Patent Application
20240101650
This disclosure relates generally to antibodies against Mycobacterium tuberculosis surface polysaccharide arabinomannan (AM) and methods of use thereof.
With over 10 million cases per year and one million associated deaths, active tuberculosis (TB), caused by the facultative intracellular Mycobacterium tuberculosis (Mtb), is, after COVID-19, the leading cause of death from a single infectious agent. While an estimated quarter of the world is latently infected with Mtb, TB is caused by uncontrolled infection leading to a predominantly respiratory and transmissible disease.
The capsule of microorganisms, including Mtb, is an important virulence factor. Antibodies (Abs) to capsular and surface polysaccharides are protective against infections with encapsulated extra- and intracellular pathogens. Some successful vaccines are based on inducing Abs to capsular polysaccharides. The mechanisms by which Abs protect against Mycobacterium tuberculosis (Mtb) have been insufficiently studied because of the general belief that Mtb, a predominantly intracellular organism, is outside the reach of extracellular located Abs. However, Abs contribute to the defense against many intracellular pathogens, including Mtb, through various functions, including interactions with Fc receptors (FcR) and the modulation of innate and other immune responses.
The majority of the mycobacterial capsule is composed of polysaccharides and proteins; lipids are a minor component of the capsule. The three major capsular polysaccharides are α-glucan, arabinomannan (AM), and mannan. The 13-20 kDa, immunogenic polysaccharide AM can be isolated from the capsule of Mtb.
The cell walls and membranes of mycobacteria comprise lipoarabinomannan (LAM), a glycolipid that comprises AM. Both AM and LAM are very immunogenic. Some but not all murine monoclonal antibodies (mAbs) to AM/LAM show protective in vivo efficacy, and immunization with AM/LAM-protein conjugates improves the outcome of Mtb infected mice. However, these studies are limited in capturing the tremendous complexity and heterogeneity of potentially Mtb protective antibodies in humans. Nevertheless, they are consistent with the data that not all ‘anti-AM’ mAbs have the same binding specificity or protective ability. Several recent studies provide compelling data suggesting that Mtb specific antibodies have a role in controlling Mtb infection in humans and could be protective but very little is known about the functions of antigen-specific human mAbs in Mtb infection.
Accordingly, to combat the major global public health problem caused by TB, ongoing development of additional tools for both research and clinical care is critical to meet the continuing urgent need for the rapid detection, treatment, and prevention of Mtb infection. Beyond their potential to inform vaccine and immunotherapy development, antibodies are versatile and indispensable tools in a plethora of applications in medicine and research, including the detection of pathogens and their antigens.
Additionally, there is an urgent need for a simple, yet highly sensitive non-sputum-based point-of-care (POC) test. To have an impact on global TB control, a non-sputum-based POC needs to be all—accurate, robust, and suitable for the use of community health care providers in resource-limited settings. The most promising approach to achieve these criteria is the detection of the M. tuberculosis (Mtb) surface glycolipid lipoarabinomannan (LAM) in urine via a lateral flow format. The AlereLAM dipstick test, however, has a sensitivity <50% in HIV-associated TB (<20% in non-HIV TB) with an inverse correlation between sensitivity and CD4 cells, and relies on polyclonal rabbit sera for LAM capture and detection. The recently developed next generation FujiLAM test uses two new anti-LAM monoclonal antibodies (mAbs) and has higher sensitivity. However, it is less simple, requires an extra silver amplification step, and its sensitivity for TB is <50% in PLHIV with >200 CD4 cells (˜50% in non-HIV TB). Therefore, additional tools such as high-affinity mAbs that bind to AM/LAM for simple POC diagnosis TB are urgently needed.
In one aspect, provided is an anti-Mycobacterium tuberculosis arabinomannan (anti-Mtb AM) antibody, or Mycobacterium tuberculosis arabinomannan-binding fragment (Mtb AM-binding fragment) thereof, wherein the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, comprises a heavy chain variable region and a light chain variable region, wherein each of the heavy chain and the light chain variable regions comprises a CDR1, CDR2, and CDR3; and wherein CDR1H comprises SEQ ID NO:1, CDR2H comprises SEQ ID NO:2, CDR3H comprises SEQ ID NO:3, CDR1L comprises SEQ ID NO:3, CDR2L comprises SEQ ID NO:5, and CDR3L comprises SEQ ID NO:6.
In one aspect, provided is anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, wherein the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, comprises a heavy chain variable region and a light chain variable region, wherein each of the heavy chain and the light chain variable regions comprises a CDR1, CDR2, and CDR3; and wherein CDR1H comprises SEQ ID NO:26, CDR2H comprises SEQ ID NO:27, CDR3H comprises SEQ ID NO:28, CDR1L comprises SEQ ID NO:29, CDR2L comprises SEQ ID NO:30, and CDR3L comprises SEQ ID NO:31.
In one embodiment, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, comprises a heavy chain variable region that is at least 80% identical to SEQ ID NO:7 and a light chain variable region that is at least 80% identical to SEQ ID NO:8.
In one embodiment, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, comprises a heavy chain variable region that is at least 80% identical to SEQ ID NO:32 and a light chain variable region that is at least 80%, identical to SEQ ID NO:34.
In one embodiment, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, comprises a heavy chain variable region that comprises SEQ ID NO:7 and a light chain variable region that comprises SEQ ID NO:8.
In one embodiment, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, comprises a heavy chain variable region that comprises SEQ ID NO:32 and a light chain variable region that comprises SEQ ID NO:34.
In one embodiment, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, is a monoclonal antibody.
In one embodiment, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, comprises (i) a VH framework comprising the framework sequence of human germline VH 3-23*01; and/or (ii) a VK framework comprising the framework sequence of human germline 2-24*01.
In one embodiment, