeptide may comprise or consist of natural amino acids, non-natural amino acids, or both. In some embodiments, a polypeptide may comprise or consist of only natural amino acids or only non-natural amino acids. In some embodiments, a polypeptide may comprise D-amino acids, L-amino acids, or both. In some embodiments, a polypeptide may comprise only D-amino acids. In some embodiments, a polypeptide may comprise only L-amino acids. In some embodiments, a polypeptide may include one or more pendant groups or other modifications, e.g., modifying or attached to one or more amino acid side chains, at the polypeptide's N-terminus, at the polypeptide's C-terminus, or any combination thereof. In some embodiments, such pendant groups or modifications may be selected from the group consisting of acetylation, amidation, lipidation, methylation, pegylation, etc., including combinations thereof. In some embodiments, a polypeptide may be cyclic, and/or may comprise a cyclic portion. In some embodiments, a polypeptide is not cyclic and/or does not comprise any cyclic portion. In some embodiments, a polypeptide is linear. In some embodiments, a polypeptide may be or comprise a stapled polypeptide. In some embodiments, the term “polypeptide” may be appended to a name of a reference polypeptide, activity, or structure; in such instances it is used herein to refer to polypeptides that share the relevant activity or structure and thus can be considered to be members of the same class or family of polypeptides. For each such class, the present specification provides and/or those skilled in the art will be aware of exemplary polypeptides within the class whose amino acid sequences and/or functions are known; in some embodiments, such exemplary polypeptides are reference polypeptides for the polypeptide class or family. In some embodiments, a member of a polypeptide class or family shows significant sequence homology or identity with, shares a common sequence motif (e.g., a characteristic sequence element) with, and/or shares a common activity (in some embodiments at a comparable level or within a designated range) with a reference polypeptide of the class; in some embodiments with all polypeptides within the class). For example, in some embodiments, a member polypeptide shows an overall degree of sequence homology or identity with a reference polypeptide that is at least about 30-40%, and is often greater than about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more and/or includes at least one region (e.g., a conserved region that may in some embodiments be or comprise a characteristic sequence element) that shows very high sequence identity, often greater than 90% or even 95%, 96%, 97%, 98%, or 99%. Such a conserved region usually encompasses at least 3-4 and often up to 20 or more amino acids; in some embodiments, a conserved region encompasses at least one stretch of at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 or more contiguous amino acids. In some embodiments, a useful polypeptide may comprise or consist of a fragment of a parent polypeptide. In some embodiments, a useful polypeptide as may comprise or consist of a plurality of fragments, each of which is found in the same parent polypeptide in a different spatial arrangement relative to one another than is found in the polypeptide of interest (e.g., fragments that are directly linked in the parent may be spatially separated in the polypeptide of interest or vice versa, and/or fragments may be present in a different order in the polypeptide of interest than in the parent), so that the polypeptide of interest is a derivative of its parent polypeptide.
Protein: As used herein, the term “protein” refers to a polypeptide (i.e., a string of at least two amino acids linked to one another by peptide bonds). Proteins may include moieties other than amino acids (e.g., may be glycoproteins, proteoglycans, etc.) and/or may be otherwise processed or modified. Those of ordinary skill in the art will appreciate that a “protein” can be a complete polypeptide chain as produced by a cell (with or without a signal sequence), or can be a characteristic portion thereof. Those of ordinary skill will appreciate that a protein can sometimes include more than one polypeptide chain, for example linked by one or more disulfide bonds or associated by other means. Polypeptides may contain L-amino acids, D-amino acids, or both and may contain any of a variety of amino acid modifications or analogs known in the art. Useful modifications include, e.g., terminal acetylation, amidation, methylation, etc. In some embodiments, proteins may comprise natural amino acids, non-natural amino acids, synthetic amino acids, and combinations thereof. The term “peptide” is generally used to refer to a polypeptide having a length of less than about 100 amino acids, less than about 50 amino acids, less than 20 amino acids, or less than 10 amino acids. In some embodiments, proteins are antibodies, antibody fragments, biologically active portions thereof, and/or characteristic portions thereof.
Signal transduction pathway: As used herein, the term “signal transduction pathway” refers to the biochemical relationship between a variety of signal transduction molecules that play a role in the transmission of a signal from one portion of a cell to another portion of a cell. The phrase “cell surface receptor” includes molecules and complexes of molecules capable of receiving a signal and transmitting signal across the plasma membrane of a cell.
Single chain antibodies: As used herein, the term “single chain antibodies” refers to antibodies formed by recombinant DNA techniques in which immunoglobulin heavy and light chain fragments are linked to the Fv region via an engineered span of amino acids. Various methods of generating single chain antibodies are known, including those described in U.S. Pat. No. 4,694,778; Bird (1988) Science 242:423-442; Huston et al. (1988) Proc. Natl. Acad. Sci. USA 85:5879-5883; Ward et al. (1989) Nature 334:54454; Skerra et al. (1988) Science 242:1038-1041.
Specifically binds: As used herein, the term “specifically binds,” with respect to an antigen binding domain, such as an antibody agent, refers to an antigen binding domain or antibody agent which recognizes a specific antigen, but does not substantially recognize or bind other molecules in a sample. For example, an antigen binding domain or antibody agent that specifically binds to an antigen from one species may also bind to that antigen from one or more species. But, such cross-species reactivity does not itself alter the classification of an antigen binding domain or antibody agent as specific. In another example, an antigen binding domain or antibody agent that specifically binds to an antigen may also bind to different allelic forms of the antigen. However, such cross reactivity does not itself alter the classification of an antigen-binding domain or antibody agent as specific. In some instances, the terms “specific binding” or “specifically binding,” can be used in reference to the interaction of an antigen binding domain or antibody agent, a protein, or a peptide with a second chemical species, to mean that the interaction is dependent upon the presence of a particular structure (e.g., an antigenic determinant or epitope) on the chemical species; for example, an antigen binding domain or antibody agent recognizes and binds to a specific protein structure rather than to proteins generally. If an antigen binding domain or antibody agent is specific for epitope “A”, the presence of a molecule containing epitope A (or free, unlabeled A), in a reaction containing labeled “A” and the antigen binding domain or antibody agent, will reduce the amount of labeled A bound to the antibody.
Subject: As used herein, the term “subject” refers to an organism, for example, a mammal (e.g., a human, a non-human mammal, a non-human primate, a primate, a laboratory animal, a mouse, a rat, a hamster, a gerbil, a cat, or a dog). In some embodiments a human subject is an adult, adolescent, or pediatric subject. In some embodiments, a subject is suffering from a disease, disorder or condition, e.g., a disease, disorder, or condition that can be treated as provided herein, e.g., a cancer or a tumor listed herein. In some embodiments, a subject is susceptible to a disease, disorder, or condition; in some embodiments, a susceptible subject is predisposed to and/or shows an increased risk (as compared to the average risk observed in a reference subject or population) of developing the disease, disorder, or condition. In some embodiments, a subject displays one or more symptoms of a disease, disorder, or condition. In some embodiments, a subject does not display a particular symptom (e.g., clinical manifestation of disease) or characteristic of a disease, disorder, or condition. In some embodiments, a subject does not display any symptom or characteristic of a disease, disorder, or condition. In some embodiments, a subject is a patient. In some embodiments, a subject is an individual to whom diagnosis and/or therapy is and/or has been administered.
Substantially purified: As used herein, the term “substantially purified”, for example as applied to a cell, refers to a cell that is essentially free of other cell types. A substantially purified cell also refers to a cell which has been separated from other cell types with which it is normally associated in its naturally occurring state. In some instances, a population of substantially purified cells refers to a homogenous population of cells. In other instances, this term refers simply to cell that have been separated from the cells with which they are naturally associated in their natural state. In some embodiments, the cells are cultured in vitro. In other embodiments, the cells are not cultured in vitro.
Target: As used herein, the term “target” refers to a cell, tissue, organ, or site within the body that is the subject of provided methods, systems, and/or compositions, for example, a cell, tissue, organ or site within a body that is in need of treatment or is preferentially bound by, for example, an antibody (or fragment thereof) or a CAR.
Target site: As used herein, the term “target site” or “target sequence” refers to a genomic nucleic acid sequence that defines a portion of a nucleic acid to which a binding molecule (e.g., an antigen-binding domain of a CAR) may specifically bind under conditions sufficient for binding to occur.
T cell receptor: As used herein, the term “T cell receptor” or “TCR” refers to a complex of membrane proteins that participate in the activation of T cells in response to the presentation of antigen. A TCR is responsible for recognizing antigens bound to major histocompatibility complex molecules. A TCR comprises a heterodimer of an alpha (α) and beta (β) chain, although in some cells the TCR comprises gamma and delta (γ/δ) chains. TCRs may exist in alpha/beta and gamma/delta forms, which are structurally similar but have distinct anatomical locations and functions. Each chain comprises two extracellular domains, a variable and constant domain. In some embodiments, a TCR may be modified on any cell comprising a TCR, including, for example, a helper T cell, a cytotoxic T cell, a memory T cell, regulatory T cell, natural killer T cell, and gamma delta T cell.
Therapeutic: As used herein, the term “therapeutic” refers to a treatment and/or prophylaxis. A therapeutic effect is obtained by suppression, remission, or eradication of a disease state.
Transfected: As used herein, the term “transfected” or “transformed” or “transduced” refers to a process by which exogenous nucleic acid is transferred or introduced into the host cell. A “transfected” or “transformed” or “transduced” cell is one which has been transfected, transformed or transduced with exogenous nucleic acid. The cell includes the primary subject cell and its progeny.
Treat: As used herein, the term “treat,” “treatment,” or “treating” refers to partial or complete alleviation, amelioration, delay of onset of, inhibition, relief, and/or reduction in incidence and/or severity of one or more symptoms or features of a disease, disorder, and/or condition. In some embodiments, treatment may be administered to a subject who does not exhibit signs or features of a disease, disorder, and/or condition (e.g., may be prophylactic). In some embodiments, treatment may be administered to a subject who exhibits only early or mild signs or features of the disease, disorder, and/or condition, for example for the purpose of decreasing the risk of developing pathology associated with the disease, disorder, and/or condition. In some embodiments, treatment may be administered to a subject who exhibits established, severe, and/or late-stage signs of the disease, disorder, or condition. In some embodiments, treating may comprise administering to an immune cell (e.g., a T lymphocyte) or contacting an immune cell with a modulator of a pathway activated by in vitro transcribed mRNA. In some embodiments, the methods are for prevention of a disease, disorder, and/or condition or prevention of one or more symptoms or features of a disease, disorder, and/or condition.
Tumor: As used herein, the term “tumor” refers to an abnormal growth of cells or tissue. In some embodiments, a tumor may comprise cells that are precancerous (e.g., benign), malignant, pre-metastatic, metastatic, and/or non-metastatic. In some embodiments, a tumor is associated with, or is a manifestation of, a cancer. In some embodiments, a tumor may be a disperse tumor or a liquid tumor. In some embodiments, a tumor may be a solid tumor.
Vector: As used herein, the term “vector” refers to a composition of matter that comprises an isolated nucleic acid and which can be used to deliver the isolated nucleic acid to the interior of a cell. Numerous vectors are known in the art including, but not limited to, linear polynucleotides, polynucleotides associated with ionic or amphiphilic compounds, plasmids, and viruses. Thus, the term “vector” includes an autonomously replicating plasmid or a virus. The term should also be construed to include non-plasmid and non-viral compounds which facilitate transfer of nucleic acid into cells, such as, for example, polylysine compounds, liposomes, and the like. Examples of viral vectors include, but are not limited to, adenoviral vectors, adeno-associated virus vectors, retroviral vectors, lentiviral vectors, and the like.
Throughout this disclosure, various aspects of the invention can be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 2.7, 3, 4, 5, 5.3, and 6. This applies regardless of the breadth of the range.
T cells expressing chimeric antigen receptors (CAR T-cells) have exhibited efficacious treatment of hematological malignancies. Upon antigen binding, CARs (chimeric antigen receptors) initiate Ca2+-dependent signaling pathways, leading to an increased intracellular concentration of nuclear factor of activated T cells (NFAT), which stimulates downstream T cell effector functions (see, e.g., Hogan, Cell Calcium. (2017) 63:66-9; Chow, Molecular and Cellular Biology, 1999; 19(3):2300-7). However, factors such as variable transduction efficiencies in introducing a construct encoding the CAR to a cell (e.g., a T cell) present significant challenges in comparing the relative activity and efficacy of the CAR to other CAR constructs. In addition, objective high-throughput platforms to compare CAR-induced T cell activity are also lacking making such comparative analyses time-consuming and limited in throughput. The instant disclosure is based, at least in part, on the development of a reporter construct that allows high-throughput CAR screening. The reporter constructs utilizes a reporter molecule under control of a minimal NFAT-sensitive promoter. This approach, termed “IL-2 Reporter System” (IRS), may be employed for the identification of functional CARs having a desired level of activity to improve development of CAR therapies.
The present disclosure provides nucleic acid constructs comprising a nucleotide sequence encoding a reporter molecule under the control of a minimal nuclear factor of activated T cells (NFAT)-responsive promoter. In some embodiments, the NFAT-responsive promoter comprises a plurality of NFAT binding sites. In some embodiments, the NFAT-responsive promoter is a minimal IL-2 promoter and comprises a TATA box. Provided herein are vectors comprising any of the nucleic acid constructs described herein, and reporter cell lines comprising any of the nucleic acid constructs or vectors described herein. Also provided herein are methods of using the reporter cell lines described herein to determine the ability of a chimeric antigen receptor (CAR) (e.g., a candidate CAR) to induce NFAT-signaling in a cell and activation of the cell.
Aspects of the present disclosure relate to nucleic acid constructs comprising a minimal nuclear factor of activated T cells (NFAT)-responsive promoter, which may be used, for example, to assess chimeric antigen receptors (CARs) and activation of a cell (e.g., T cells) expressing the CARs. CAR activation sets in motion an intracellular signaling pathway leading to T-cell activation and effector function of the T cell, which involves NFAT signaling and gene expression (see, e.g., Hogan, Cell Calcium. (2017) 63: 66-9). As used herein, the term “NFAT-responsive promoter” refers to a promoter region that is activated by NFAT signaling and promotes expression of a gene that is operably linked to the NFAT-responsive promoter upon activation. In some embodiments, the gene that is operably linked (under control of) the NFAT-responsive promoter encodes a reporter molecule.
Nuclear factor of activated T-cells (NFAT) is a family of transcription factors, include NFAT1-NFAT-5, that are involved in regulating immune responses, including regulating interleukin-2 (IL-2 expression) as well as T cell differentiation and self-tolerance. See, e.g., Macian Nat. Rev. Immunol. (2005) 5: 472-484. NFAT transcription factors comprise two components: a cytoplasmic Rel domain protein (NFAT family member) and a nuclear component comprising various transcription factors (Chow, Molecular and Cellular Biology, 1999; 19(3):2300-7). NFAT1 and NFAT2 are predominantly expressed in peripheral T cells that produce IL-2 and NFAT binding sites are generally found upstream (5′) of NFAT-regulated genes, such as IL-2. See, e.g., Chow, Molecular and Cellular Biology, (1999) 19(3):2300-7; Rooney et al., Molecular and Cellular Biology, (1995) 15(11):6299-310; and Shaw et al., Journal of Immunology, (2010) 185(9):4972-5, the entire contents of which are incorporated herein by reference.
As will be understood by one of ordinary skill in the art, in eukaryotic cells, a promoter operably linked to a gene typically includes a core promoter adjacent and 5′ to the transcription start site of the gene (coding sequence). Further upstream (5′) of the core promoter may be cis-regulatory regions, such as transcription factor binding site(s).
In some embodiments, the NFAT-responsive promoter comprises a plurality of NFAT-binding sites. In some embodiments, the NFAT-responsive promoter comprises least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 or more NFAT binding sites. In some embodiments, the NFAT-responsive promoter comprises six NFAT binding sites. In some embodiments, each of the NFAT binding sites of a NFAT-responsive promoter may be the same NFAT binding site (e.g., bind the same type of NFAT transcription factor) or be different NFAT binding sites (e.g., bind different types of NFAT transcription factors). In some embodiments, each of the NFAT binding site comprises the same nucleotide sequence. In some embodiments, the NFAT binding sites comprise different nucleotide sequence.
An example of a NFAT binding site is provided by the nucleotide sequence provided by SEQ ID NO: 1:
In some embodiments, at least one of the NFAT binding site comprises the nucleotide sequence of SEQ ID NO: 1. In some embodiments, each of the NFAT binding site comprises the nucleotide sequence of SEQ ID NO: 1.
Each of the NFAT binding sites are located immediately adjacent to one another (e.g., in tandem without any additional nucleotides between the NFAT binding sites). Alternatively, one or more additional nucleotides may be present between two or more of the NFAT binding sites.
In some embodiments, the NFAT-responsive promoter comprises an IL-2 promoter, or portion thereof. In some embodiments, the NFAT-responsive promoter comprises a minimal IL-2 promoter. In some embodiments, the NFAT-responsive promoter comprises the core IL-2 promoter. In general, the naturally occurring IL-2 promoter is relatively compact and includes a core promoter containing a TATA box and an upstream regulatory region. The core promoter is considered the region within approximately −40 and +40 nucleotides (e.g., 40 nucleotides upstream (5′) to 40 nucleotides downstream (3′)) of the transcription start site. See, e.g., Weaver et al. Mol. Immunol. (2007) 44(11) 2813-2819.
As used herein, the term “minimal IL-2 promoter” refers to the minimal portion of the IL-2 promoter required for transcription. In some embodiments, the minimal IL-2 promoter is the IL-2 core promoter. In some embodiments, the NFAT-responsive promoter comprises the core IL-2 promoter comprising a TATA box. A TATA box (also referred to as a “Goldberg-Hogness box”) is a T/A rich sequence found upstream of a transcriptional start site (Shi & Zhou, BMC Bioinformatics (2006) 7, Article number S2). In some embodiments, the TATA box comprises the consensus sequence 5′-TATA(A/T)A(A/T)-3′ (SEQ ID NO: 18). The TATA box is thought to be involved in formation of the preinitiation complex for gene transcription and bind a TATA-binding protein (TBP).
In some embodiments, the minimal IL-2 promoter comprises the nucleotide sequence of SEQ ID NO: 2.
An example of a minimal IL-2 promoter is provided by the nucleotide sequence provided by SEQ ID NO: 2:
In some embodiments, the NFAT binding sites are located 5′ (upstream) of the minimal IL-2 promoter. In some embodiments, the NFAT binding sites are located at least 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, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, or more nucleotides 5′ (upstream) of the minimal IL-2 promoter. In some embodiments, the NFAT responsive promoter comprises at least 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, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, or more nucleotides between the last NFAT binding site and the minimal IL-2 promoter.
An exemplary nucleotide sequence of a minimal NFAT-responsive promoter is provided by SEQ ID NO: 3. In some embodiments, the nucleotide sequence of the minimal NFAT-responsive promoter comprises, consists of, or consists essentially of the nucleotide sequence of SEQ ID NO: 3, or a sequence that is at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical the nucleotide sequence of SEQ ID NO: 3.
Exemplary nucleotide sequence of a minimal NFAT-responsive promoter comprising 6 NFAT binding sites (SEQ ID NO: 3):
Any of the nucleic acid constructs encoding an IL-2 reporter system described herein may further comprise a nucleotide sequence encoding a second reporter molecule operably linked (under the control of) to a constitutive promoter (also referred to as a constitutively active promoter). Preferably, the reporter molecule that is operably linked to the minimal NFAT-responsive promoter is different than the second reporter molecule operably linked to the constitutively active promoter, such that detection of the reporter molecule that is operably linked to the minimal NFAT-responsive promoter is indicative of activity of the NFAT-responsive promoter and detection of the reporter molecule that is operably linked to the constitutively active promoter is indicative of activity of the constitutively active promoter.
In some embodiments, the constitutive promoter controlling expression of the second reporter molecule is referred to as a “reference promoter.” Examples of constitutively active promoter include, without limitation, EF-1alpha (EF1α), CMV promoter, SV40 promoter, PGK1 promoter, Ubc promoter, beta actin promoter, CAG promoter, TRE promoter, UAS promoter, Ac5 promoter, polyhedrin promoter, and U6 promoter. In some embodiments, the constitutively active promoter is an EF1a promoter.
The nucleotide sequence of an elongation factor 1 alpha (EF-1alpha, EF1α) promoter is provided by the nucleotide sequence of SEQ ID NO: 4.
The nucleic acid constructs described herein comprise a reporter molecule operably linked (under control of) a minimal NFAT-responsive promoter. In some embodiments, the nucleic acid construct comprises a second reporter molecule operably linked (under control of) to a constitutively active promoter. Any suitable reporter molecule(s) may be used in the nucleic acid constructs described herein. Preferably a reporter molecule (a reporter protein) is readily detectable (directly or indirectly) upon expression. In some embodiments, the reporter molecule may be referred to as a screenable marker. Examples of reporter molecules include, without limitation, enzymes, such as β-glucuronidase, α-galactosidase, β-lactamase, and tyrosinase; luciferase; fluorescent markers/proteins. Fluorescent proteins include, but are not limited to, green fluorescent protein (GFP), red fluorescent protein (RFP), blue fluorescent protein (BFP), EBFP, cyan fluorescent protein, ECFP, EG fluorescent protein, yellow fluorescent protein, mWasabi, ZsGreen, yellow fluorescent protein (YFP), ZsYellow, mHoneydew, mApple, mRuby, mBanana, mOrange, mCherry, mCerulean, mTurquoise, mTangerine, mStrawberry, mGrape, mRaspberry, and mPlum. Selection of a suitable reporter molecule, such as a fluorescent protein, may depend on factors such as the means for detecting and/or quantifying the reporter molecule.
The nucleic acid constructs described herein comprise a reporter molecule operably linked (under control of) to a minimal NFAT-responsive promoter. In some embodiments, the nucleic acid construct comprises a second reporter molecule operably linked (under control of) to a constitutively active promoter. Any suitable reporter molecule(s) may be used in the nucleic acid constructs described herein. Preferably a reporter molecule (a reporter protein) is readily detectable (directly or indirectly) upon expression. In some embodiments, the reporter molecule may be referred to as a screenable marker. Examples of reporter molecules include, without limitation, enzymes, such as β-glucuronidase, α-galactosidase, β-lactamase, and tyrosinase; luciferase; fluorescent markers/proteins. Fluorescent proteins include, but are not limited to, green fluorescent protein (GFP), red fluorescent protein (RFP), blue fluorescent protein (BFP), EBFP, cyan fluorescent protein, ECFP, EG fluorescent protein, yellow fluorescent protein, mWasabi, ZsGreen, yellow fluorescent protein (YFP), ZsYellow, mHoneydew, mApple, mRuby, mBanana, mOrange, mCherry, mCerulean, mTurquoise, mTanerine, mStrawberry, mGrape, mRaspberry, and mPlum. Selection of a suitable reporter molecule, such as a fluorescent protein, may depend on factors such as the means for detecting and/or quantifying the reporter molecule.
In some embodiments, the reporter molecule is a fluorescent protein. In some embodiments, the reporter molecule operably linked to the NFAT-responsive promoter is a fluorescent protein. In some embodiments, fluorescent protein is mTurquoise or mOrange.
A nucleotide sequence encoding mTurquoise is provided by SEQ ID NO: 5.
A nucleotide sequence encoding mOrange is provided by SEQ ID NO: 6.
A chimeric antigen receptor (CAR) is an artificially constructed hybrid protein or polypeptide containing the antigen-binding domain of one or more antibodies (e.g., single chain variable fragment (scFv)) linked to T-cell signaling domains. Characteristics of CARs include their ability to redirect cell (e.g., T-cell) specificity and reactivity toward a selected target in a non-MHC-restricted manner, exploiting the antigen-binding properties of monoclonal antibodies. The non-MHC-restricted antigen recognition gives T cells expressing CARs the ability to recognize antigen independent of antigen processing, thus bypassing a major mechanism of tumor escape. Moreover, when expressed in T-cells, CARs advantageously do not dimerize with endogenous T cell receptor (TCR) alpha and beta chains. The phrases “antigen(ic) specificity” and “elicit antigen-specific response,” as used herein, means that the CAR can specifically bind to and immunologically recognize antigen, such that binding of the CAR to the antigen elicits an immune response.
There are three generations of CARs. “First generation” CARs are typically composed of an extracellular antigen-binding domain (e.g., a scFv), which is fused to a transmembrane domain, which is fused to cytoplasmic/intracellular signaling domain. First generation CARs can provide de novo antigen recognition and cause activation of both CD4+ and CD8+ T cells through their CD3ζ chain signaling domain in a single fusion molecule, independent of HLA-mediated antigen presentation. “Second generation” CARs add intracellular signaling domains from various co-stimulatory molecules (e.g., CD28, 4-1BB, ICOS, OX40, CD27, CD40/My88 and NKGD2) to the cytoplasmic tail of the CAR to provide additional signals to the T cell. Second generation CARs comprise those that provide both co-stimulation (e.g., CD28 or 4-1BB) and activation (CD3ζ). “Third generation” CARs comprise those that provide multiple co-stimulation (e.g., CD28 and 4-1BB) and activation (CD3ζ).
CAR constructs of embodiments of the invention (including functional portions and functional variants) can be of any length, i.e., can comprise any number of amino acids, provided that the CAR constructs (or functional portions or functional variants thereof) retain their biological activity, e.g., the ability to specifically bind to antigen, detect diseased cells in a mammal, or treat or prevent disease in a mammal, etc. For example, the CAR can be about 50 to about 5000 amino acids long, such as 50, 70, 75, 100, 125, 150, 175, 200, 300, 400, 500, 600, 700, 800, 900, 1000 or more amino acids in length.
In some embodiments, CAR constructs (including functional portions and functional variants of the invention) can comprise synthetic amino acids in place of one or more naturally-occurring amino acids. Such synthetic amino acids are known in the art, and include, for example, aminocyclohexane carboxylic acid, norleucine, a-amino n-decanoic acid, homoserine, S-acetylaminomethyl-cysteine, trans-3- and trans-4-hydroxyproline, 4-aminophenylalanine, 4-nitrophenylalanine, 4-chlorophenylalanine, 4-carboxyphenylalanine, b-phenylserine b-hydroxyphenylalanine, phenylglycine, a-naphthylalanine, cyclohexylalanine, cyclohexylglycine, indoline-2-carboxylic acid, 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid, aminomalonic acid, aminomalonic acid monoamide, N′-benzyl-N′-methyl-lysine, N′,N′-dibenzyl-lysine, 6-hydroxylysine, ornithine, a-aminocyclopentane carboxylic acid, a-aminocyclohexane carboxylic acid, a-aminocycloheptane carboxylic acid, a-(2-amino-2-norbornane)-carboxylic acid, a,g-diaminobutyric acid, a,b-diaminopropionic acid, homophenylalanine, and a-tert-butylglycine.
In some embodiments, CAR constructs (including functional portions and functional variants) can be glycosylated, amidated, carboxylated, phosphorylated, esterified, N-acylated, cyclized via, e.g., a disulfide bridge, or converted into an acid addition salt and/or optionally dimerized or polymerized, or conjugated.
In some embodiments, CAR constructs (including functional portions and functional variants thereof) can be obtained by methods known in the art. In some embodiments, CAR constructs may be made by any suitable method of making polypeptides or proteins, including de novo synthesis. CAR constructs can be recombinantly produced using the nucleic acids described herein using standard recombinant methods. See, for instance, Green et al., Molecular Cloning: A Laboratory Manual, 4th ed., Cold Spring Harbor Press, Cold Spring Harbor, NY 2012. Further, portions of some of the CAR constructs of the invention (including functional portions and functional variants thereof) can be isolated and/or purified from a source, such as a plant, a bacterium, an insect, a mammal, e.g., a rat, a human, etc. Methods of isolation and purification are well known in the art. Alternatively, the CAR constructs described herein (including functional portions and functional variants thereof) can be commercially synthesized by companies, such as Synpep (Dublin, CA). Peptide Technologies Corp. (Gaithersburg, MD), and Multiple Peptide Systems (San Diego, CA). In this respect, the inventive CAR constructs can be synthetic, recombinant, isolated, and/or purified.
Further provided by an embodiment of the invention is a nucleic acid comprising a nucleotide sequence encoding any of the CAR constructs described herein (including functional portions and functional variants thereof). The nucleic acids of the invention may comprise a nucleotide sequence encoding any of the leader sequences, antigen binding domains, transmembrane domains, linkers, and/or intracellular T cell signaling domains described herein.
In one embodiment, the CAR of the invention comprises an antigen-binding domain that binds to an antigen (e.g., a cancer antigen, a tumor antigen, a lineage-specific cell surface antigen) on a target cell. As will be appreciated by one of skill in the art, the CARs described herein, and antigen binding domains thereof, may be used with any antigen present on the surface of a cell known in the art. In some embodiments, the antigen is associated with a cancer, malignancy, or pre-malignancy. In some embodiments, the antigen is a lineage-specific cell-surface antigen. As used herein, the terms “lineage-specific cell-surface antigen” and “cell-surface lineage-specific antigen” may be used interchangeably and refer to any antigen that is sufficiently present on the surface of a cell and is associated with one or more populations of cell lineage(s). For example, the antigen may be present on one or more populations of cell lineage(s) and absent (or at reduced levels) on the cell-surface of other cell populations.
In general, lineage-specific cell-surface antigens can be classified based on a number of factors such as whether the antigen and/or the populations of cells that present the antigen are required for survival and/or development of the host organism.
In some embodiments, the cell-surface lineage-specific antigen may be a cancer antigen, for example a cell-surface lineage-specific antigen that is differentially present on cancer cells. In some embodiments, the cancer antigen is an antigen that is specific to a tissue or cell lineage. Examples of cell-surface lineage-specific antigen that are associated with a specific type of cancer include, without limitation, CD20, CD22 (Non-Hodgkin's) lymphoma, B-cell lymphoma, chronic lymphocytic leukemia (CLL)), CD52 (B-cell CLL), CD33 (Acute myelogenous leukemia (AML)), CD10 (gp100) (Common (pre-B) acute lymphocytic leukemia and malignant melanoma), CD3/T-cell receptor (TCR) (T-cell lymphoma and leukemia), CD79/B-cell receptor (BCR) (B-cell lymphoma and leukemia), CD26 (epithelial and lymphoid malignancies), RCAS1 (gynecological carcinomas, biliary adenocarcinomas and ductal adenocarcinomas of the pancreas) as well as prostate specific membrane antigen. In some embodiments, the cell-surface antigen CD33 and is associated with AML cells.
Any antibody or antigen-binding fragment thereof can be used for constructing a CAR as described herein. The antigen-binding domain may comprise any antigen-binding portion of an antibody. The antigen-binding portion can be any portion that has at least one antigen binding site, such as Fab, F(ab′)2, dsFv, scFv, diabodies, and triabodies. In some embodiments, the antigen-binding portion is a single-chain variable region fragment (scFv) antigen-binding fragment. An scFv is a truncated Fab fragment including the variable (V) domain of an antibody heavy chain linked to a V domain of a light antibody chain via a synthetic peptide linker, which can be generated using routine recombinant DNA technology techniques. Similarly, disulfide-stabilized variable region fragments (dsFv) can be prepared by recombinant DNA technology.
The antigen-binding domain can include, but is not limited to, a monoclonal antibody, a polyclonal antibody, a synthetic antibody, a human antibody, a humanized antibody, a non-human antibody, and any fragment thereof. Thus, in some embodiments, the antigen binding domain portion comprises a mammalian antibody or a fragment thereof.
In some instances, the antigen-binding domain is derived from the same species in which the CAR will ultimately be used herein. For example, for use in humans, the antigen binding domain of the CAR comprises a human antibody, a humanized antibody, or a fragment thereof. Human antibodies can be made by a variety of methods known in the art including phage display methods using antibody libraries derived from human immunoglobulin sequences, including improvements to these techniques. See, also, U.S. Pat. Nos. 4,444,887 and 4,716,111; and PCT Publication Nos WO 98/46645, WO 98/50433, WO 98/24893, WO 98/16654, WO 96/34096, WO 96/33735, and WO 91/10741; each of which is incorporated herein by reference in its entirety.
For example, antibodies specific to a lineage-specific antigen of interest can be made by the conventional hybridoma technology. The lineage-specific antigen, which may be coupled to a carrier protein such as KLH, can be used to immunize a host animal for generating antibodies binding to that complex. The route and schedule of immunization of the host animal are generally in keeping with established, and conventional techniques for antibody stimulation and production, as further described herein. General techniques for production of mouse, humanized, and human antibodies are known in the art and are described herein. It is contemplated that any mammalian subject including humans or antibody producing cells therefrom can be manipulated to serve as the basis for production of mammalian, including human hybridoma cell lines. Typically, the host animal is inoculated intraperitoneally, intramuscularly, orally, subcutaneously, intraplantar, and/or intradermally with an amount of immunogen including, as described herein.
Hybridomas can be prepared from the lymphocytes and immortalized myeloma cells using the general somatic cell hybridization technique of Kohler. B. and Milstein. C. (1975) Nature 256: 495-497 or as modified by Buck, D. W., et al., In Vitro, 18: 377-381 (1982). Available myeloma lines, including but not limited to X63-Ag8.653 and those from the Salk Institute, Cell Distribution Center, San Diego, Calif., USA, may be used in the hybridization. Generally, the technique involves fusing myeloma cells and lymphoid cells using a fusogen such as polyethylene glycol, or by electrical means well known to those skilled in the art. After the fusion, the cells are separated from the fusion medium and grown in a selective growth medium, such as hypoxanthine-aminopterin-thymidine (HAT) medium, to eliminate unhybridized parent cells. Any of the media described herein, supplemented with or without serum, can be used for culturing hybridomas that secrete monoclonal antibodies. As another alternative to the cell fusion technique, EBV immortalized B cells may be used to produce the TCR-like monoclonal antibodies described herein. The hybridomas are expanded and subcloned, if desired, and supernatants are assayed for anti-immunogen activity by conventional immunoassay procedures (e.g., radioimmunoassay, enzyme immunoassay, or fluorescence immunoassay).
Hybridomas that may be used as a source of antibodies encompass all derivatives, progeny cells of the parent hybridomas that produce monoclonal antibodies capable of binding to a lineage-specific antigen. Hybridomas that produce such antibodies may be grown in vitro or in vivo using known procedures. The monoclonal antibodies may be isolated from the culture media or body fluids, by conventional immunoglobulin purification procedures such as ammonium sulfate precipitation, gel electrophoresis, dialysis, chromatography, and ultrafiltration, if desired. Undesired activity if present, can be removed, for example, by running the preparation over adsorbents made of the immunogen attached to a solid phase and eluting or releasing the desired antibodies off the immunogen. Immunization of a host animal with a target antigen or a fragment containing the target amino acid sequence conjugated to a protein that is immunogenic in the species to be immunized, e.g., keyhole limpet hemocyanin, serum albumin, bovine thyroglobulin, or soybean trypsin inhibitor using a bifunctional or derivatizing agent, for example maleimidobenzoyl sulfosuccinimide ester (conjugation through cysteine residues), N-hydroxysuccinimide (through lysine residues), glutaraldehyde, succinic anhydride, SOCl, or R1N═C═NR, where R and R1 are different alkyl groups, can yield a population of antibodies (e.g., monoclonal antibodies).
If desired, an antibody of interest (e.g., produced by a hybridoma) may be sequenced and the polynucleotide sequence may then be cloned into a vector for expression or propagation. The sequence encoding the antibody of interest may be maintained in vector in a host cell and the host cell can then be expanded and frozen for future use. In an alternative, the polynucleotide sequence may be used for genetic manipulation to “humanize” the antibody or to improve the affinity (affinity maturation), or other characteristics of the antibody. For example, the constant region may be engineered to more resemble human constant regions to avoid immune response if the antibody is used in clinical trials and treatments in humans. It may be desirable to genetically manipulate the antibody sequence to obtain greater affinity to the lineage-specific antigen. It will be apparent to one of skill in the art that one or more polynucleotide changes can be made to the antibody and still maintain its binding specificity to the target antigen.
In other embodiments, fully human antibodies can be obtained by using commercially available mice that have been engineered to express specific human immunoglobulin proteins. Transgenic animals that are designed to produce a more desirable (e.g., fully human antibodies) or more robust immune response may also be used for generation of humanized or human antibodies. Examples of such technology are Xenomouse® from Amgen, Inc. (Fremont, Calif.) and HuMAb-Mouse® and TC Mouse™ from Medarex, Inc. (Princeton, N.J.). In another alternative, antibodies may be made recombinantly by phage display or yeast technology. See, for example, U.S. Pat. Nos. 5,565,332; 5,580,717; 5,733,743; and 6,265,150; and Winter et al., (1994) Annu. Rev. Immunol. 12:433-455. Alternatively, the phage display technology (McCafferty et al., (1990) Nature 348:552-553) can be used to produce human antibodies and antibody and antibody fragments in vitro, from immunoglobulin variable (V) domain gene repertoires from unimmunized donors.
Antigen-binding fragments of an intact antibody (full-length antibody) can be prepared via routine methods. For example, F(ab′)2 fragments can be produced by pepsin digestion of an antibody molecule, and Fab fragments that can be generated by reducing the disulfide bridges of F(ab′)2 fragments.
Genetically engineered antibodies, and bi-specific antibodies, can be produced via, e.g., conventional recombinant technology. In one example, DNA encoding a monoclonal antibodies specific to a target antigen can be readily isolated and sequenced using conventional procedures (e.g., by using oligonucleotide probes that are capable of binding specifically to genes encoding the heavy and light chains of the monoclonal antibodies). The hybridoma cells serve as a preferred source of such DNA. Once isolated, the DNA may be placed into one or more expression vectors, which are then transfected into host cells such as E. coli cells, simian COS cells, Chinese hamster ovary (CHO) cells, or myeloma cells that do not otherwise produce immunoglobulin protein, to obtain the synthesis of monoclonal antibodies in the recombinant host cells. See, e.g., PCT Publication No. WO 87/04462. The DNA can then be modified, for example, by substituting the coding sequence for human heavy and light chain constant domains in place of the homologous murine sequences, Morrison et al., (1984) Proc. Nat. Acad. Sci. 81:6851, or by covalently joining to the immunoglobulin coding sequence all or part of the coding sequence for a non-immunoglobulin polypeptide. In that manner, genetically engineered antibodies, such as “chimeric” or “hybrid” antibodies; can be prepared that have the binding specificity of a target antigen.
Techniques developed for the production of “chimeric antibodies” are well known in the art. See, e.g., Morrison et al. (1984) Proc. Natl. Acad. Sci. USA 81, 6851; Neuberger et al. (1984) Nature 312, 604; and Takeda et al. (1984) Nature 314:452.
Methods for constructing humanized antibodies are also well known in the art. See, e.g., Queen et al., Proc. Natl. Acad. Sci. USA, 86:10029-10033 (1989). In one example, variable regions of VH and VL of a parent non-human antibody are subjected to three-dimensional molecular modeling analysis following methods known in the art. Next, framework amino acid residues predicted to be important for the formation of the correct CDR structures are identified using the same molecular modeling analysis. In parallel, human VH and VL chains having amino acid sequences that are homologous to those of the parent non-human antibody are identified from any antibody gene database using the parent VH and VL sequences as search queries. Human VH and VL acceptor genes are then selected.
The CDR regions within the selected human acceptor genes can be replaced with the CDR regions from the parent non-human antibody or functional variants thereof. When necessary, residues within the framework regions of the parent chain that are predicted to be important in interacting with the CDR regions (see above description) can be used to substitute for the corresponding residues in the human acceptor genes.
A single-chain antibody can be prepared via recombinant technology by linking a nucleotide sequence coding for a heavy chain variable region and a nucleotide sequence coding for a light chain variable region. Preferably, a flexible linker is incorporated between the two variable regions. Alternatively, techniques described for the production of single chain antibodies (U.S. Pat. Nos. 4,946,778 and 4,704,692) can be adapted to produce a phage or yeast scFv library and scFv clones specific to a lineage-specific antigen can be identified from the library following routine procedures. Positive clones can be subjected to further screening to identify those that bind lineage-specific antigens.
In some aspects of the invention, the antigen-binding domain is operably linked to another domain of the CAR, such as a linker region, hinge region, transmembrane domain, or the intracellular domain, for expression in the cell. In some embodiments, a nucleic acid encoding the antigen-binding domain is operably linked to a nucleic acid encoding a transmembrane domain and a nucleic acid encoding an intracellular domain.
In an embodiment of the invention, the light chain variable region and the heavy chain variable region of the antigen-binding domain can be joined to each other by a linker. The linker may comprise any suitable amino acid sequence. In some embodiments, the linker is a Gly/Ser linker from about 1 to about 100, from about 3 to about 20, from about 5 to about 30, from about 5 to about 18, or from about 3 to about 8 amino acids in length and consists of glycine and/or serine residues in sequence. Accordingly, the Gly/Ser linker may consist of glycine and/or serine residues. Preferably, the Gly/Ser linker comprises the amino acid sequence of GGGGS (SEQ ID NO: 7), and multiple sequences comprising SEQ ID NO: 7 may be present within the linker. Any linker sequence may be used as a spacer between the antigen-binding domain and the transmembrane domain.
In some embodiments, the antigen-binding domain comprises one or more leader sequences (signal peptides). In some embodiments, the leader sequence may be positioned at the amino terminus of the CAR within the CAR construct. The leader sequence may comprise any suitable leader sequence, e.g., any CAR described herein may comprise any leader sequence as described herein. In some embodiments, while the leader sequence may facilitate expression of the released CARs on the surface of the cell, the presence of the leader sequence in an expressed CAR is not necessary in order for the CAR to function. In some embodiments, upon expression of the CAR on the cell surface, the leader sequence may be cleaved off. Accordingly, in some embodiments, the released CARs lack a leader sequence. In some embodiments, the CARs within the CAR construct lack a leader sequence.
By way of an example, in some embodiments, the lineage-specific antigen of interest is CD33 and the antigen-binding domain of a CAR specifically binds CD33, for example, human CD33. In some embodiments, a CAR comprises an anti-CD33 antigen-binding domain comprising, consisting of, or consisting essentially of, an antigen-binding fragment such as a single chain variable fragment (scFv) of the antigen-binding domain.
In some embodiments, the CAR comprises an anti-CD33 antigen binding domain, for example of an anti-CD33 antibody, such as any anti-CD33 antibody known in the art. In some embodiments, an anti-CD33 antigen-binding domain is a monoclonal antibody, or antigen-binding fragment thereof. In some embodiments, an anti-CD33 antigen-binding domain is a humanized antibody, or antigen-binding fragment thereof.
In some embodiments, a CAR can also comprise a hinge/spacer region that links the extracellular antigen-binding domain to the transmembrane domain. The hinge/spacer region can be flexible enough to allow the antigen-binding domain to orient in different directions to facilitate antigen recognition.
In some embodiments, the CAR construct comprises a hinge domain. In some embodiments, the hinge domain is a CD8 (e.g., CD8a) hinge domain. In some embodiments, the CD8 hinge domain is human. In some embodiments, the CD8 hinge domain comprises, consists of, or consists essentially of SEQ ID NO: 8. In some embodiments, the hinge domain is a CD28 hinge domain. In some embodiments, the CD28 hinge domain is human (e.g., obtained or derived from a human protein). In some embodiments, the CD28 hinge domain comprises, consists of, or consists essentially of SEQ ID NO: 9. In some embodiments, the hinge domain is a portion of the hinge domain of CD8a, e.g., a fragment containing at least 15 (e.g., 20, 25, 30, 35, or 40) consecutive amino acids of the hinge domain of CD8a, or CD28, as shown respectively below.
Hinge domains of antibodies, such as an IgG, IgA, IgM, IgE, or IgD antibody, are also compatible for use in the chimeric receptors described herein. In some embodiments, the hinge domain is the hinge domain that joins the constant domains CH1 and CH2 of an antibody. In some embodiments, the hinge domain is of an antibody and comprises the hinge domain of the antibody and one or more constant regions of the antibody. In some embodiments, the hinge domain comprises the hinge domain of an antibody and the CH3 constant region of the antibody. In some embodiments, the hinge domain comprises the hinge domain of an antibody and the CH2 and CH3 constant regions of the antibody. In some embodiments, the antibody is an IgG, IgA, IgM, IgE, or IgD antibody. In some embodiments, the antibody is an IgG antibody. In some embodiments, the antibody is an IgG1, IgG2, IgG3, or IgG4 antibody. In some embodiments, the hinge region comprises the hinge region and the CH2 and CH3 constant regions of an IgG1 antibody. In some embodiments, the hinge region comprises the hinge region and the CH3 constant region of an IgG1 antibody. In some embodiments, the hinge domain is an IgG4 hinge domain.
Also within the scope of the present disclosure are chimeric receptors comprising a hinge domain that is a non-naturally occurring peptide. In some embodiments, the hinge domain between the C-terminus of the extracellular ligand-binding domain of an Fc receptor and the N-terminus of the transmembrane domain is a peptide linker, such as a (GlyxSer)n linker, wherein x and n, independently can be an integer between 3 and 12, including 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or more.
Additional peptide linkers that may be used in a hinge domain of the chimeric receptors described herein are known in the art. See, e.g., Wriggers et al. Current Trends in Peptide Science (2005) 80(6): 736-74 and PCT Publication WO 2012/088461.
In certain embodiments, the hinge/spacer region of a presently disclosed CAR comprises a native or modified hinge region of a CD28 polypeptide as described herein. In some embodiments, the hinge/spacer region of a presently disclosed CAR construct comprises a native or modified hinge region of a CD8a polypeptide as described herein. In some embodiments, the hinge/spacer region of a presently disclosed CAR construct comprises a native or modified hinge region of a IgG4 polypeptide as described herein.
With respect to the transmembrane domain, a CAR can be designed to comprise a transmembrane domain that connects the antigen-binding domain of the CAR to the intracellular domain. In some embodiments, the transmembrane domain is naturally associated with one or more of the domains in the CAR. In some instances, the transmembrane domain can be selected or modified by amino acid substitution to avoid binding of such domains to the transmembrane domains of the same or different surface membrane proteins to minimize interactions with other members of the receptor complex.
The transmembrane domain may be derived either from a natural or from a synthetic source. Where the source is natural, the domain may be derived from any membrane-bound or transmembrane protein. Transmembrane regions of particular use in this invention may be derived from (i.e. comprise at least the transmembrane region(s) of the alpha, beta or zeta chain of the T-cell receptor, CD28, CD3 epsilon, CD45, CD4, CD5, CD8, CD8a, CD9, CD 16, CD22, CD33, CD37, CD64, CD80, CD86, CD134, CD137, CD154, Toll-like receptor 1 (TLR1), TLR2, TLR3, TLR4, TLR5, TLR6, TLR7, TLR8, and TLR9.
In some embodiments, the transmembrane domain may be synthetic, in which case it will comprise predominantly hydrophobic residues such as leucine and valine. Preferably a triplet of phenylalanine, tryptophan and valine will be found at each end of a synthetic transmembrane domain.
In some embodiments, the transmembrane domain is a CD8 (e.g., CD8a) transmembrane domain. In some embodiments, the CD8 transmembrane domain is human (e.g., obtained/derived from a human protein). In some embodiments, the CD8 transmembrane domain comprises, consists of, or consists essentially of SEQ ID NO: 10: IYIWAPLAGTCGVLLLSLVITLYC [SEQ ID NO: 10].
In some embodiments, the CD28 transmembrane domain is human. In some embodiments, the CD28 transmembrane domain comprises, consists of, or consists essentially of SEQ ID NO: 11:
In some embodiments, a CAR construct comprises an intracellular signaling domain. The intracellular signaling domain of the CAR, is responsible for activation of the cell in which the CAR is expressed. In one embodiment, the intracellular signaling domain of the CAR construct described herein includes a domain responsible for signal activation and/or transduction.
Examples of an intracellular signaling domain for use in the CAR constructs described herein include, but are not limited to, the cytoplasmic portion of a surface receptor, co-stimulatory molecule, and any molecule that acts in concert to initiate signal transduction in an immune cell (e.g., a T lymphocyte), as well as any derivative or variant of these elements and any synthetic sequence that has the same functional capability.
Examples of the intracellular domains include a fragment or domain from one or more molecules or receptors including, but are not limited to, TCR, CD3 zeta (CD3ζ), CD3 gamma, CD3 delta, CD3 epsilon, CD86, common FcR gamma, FcR beta (Fc Epsilon Rib), CD79a, CD79b, Fcgamma RIIa, DAP10, DAP 12, T cell receptor (TCR), CD27, CD28, 4-1BB (CD137), OX40, CD30, CD40, PD-1, ICOS, lymphocyte function-associated antigen-1 (LFA-1), CD2, CD7, LIGHT, NKG2C, B7-H3, a ligand that specifically binds with CD83, CDS, ICAM-1, GITR, BAFFR, HVEM (LIGHTR), SLAMF7, NKp80 (KLRF1), CD127, CD160, CD19, CD4, CD8alpha, CD8beta, IL2R beta, IL2R gamma, IL7R alpha, ITGA4, VLA1, CD49a, ITGA4, IA4, CD49D, ITGA6, VLA-6, CD49f, ITGAD, CD11d, ITGAE, CD103, ITGAL, CD11a, LFA-1, ITGAM, CD11b, ITGAX, CD11c, ITGB1, CD29, ITGB2, CD18, LFA-1, ITGB7, TNFR2, TRANCE/RANKL, DNAM1 (CD226), SLAMF4 (CD244, 2B4), CD84, CD96 (Tactile), CEACAM1, CRTAM, Ly9 (CD229), CD160 (BY55), PSGL1, CD100 (SEMA4D), CD69, SLAMF6 (NTB-A, Ly108), SLAM (SLAMF1, CD150, IPO-3), BLAME (SLAMF8), SELPLG (CD 162), LTBR, LAT, GADS, SLP-76, PAG/Cbp, NKp44, NKp30, NKp46, NKG2D, Toll-like receptor 1 (TLR1), TLR2, TLR3, TLR4, TLR5, TLR6, TLR7, TLR8, TLR9, other co-stimulatory molecules described herein, any derivative, variant, or fragment thereof, any synthetic sequence of a co-stimulatory molecule that has the same functional capability, and any combination thereof.
Any cytoplasmic signaling domain can be used in the chimeric receptors described herein. In general, a cytoplasmic signaling domain relays a signal, such as interaction of an extracellular ligand-binding domain with its ligand, to stimulate a cellular response, such as inducing an effector function of the cell (e.g., cytotoxicity).
As will be evident to one of ordinary skill in the art, a factor involved in T cell activation is the phosphorylation of immunoreceptor tyrosine-based activation motif (ITAM) of a cytoplasmic signaling domain. Any ITAM-containing domain known in the art may be used to construct the chimeric receptors described herein, and included as part of the cytoplasmic signaling domain. In general, an ITAM motif may comprise two repeats of the amino acid sequence YxxL/I (SEQ ID NO: 19) separated by 6-8 amino acids, wherein each x is independently any amino acid, producing the conserved motif YxxL/Ix(6-8)YxxL/I (SEQ ID NO: 20). In some embodiments, the cytoplasmic signaling domain is from CD3ζ.
CD3ζ associates with TCRs to produce a signal and contains immunoreceptor tyrosine-based activation motifs (ITAMs). In some embodiments, a CD3ζ intracellular T cell signaling sequence is human. In some embodiments, an intracellular T cell signaling domain comprises a CD3ζ that contains on or more mutated and/or deleted ITAMs. In some embodiments, a CD3ζ intracellular T cell signaling sequence comprises, consists of, or consists essentially of the amino acid sequence of SEQ ID NO: 12, or a sequence that is at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical the amino acid sequence of SEQ ID NO: 12:
In certain non-limiting embodiments, an intracellular signaling domain of the CAR further comprises at least one co-stimulatory signaling molecule. In certain embodiments, the co-stimulatory signaling region comprises at least one co-stimulatory molecule, which can provide optimal lymphocyte activation. In general, many immune cells require co-stimulation, in addition to stimulation of an antigen-specific signal, to promote cell proliferation, differentiation and survival, and to activate effector functions of the cell. Activation of a co-stimulatory signaling domain in a host cell (e.g., an immune cell) may induce the cell to increase or decrease the production and secretion of cytokines, phagocytic properties, proliferation, differentiation, survival, and/or cytotoxicity. The co-stimulatory signaling domain of any co-stimulatory protein may be compatible for use in the chimeric receptors described herein. The type(s) of co-stimulatory signaling domain is selected based on factors such as the type of the immune cells in which the chimeric receptors would be expressed (e.g., primary T cells, T cell lines, NK cell lines) and the desired immune effector function (e.g., cytotoxicity).
Examples of such co-stimulatory domain include, but are not limited to 4-1BB, CD28, ICOS, TLR1, TLR2, TLR3, TLR4, TLR5, TLR6, TLR7, TLR8, TLR9, TLR10, TLR11, CD116 receptor beta chain, CSF1-R, LRP1/CD91, SR-A1, SR-A2, MARCO, SR-CL1, SR-CL2, SR-C, SR-E, CR1, CR3, CR4, dectin 1, DEC-205, DC-SIGN, CD14, CD36, LOX-1, CD11b, together with any of the signaling domains listed in the above paragraph in any combination. In another embodiment, the intracellular domain of the CAR includes any portion of one or more co-stimulatory molecules, such as at least one signaling domain from CD3, Fc epsilon RI gamma chain, any derivative or variant thereof, any synthetic sequence thereof that has the same functional capability, and any combination thereof.
In some embodiments one or more co-stimulatory domains are included in a CAR construct with a CD3ζ intracellular T cell signaling sequence. In some embodiments, the one or more co-stimulatory domains are selected from CD137 (4-1BB) and CD28, or a combination thereof.
4-1BB, also known as CD137, transmits a potent costimulatory signal to T cells, promoting differentiation and enhancing long-term survival of T lymphocytes. In some embodiments, a 4-1BB intracellular T cell signaling sequence is human (e.g., obtained/derived from a human protein). In some embodiments, the 4-1BB intracellular T cell signaling sequence comprises, consists of, or consists essentially of the amino acid sequence of SEQ ID NO: 13:
Between the antigen-binding domain and the transmembrane domain of the CAR, or between the intracellular domain and the transmembrane domain of the CAR, a spacer domain may be incorporated. As used herein, the term “spacer domain” generally means any oligo- or polypeptide that functions to link the transmembrane domain to, either the antigen binding domain or, the intracellular domain in the polypeptide chain. In one embodiment, the spacer domain may comprise up to 300 amino acids, preferably 10 to 100 amino acids and most preferably 25 to 50 amino acids. In another embodiment, a short oligo- or polypeptide linker, preferably between 2 and 10 amino acids in length may form the linkage between the transmembrane domain and the intracellular domain of the CAR. An example of a linker includes a glycine-serine doublet.
The CARs described herein may be prepared in constructs with, e.g., self-cleaving peptides, such that the CAR constructs containing anti-CD33 CAR components are bicistronic, tricistronic, etc.
Provided herein are nucleic acids, including nucleic acids encoding an IL-2 reporter system comprising an NFAT-responsive promoter operably linked to a reporter molecule. Also provided herein are nucleic acids encoding CAR constructs described herein. In some embodiments, any of the nucleic acids described herein can be incorporated into a vector (e.g., a recombinant expression vector). For purposes herein, the term “recombinant expression vector” means a genetically-modified oligonucleotide or polynucleotide construct that permits the expression of an mRNA, protein, polypeptide, or peptide by a host cell, when the construct comprises a nucleotide sequence encoding the mRNA, protein, polypeptide, or peptide, and the vector is contacted with the cell under conditions sufficient to have the mRNA, protein, polypeptide, or peptide expressed within the cell.
In some embodiments, the vectors are not naturally-occurring as a whole. However, parts of the vectors can be naturally-occurring. The inventive recombinant expression vectors can comprise any type of nucleotides, including, but not limited to DNA and RNA, which can be single-stranded or double-stranded, synthesized or obtained in part from natural sources, and which can contain natural, non-natural or altered nucleotides. The recombinant expression vectors can comprise naturally-occurring or non-naturally-occurring internucleotide linkages, or both types of linkages. In some embodiments, a non-naturally occurring or altered nucleotides or internucleotide linkages do not hinder the transcription or replication of the vector.
In some embodiments, a vector of the invention can be any suitable recombinant expression vector, and can be used to transform or transfect any suitable host cell. Suitable vectors include those designed for propagation and expansion or for expression or both, such as plasmids and viruses. A vector can be selected from the group consisting of the pUC series (Fermentas Life Sciences, Glen Burnie, MD), the pBluescript series (Stratagene, LaJolla, CA), the pET series (Novagen, Madison, WI), the pGEX series (Pharmacia Biotech, Uppsala, Sweden), and the pEX series (Clontech, Palo Alto, CA). Bacteriophage vectors, such as LGTlO, λGT11, LZapII (Stratagene), λEMBT4, and λNMI149, also can be used. Examples of plant expression vectors include pBIO1, pBI101.2, pBI101.3, pBH21 and pBIN19 (Clontech). Examples of animal expression vectors include pEUK-CI, pMAM, and pMAMneo (Clontech). The recombinant expression vector may be a viral vector, e.g., a retroviral vector or a lentiviral vector.
In an embodiment, recombinant expression vectors of the invention can be prepared using standard recombinant DNA techniques described in, for example, Green et al., supra. Constructs of expression vectors, which are circular or linear, can be prepared to contain a replication system functional in a prokaryotic or eukaryotic host cell. Replication systems can be derived, e.g., from ColE1, 2μ plasmid, λ, SV40, bovine papilloma virus, and the like.
A recombinant expression vector may comprise regulatory sequences, such as transcription and translation initiation and termination codons, which are specific to the type of host cell (e.g., bacterium, fungus, plant, or animal) into which the vector is to be introduced, as appropriate, and taking into consideration whether the vector is DNA- or RNA-based. A recombinant expression vector may also comprise restriction sites to facilitate cloning.
A recombinant expression vector can include one or more marker genes, which allow for selection of transformed or transfected host cells. Marker genes include biocide resistance, e.g., resistance to antibiotics, heavy metals, etc., complementation in an auxotrophic host to provide prototrophy, and the like. Suitable marker genes for the inventive expression vectors include, for instance, neomycin/G418 resistance genes, hygromycin resistance genes, histidinol resistance genes, tetracycline resistance genes, and ampicillin resistance genes.
Further, the recombinant expression vectors can be made to include a suicide gene. As used herein, the term “suicide gene” refers to a gene that causes the cell expressing the suicide gene to die. A suicide gene can be a gene that confers sensitivity to an agent, e.g., a drug, upon the cell in which the gene is expressed, and causes the cell to die when the cell is contacted with or exposed to the agent. Suicide genes are known in the art and include, for example, the Herpes Simplex Virus (HSV) thymidine kinase (TK) gene, cytosine deaminase, purine nucleoside phosphorylase, and nitroreductase.
In some embodiments, a recombinant expression vector can comprise a native or nonnative promoter operably linked to the nucleotide sequence encoding the CAR construct (including functional portions and functional variants thereof), or to the nucleotide sequence which is complementary to or which hybridizes to the nucleotide sequence encoding the CAR construct. The selection of promoters, e.g., strong, weak, inducible, tissue-specific and developmental-specific, is within the ordinary skill of the artisan. Similarly, the combining of a nucleotide sequence with a promoter is also within the skill of the artisan. The promoter can be a non-viral promoter or a viral promoter, e.g., a cytomegalovirus (CMV) promoter, a SFFV promoter, an EF1α promoter, an SV40 promoter, an RSV promoter, or a promoter found in the long-terminal repeat of the murine stem cell virus.
The inventive recombinant expression vectors can be designed for either transient expression, for stable expression, or for both. Also, the recombinant expression vectors can be made for constitutive expression or for inducible expression.
Included in the scope of the invention are conjugates, e.g., bioconjugates, comprising any of the inventive CAR constructs (including any of the functional portions or variants thereof), nucleic acids, recombinant expression vectors, host cells, or populations of host cells. Conjugates, as well as methods of synthesizing conjugates in general, are known in the art.
In one aspect, the invention includes a method for modifying a cell comprising introducing into the cell a nucleic acid encoding an IL-2 reporter system comprising a NFAT-responsive promoter operably linked to a reporter molecule, or a vector encoding such a nucleic acid. In some embodiments, the method involves introducing the nucleic acid encoding an IL-2 reporter system into the cell to produce a reporter cell or reporter cell line. In some embodiments, introducing the nucleic acid sequence comprises electroporating a mRNA encoding the IL-2 reporter system to produce a reporter cell or reporter cell line.
In some aspects, the present disclosure includes a method for modifying a cell comprising introducing a chimeric antigen receptor (CAR) into an immune cell (e.g., a T lymphocyte), wherein the CAR comprises an antigen binding domain, a transmembrane domain and an intracellular domain of a co-stimulatory molecule, and wherein the immune cell expresses the CAR and possesses targeted effector activity. In one embodiment, introducing the CAR into the cell comprises introducing a nucleic acid sequence encoding the CAR. In another embodiment, introducing the nucleic acid sequence comprises electroporating a mRNA encoding the CAR. In some embodiments, the methods involve introducing a nucleic acid sequence encoding the CAR to a cell that comprises any of the IL-2 reporter systems described herein.
For purposes herein, any of the constructs described herein may be introduced into a cell, such as an immune cell, e.g., T cell (i.e., T lymphocyte) or NK cell. A T cell can be any T cell, such as a cultured T cell, e.g., a primary T cell, or a T cell from a cultured T cell line, e.g., Jurkat, SupTl, etc., or a T cell obtained from a mammal. If obtained from a mammal, a T cell can be obtained from numerous sources, including but not limited to blood, bone marrow, lymph node, the thymus, or other tissues or fluids. T cells can also be enriched for or purified. A T cell may be a human T cell. A T cell may be a T cell isolated from a human. A T cell can be any type of T cell and can be of any developmental stage, including but not limited to, CD4+/CD8+ double positive T cells, CD4+ helper T cells, e.g., Th1 and Th2 cells, CD8+ T cells (e.g., cytotoxic T cells), tumor infiltrating cells, memory T cells, naive T cells, and the like. A T cell may be a CD8+ T cell or a CD4+ T cell.
In some embodiments, a suitable cell or cell type for modification with the nucleic acids described herein are cells that are susceptible to T-cell activation. In some embodiments, T-cell activation is induced by PMA/Ionomycin.
Methods of introducing and expressing genes, such as the reporter systems and/or CARs described herein, into a cell are known in the art. In the context of an expression vector, the vector can be readily introduced into a host cell, e.g., mammalian, bacterial, yeast, or insect cell by any method in the art. For example, the expression vector can be transferred into a host cell by physical, chemical, or biological means.
Physical methods for introducing a polynucleotide into a host cell include calcium phosphate precipitation, lipofection, particle bombardment, microinjection, electroporation, and the like. Methods for producing cells comprising vectors and/or exogenous nucleic acids are well known in the art. See, for example, Sambrook et al., 2012, MOLECULAR CLONING: A LABORATORY MANUAL, volumes 1-4, Cold Spring Harbor Press, NY). Nucleic acids can be introduced into target cells using commercially available methods which include electroporation (Amaxa Nucleofector-II (Amaxa Biosystems, Cologne, Germany)), (ECM 830 (BTX) (Harvard Instruments, Boston, Mass.) or the Gene Pulser II (BioRad, Denver, Colo.), Multiporator (Eppendort, Hamburg Germany). Nucleic acids can also be introduced into cells using cationic liposome mediated transfection using lipofection, using polymer encapsulation, using peptide mediated transfection, or using biolistic particle delivery systems such as “gene guns” (see, for example, Nishikawa, et al. Hum Gene Ther., 12(8):861-70 (2001).
In one aspect, the RNA construct is delivered into the cells by electroporation. See, e.g., the formulations and methodology of electroporation of nucleic acid constructs into mammalian cells as taught in US 2004/0014645, US 2005/0052630A1, US 2005/0070841 A1, US 2004/0059285A1, US 2004/0092907A1. The various parameters including electric field strength required for electroporation of any known cell type are generally known in the relevant research literature as well as numerous patents and applications in the field. See e.g., U.S. Pat. Nos. 6,678,556, 7,171,264, and 7,173,116. Apparatus for therapeutic application of electroporation are available commercially, e.g., the MedPulser™ DNA Electroporation Therapy System (Inovio/Genetronics, San Diego, Calif), and are described in patents such as U.S. Pat. Nos. 6,567,694; 6,516,223, 5,993,434, 6,181,964, 6,241,701, and 6,233,482; electroporation may also be used for transfection of cells in vitro as described e.g. in US20070128708A1. Electroporation may also be utilized to deliver nucleic acids into cells in vitro. Accordingly, electroporation-mediated administration into cells of nucleic acids including expression constructs utilizing any of the many available devices and electroporation systems known to those of skill in the art presents an exciting new means for delivering an RNA of interest to a target cell.
Biological methods for introducing a polynucleotide of interest into a host cell include the use of DNA and RNA vectors. RNA vectors include vectors having a RNA promoter and/other relevant domains for production of a RNA transcript. Viral vectors, and especially retroviral vectors, have become the most widely used method for inserting genes into mammalian, e.g., human cells. Other viral vectors may be derived from lentivirus, poxviruses, herpes simplex virus, adenoviruses and adeno-associated viruses, and the like. See, for example, U.S. Pat. Nos. 5,350,674 and 5,585,362.
Chemical means for introducing a polynucleotide into a host cell include colloidal dispersion systems, such as macromolecule complexes, nanocapsules, microspheres, beads, and lipid-based systems including oil-in-water emulsions, micelles, mixed micelles, and liposomes. An exemplary colloidal system for use as a delivery vehicle in vitro and in vivo is a liposome (e.g., an artificial membrane vesicle).
In the case where a non-viral delivery system is utilized, an exemplary delivery vehicle is a liposome. The use of lipid formulations is contemplated for the introduction of the nucleic acids into a host cell (in vitro, ex vivo or in vivo). In another aspect, the nucleic acid may be associated with a lipid. The nucleic acid associated with a lipid may be encapsulated in the aqueous interior of a liposome, interspersed within the lipid bilayer of a liposome, attached to a liposome via a linking molecule that is associated with both the liposome and the oligonucleotide, entrapped in a liposome, complexed with a liposome, dispersed in a solution containing a lipid, mixed with a lipid, combined with a lipid, contained as a suspension in a lipid, contained or complexed with a micelle, or otherwise associated with a lipid. Lipid, lipid/DNA or lipid/expression vector associated compositions are not limited to any particular structure in solution. For example, they may be present in a bilayer structure, as micelles, or with a “collapsed” structure. They may also simply be interspersed in a solution, possibly forming aggregates that are not uniform in size or shape. Lipids are fatty substances which may be naturally occurring or synthetic lipids. For example, lipids include the fatty droplets that naturally occur in the cytoplasm as well as the class of compounds which contain long-chain aliphatic hydrocarbons and their derivatives, such as fatty acids, alcohols, amines, amino alcohols, and aldehydes.
Lipids suitable for use can be obtained from commercial sources. For example, dimyristyl phosphatidylcholine (“DMPC”) can be obtained from Sigma, St. Louis, MO; dicetyl phosphate (“DCP”) can be obtained from K & K Laboratories (Plainview, NY); cholesterol (“Choi”) can be obtained from Calbiochem-Behring; dimyristyl phosphatidylglycerol (“DMPG”) and other lipids may be obtained from Avanti Polar Lipids, Inc. (Birmingham, AL.). Stock solutions of lipids in chloroform or chloroform/methanol can be stored at about −20° C. Chloroform is used as the only solvent since it is more readily evaporated than methanol. “Liposome” is a generic term encompassing a variety of single and multilamellar lipid vehicles formed by the generation of enclosed lipid bilayers or aggregates. Liposomes can be characterized as having vesicular structures with a phospholipid bilayer membrane and an inner aqueous medium. Multilamellar liposomes have multiple lipid layers separated by aqueous medium. They form spontaneously when phospholipids are suspended in an excess of aqueous solution. The lipid components undergo self-rearrangement before the formation of closed structures and entrap water and dissolved solutes between the lipid bilayers (Ghosh et al., 1991 Glycobiology 5: 505-10). However, compositions that have different structures in solution than the normal vesicular structure are also encompassed. For example, the lipids may assume a micellar structure or merely exist as nonuniform aggregates of lipid molecules. Also contemplated are lipofectamine-nucleic acid complexes.
Regardless of the method used to introduce exogenous nucleic acids into a host cell or otherwise expose a cell to the molecules described herein, in order to confirm the presence of the nucleic acids in the host cell, a variety of assays may be performed. Such assays include, for example, “molecular biological” assays well known to those of skill in the art, such as Southern and Northern blotting, RT-PCR and PCR; “biochemical” assays, such as detecting the presence or absence of a particular peptide, e.g., by immunological means (ELISAs and Western blots) or by assays described herein to identify agents falling within the scope of the invention.
In some embodiments, any nucleotide sequence herein may be codon-optimized. Without being bound to a particular theory or mechanism, it is believed that codon optimization of the nucleotide sequence increases the translation efficiency of the mRNA transcripts. Codon optimization of the nucleotide sequence may involve substituting a native codon for another codon that encodes the same amino acid, but can be translated by tRNA that is more readily available within a cell, thus increasing translation efficiency. Optimization of the nucleotide sequence may also reduce secondary mRNA structures that would interfere with translation, thus increasing translation efficiency. In some embodiments, the codon-optimized nucleotide sequence may comprise, consist, or consist essentially of any one of the nucleic acid sequences described herein.
In some embodiments, the nucleic acids may be recombinant. As used herein, the term “recombinant” refers to (i) molecules that are constructed outside living cells by joining natural or synthetic nucleic acid segments to nucleic acid molecules that can replicate in a living cell, or (ii) molecules that result from the replication of those described in (i) above. For purposes herein, the replication can be in vitro replication or in vivo replication.
A recombinant nucleic acid may be one that has a sequence that is not naturally occurring or has a sequence that is made by an artificial combination of two otherwise separated segments of sequence. This artificial combination is often accomplished by chemical synthesis or, more commonly, by the artificial manipulation of isolated segments of nucleic acids, e.g., by genetic engineering techniques, such as those described in Green et al., supra. The nucleic acids can be constructed based on chemical synthesis and/or enzymatic ligation reactions using procedures known in the art. See, for example, Green et al., supra. For example, a nucleic acid can be chemically synthesized using naturally occurring nucleotides or variously modified nucleotides designed to increase the biological stability of the molecules or to increase the physical stability of the duplex formed upon hybridization (e.g., phosphorothioate derivatives and acridine substituted nucleotides). Examples of modified nucleotides that can be used to generate the nucleic acids include, but are not limited to, 5-fluorouracil, 5-bromouracil, 5-chlorouracil, 5-iodouracil, hypoxanthine, xanthine, 4-acetylcytosine, 5-(carboxyhydroxymethyl) uracil, 5-carboxymethylaminomethyl-2-thiouridine, 5-carboxymethylaminomethyluracil, dihydrouracil, beta-D-galactosylqueosine, inosine, N6-isopentenyladenine, 1-methyl guanine, 1-methylinosine, 2,2-dimethylguanine, 2-methyladenine, 2-methylguanine, 3-methylcytosine, 5-methylcytosine, N6-substituted adenine, 7-methylguanine, 5-methylaminomethyluracil, 5-methoxyaminomethyl-2-thiouracil, beta-D-mannosylqueosine, 5′-methoxycarboxymethyluracil, 5-methoxyuracil, 2-methylthio-N6-isopentenyladenine, uracil-5-oxyacetic acid (v), wybutoxosine, pseudouracil, queosine, 2-thiocytosine, 5-methyl-2-thiouracil, 2-thiouracil, 4-thiouracil, 5-methyluracil, uracil-5-oxyacetic acid methylester, 3-(3-amino-3-N-2-carboxypropyl) uracil, and 2,6-diaminopurine. Alternatively, one or more of the nucleic acids of the invention can be purchased from companies, such as Macromolecular Resources (Fort Collins, CO) and Synthegen (Houston, TX).
The nucleic acid can comprise any isolated or purified nucleotide sequence which encodes any of the IL-2 reporter systems and/or CAR constructs or functional portions or functional variants thereof. Alternatively, the nucleotide sequence can comprise a nucleotide sequence which is degenerate to any of the sequences or a combination of degenerate sequences.
An embodiment of the invention also provides an isolated or purified nucleic acid comprising a nucleotide sequence which is complementary to the nucleotide sequence of any of the nucleic acids described herein or a nucleotide sequence which hybridizes under stringent conditions to the nucleotide sequence of any of the nucleic acids described herein.
The nucleotide sequence which hybridizes under stringent conditions may hybridize under high stringency conditions. By “high stringency conditions” is meant that the nucleotide sequence specifically hybridizes to a target sequence (the nucleotide sequence of any of the nucleic acids described herein) in an amount that is detectably stronger than non-specific hybridization. High stringency conditions include conditions which would distinguish a polynucleotide with an exact complementary sequence, or one containing only a few scattered mismatches from a random sequence that happened to have a few small regions (e.g., 3-10 bases) that matched the nucleotide sequence. Such small regions of complementarity are more easily melted than a full-length complement of 14-17 or more bases, and high stringency hybridization makes them easily distinguishable. Relatively high stringency conditions would include, for example, low salt and/or high temperature conditions, such as provided by about 0.02-0.1 M NaCl or the equivalent, at temperatures of about 50-70° C. Such high stringency conditions tolerate little, if any, mismatch between the nucleotide sequence and the template or target strand, and are particularly suitable for detecting expression of any of the inventive CAR constructs. It is generally appreciated that conditions can be rendered more stringent by the addition of increasing amounts of formamide.
The invention also provides a nucleic acid comprising a nucleotide sequence that is at least about 70% or more, e.g., about 80%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to any of the nucleic acids described herein.
Aspects of the present disclosure provide methods for using any of the IL-2 reporter systems described herein to assess the efficacy and/or activity of a CAR construct (e.g., a candidate CAR construct) in activating downstream pathways leading to activation of the cells (e.g., T cells). In some embodiments, the downstream pathway is an NFAT-signaling pathway.
In some embodiments, the method involves expressing any of the nucleic acid constructs or vectors described herein in a cell (e.g., a T-lymphocyte) expressing a candidate CAR targeting an antigen. The methods further involve contacting the T-lymphocyte of (i) with an activating agent (e.g., a cell or population of cells expressing the antigen to which the CAR targets). In some embodiments, the method further involves measuring a level of activity of the minimal NFAT-responsive promoter in the T-lymphocyte and comparing the level of activity of the minimal NFAT-responsive promoter to a level of activity of a reference promoter in the T-lymphocyte. In some embodiments, measuring the level of activity of the minimal NFAT-responsive promoter comprises measuring (detecting, quantifying) expression of the reporter molecule under control of the NFAT-responsive promoter. In some embodiments, the level of activity of the reference promoter comprises measuring (detecting, quantifying) expression of a reporter molecule under control of the reference promoter (e.g., a constitutively active promoter). The level of activity of the minimal NFAT-responsive promoter compared to a level of activity of a reference promoter indicates the ability of the CAR to induce NFAT signaling in the cell.
The presence of both a reporter molecule under control of the minimal NFAT-responsive promoter and a reporter molecule under control of a reference promoter (e.g., a constitutively active promoter) in the cell provides a means of assessing NFAT-responsive promoter activity normalized to the reference promoter. The ratio, or activity of the minimal NFAT-responsive promoter relative to a level of activity of a reference promoter, indicates the activity of the candidate CAR construct which can be compared to the activity of additional candidate CAR constructs.
Also within the scope of the present disclosure are kits for use of the IL-2 reporter systems, including nucleic acids and vectors, as well as cells and cell lines expressing any of the reporter systems described herein. Such kits may include one or more containers comprising nucleic acids a reporter molecule encoding (NFAT)-responsive promoter, vectors containing such nucleic acids, and/or cells and cell lines expressing any of the reporter systems described herein.
In some embodiments, the kit can comprise instructions for use in any of the methods described herein. The included instructions can comprise a description of introducing any of the nucleic acids or vectors into a suitable cell or cell line. The kit may further include instructions comprising a description of introducing any of the nucleic acids or vectors encoding a CAR into a suitable cell or cell line. In some embodiments, the instructions comprise a description of performing methods related to the ability of a candidate chimeric antigen receptor (CAR) to induce nuclear factor of activated T cells (NFAT)-signaling in a cell as described herein.
The containers may be unit doses, bulk packages (e.g., multi-dose packages) or sub-unit doses. Instructions supplied in the kits of the disclosure are typically written instructions on a label or package insert.
The kits provided herein are in suitable packaging. Suitable packaging includes, but is not limited to, vials, bottles, jars, flexible packaging, and the like. Also contemplated are support members, such as tissue culture dishes, and multi-well plates, for culturing the cells or cell lines as well as performing methods described herein.
Kits optionally may provide additional components such as buffers and interpretive information. Normally, the kit comprises a container and a label or package insert(s) on or associated with the container. In some embodiment, the disclosure provides articles of manufacture comprising contents of the kits described above.
The practice of the present disclosure will employ, unless otherwise indicated, conventional techniques of molecular biology (including recombinant techniques), microbiology, cell biology, biochemistry, and immunology, which are within the skill of the art. Such techniques are explained fully in the literature, such as Molecular Cloning: A Laboratory Manual, second edition (Sambrook, et al., 1989) Cold Spring Harbor Press; Oligonucleotide Synthesis (M. J. Gait, ed. 1984); Methods in Molecular Biology, Humana Press; Cell Biology: A Laboratory Notebook (J. E. Cellis, ed., 1989) Academic Press; Animal Cell Culture (R. I. Freshney, ed. 1987); Introduction to Cell and Tissue Culture (J. P. Mather and P. E. Roberts, 1998) Plenum Press; Cell and Tissue Culture: Laboratory Procedures (A. Doyle, J. B. Griffiths, and D. G. Newell, eds. 1993-8) J. Wiley and Sons; Methods in Enzymology (Academic Press, Inc.): Handbook of Experimental Immunology (D. M. Weir and C. C. Blackwell, eds.): Gene Transfer Vectors for Mammalian Cells (J. M. Miller and M. P. Calos, eds., 1987; Current Protocols in Molecular Biology (F. M. Ausubel, et al. eds. 1987); PCR: The Polymerase Chain Reaction, (Mullis, et al., eds. 1994); Current Protocols in Immunology (J. E. Coligan et al., eds., 1991); Short Protocols in Molecular Biology (Wiley and Sons, 1999); Immunobiology (C. A. Janeway and P. Travers, 1997); Antibodies (P. Finch, 1997); Antibodies: a practice approach (D. Catty., ed., IRL Press, 1988-1989); Monoclonal antibodies: a practical approach (P. Shepherd and C. Dean, eds., Oxford University Press, 2000); Using antibodies: a laboratory manual (E. Harlow and D. Lane (Cold Spring Harbor Laboratory Press, 1999); The Antibodies (M. Zanetti and J. D. Capra, eds. Harwood Academic Publishers, 1995); DNA Cloning: A practical Approach, Volumes I and II (D. N. Glover ed. 1985); Nucleic Acid Hybridization (B. D. Hames & S. J. Higgins eds. (1985; Transcription and Translation (B. D. Hames & S. J. Higgins, eds. (1984; Animal Cell Culture (R. I. Freshney, ed. (1986; Immobilized Cells and Enzymes (IRL Press, (1986; and B. Perbal, A practical Guide To Molecular Cloning (1984); F. M. Ausubel et al. (eds.).
Without further elaboration, it is believed that one skilled in the art can, based on the above description, utilize the present disclosure to its fullest extent. The following specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever. All publications cited herein are incorporated by reference for the purposes or subject matter referenced herein.
An IL-2 reporter platform was designed for screening of CD33 CAR candidates. The CD33 CAR screening platform utilizes an NFAT-sensitive promoter driving fluorescent protein expression in Jurkat cells. Exemplary nucleic acid constructs were designed to encode a reporter molecule(Fluorescent Protein 2, FP2) operably linked to a minimal NFAT-responsive promoter and a second reporter molecule operably linked to a constitutive promoter (e.g., EF1a) (Fluorescent Protein 1, FP1). The minimal NFAT-responsive promoter contained 6 NFAT binding sites upstream of a minimal IL-2 promoter comprising a TATA box and the coding sequence of the reporter molecule.
Reporter constructs are stably integrated into the Jurkat cell genome (referred to as Step 1 in
An exemplary nucleic acid construct (EF1a_mOrange_IL-2_mTurq) contained the mOrange reporter molecule under control of the constitutively active E1Falpha promoter and mTurquoise reporter molecule (mTurq) under control of the minimal NFAT-responsive promoter. A second exemplary nucleic acid construct (EF1a_mTurq_IL-2_mOrange) contained the mTurquoise reporter molecule under control of the constitutively active E1Falpha promoter and mOrange reporter molecule under control of the minimal NFAT-responsive promoter. The nucleic acids encoding the NFAT-responsive promoters were produced using conventional methods known in the art.
Briefly, two IL-2 reporter cell lines were generated by transducing the lentiviral vectors into Jurkat cells. 1×106 cells/mL were activated using 2 μL phorbol myristate acetate (PMA) and ionomycin (a T-cell activation cocktail (see, e.g., BioLegend Activation Cocktail) for 24 hours and assessed for expression of each of the reporter molecules as well as CD69, an indicator of T cell activation, using flow cytometry. As shown in
Cells were also assessed for expression of each of the reporter molecules by fluorescence microscopy. Both reporter cell lines exhibited constitutive expression of their respective FP1 genes under the control of the EF1α promoter and no fluorescence of their respective FP2 genes under the control of the IL-2 fluorescence in the absence of PMA/ionomycin. Treatment of the cell lines with PMA and ionomycin induced expression of the FP2 fluorescent proteins from both constructs (
To further characterize the expression kinetics of both NFAT-responsive promoter constructs, transduced Jurkat cells were cultured in the presence or absence of PMA and ionomycin and then monitored for 24 hours using IncuCyte Live-Cell analyses. Increases in FP2 fluorescence were observed ˜5 hours after treatment for the EF1α_mOrange_IL-2_mTurquoise reporter cell line and ˜10 hours after treatment for the EF1α_mTurquoise_IL-2_mOrange reporter cell line. Peak expression occurred at 13 to 15 hours after treatment, and both cell lines maintained measurable FP2 fluorescence for at least 24 hours after treatment (
These results indicate that the minimal NFAT-responsive promoter induces expression of the reporter molecule when activated. Expression of the reporter molecule under control of the minimal NFAT-responsive promoter relative to expression of reporter molecule under control of EF1a (the constitutive promoter) provides a means of normalizing expression to account for factors, such as any differing transduction efficiencies between the constructs.
To screen CD33 CAR candidates, flow cytometry analyses were established in Jurkat lines transduced with the reporter constructs described herein. Viable cells were gated for expression of anti-CD33 CARs (CD33 CAR+) and FP1 (FP1+). Then, FP1-positive cells were analyzed for FP2 expression (FP2+) upon co-culture with CD33+MOLM13WT and CD33KO cells. FP2 expression in response to CD33KO cells (deficient in the target antigen) were used to determine background expression levels (
Detection of the fluorescent proteins was also assessed by flow cytometry. Briefly, reporter cell lines were activated with PMA and ionomycin (a T-cell activation cocktail (see, e.g., BioLegend Activation Cocktail) for 24 hours and assessed for expression of each of the reporter molecules as well as CD69, an indicator of T cell activation. As shown in
These results indicate that the minimal NFAT-responsive promoter induces expression of the reporter molecule when activated. Expression of the reporter molecule under control of the minimal NFAT-responsive promoter relative to expression of reporter molecule under control of EF1a (the constitutive promoter) provides a means of normalizing expression to account for factors, such as any differing transduction efficiencies between the constructs.
As an example antigen, CAR constructs were designed to target CD33. CD33, also known as Siglec (Sialic-acid-binding immunoglobulin-like lectin) plays a role in mediating cell-cell interactions and in maintaining immune cells in a resting state. CD33 is expressed on the surface of the vast majority of AML blasts and chronic myeloid leukemia in blast crisis. It is also aberrantly expressed on a subset of T cell acute lymphoblastic leukemias. Normal tissue expression is restricted to normal myeloid cells. Currently, treating AML with a therapy that targets CD33 can be effective, but the therapy may be limited in utility due to toxicity to the normal blood and bone marrow. The methods described herein allow for comparison of CAR constructs, such as the activity and function of the CAR constructs, as well as high-throughput screening methods for identifying CAR constructs having desired properties (e.g., level of activation of T cells). Example CAR constructs are known in the art. See for example, PCT Publication No. WO 2019/178382 A1, as well as Kenderian, et al. Leukemia (2015) 29: 1637-1647.
Reporter cells containing the exemplary nucleic acid constructs EF1a_mOrange_IL-2_mTurq and EF1a_mTurq_IL-2_mOrange were generated as described in Example 1. The cells were transduced with the 8 different exemplary CD33 CARs shown in
Following co-culture, expression of the reporter molecules was assessed by flow cytometry. Cells were gated on mOrange-expressing Jurkat cells, which indicates cells that were transduced with the nucleic acid construct and are able to express the reporter construct, as the FP1 reporter is under control of the EF1a promoter. Next, expression of the FP2 reporter was determined in each co-culture for each of the CD33 CAR constructs as a percentage of FP2-positive cells (of FP1-positive cells) A ratio was determined for expression of the FP2 reporter when co-cultured in the presence to wild-type MOLM-13 cells (CD33+) relative to expression of the FP2 reporter when co-cultured in the presence to MOLM-13 CD33KO cells (CD33−) to determine activity of the CD33 CAR (CD33-specific activation). (
Results indicate that the IL-2 reporter system cells can be used as an objective and reliable reporter system for comparing activity of CAR constructs. Assessing expression of a reporter molecule that is constitutively expressed eliminates false outcomes, potentially due to altered transduction efficiencies, and verifies successful transduction of the reporter construct. Expression of the reporter molecule, driven only in activated cells, represents antigen recognition by and activity of the CAR construct.
Reporter cells containing the exemplary nucleic acid constructs EF1a_mOrange_IL-2_mTurq and EF1a_mTurq_IL-2_mOrange were generated and transduced with the 8 different exemplary CD33 CARs as described in Example 2. Cells were co-cultured for 24 hours with either wild-type MOLM13 cells (CD33+) or MOLM13 cells that are deficient for CD33 (MOLM13 CD33KO). Expression of the fluorescent reporters was detected by flow cytometry.
The expression of FP2 after MOLM13 co-culture was compared to expression of FP2 after MOLM13 CD33KO co-culture as fold increase from baseline (
Expression of CD69, a marker of T cell activation, was also assessed by flow cytometry. The percentage of CD69+FP1+ cells was plotted as fold increase (
All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
The use of the terms “a” and “an” and “the” and “at least one” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The use of the term “at least one” followed by a list of one or more items (for example, “at least one of A and B”) is to be construed to mean one item selected from the listed items (A or B) or any combination of two or more of the listed items (A and B), unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein.
Articles such as “a,” “an,” and “the” may mean one or more than one unless indicated to the contrary or otherwise evident from the context. Claims or descriptions that include “or” between two or more members of a group are considered satisfied if one, more than one, or all of the group members are present, unless indicated to the contrary or otherwise evident from the context. The disclosure of a group that includes “or” between two or more group members provides embodiments in which exactly one member of the group is present, embodiments in which two or more members of the group are present, and embodiments in which all of the group members are present. For purposes of brevity those embodiments have not been individually spelled out herein, but it will be understood that each of these embodiments is provided herein and may be specifically claimed or disclaimed.
It is to be understood that the invention encompasses all variations, combinations, and permutations in which one or more limitation, element, clause, or descriptive term, from one or more of the claims or from one or more relevant portion of the description, is introduced into another claim. For example, a claim that is dependent on another claim can be modified to include one or more of the limitations found in any other claim that is dependent on the same base claim. Furthermore, where the claims recite a composition, it is to be understood that methods of making or using the composition according to any of the methods of making or using disclosed herein or according to methods known in the art, if any, are included, unless otherwise indicated or unless it would be evident to one of ordinary skill in the art that a contradiction or inconsistency would arise.
Where elements are presented as lists, e.g., in Markush group format, it is to be understood that every possible subgroup of the elements is also disclosed, and that any element or subgroup of elements can be removed from the group. It is also noted that the term “comprising” is intended to be open and permits the inclusion of additional elements or steps. It should be understood that, in general, where an embodiment, product, or method is referred to as comprising particular elements, features, or steps, embodiments, products, or methods that consist, or consist essentially of, such elements, features, or steps, are provided as well. For purposes of brevity those embodiments have not been individually spelled out herein, but it will be understood that each of these embodiments is provided herein and may be specifically claimed or disclaimed.
Where ranges are given, endpoints are included. Furthermore, it is to be understood that unless otherwise indicated or otherwise evident from the context and/or the understanding of one of ordinary skill in the art, values that are expressed as ranges can assume any specific value within the stated ranges in some embodiments, to the tenth of the unit of the lower limit of the range, unless the context clearly dictates otherwise. For purposes of brevity, the values in each range have not been individually spelled out herein, but it will be understood that each of these values is provided herein and may be specifically claimed or disclaimed. It is also to be understood that unless otherwise indicated or otherwise evident from the context and/or the understanding of one of ordinary skill in the art, values expressed as ranges can assume any subrange within the given range, wherein the endpoints of the subrange are expressed to the same degree of accuracy as the tenth of the unit of the lower limit of the range.
In addition, it is to be understood that any particular embodiment of the present invention may be explicitly excluded from any one or more of the claims. Where ranges are given, any value within the range may explicitly be excluded from any one or more of the claims. Any embodiment, element, feature, application, or aspect of the compositions and/or methods of the invention, can be excluded from any one or more claims. For purposes of brevity, all of the embodiments in which one or more elements, features, purposes, or aspects is excluded are not set forth explicitly herein.
The scope of the present invention is not intended to be limited to the above Description, but rather is as set forth in the following claims
This application claims the benefit under 35 U.S.C. 119(e) of U.S. Provisional Application No. 63/227,046 filed Jul. 29, 2021 and U.S. Provisional Application No. 63/278,613 filed Nov. 12, 2021, each of which are incorporated by reference herein in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2022/074313 | 7/29/2022 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63278613 | Nov 2021 | US | |
| 63227046 | Jul 2021 | US |
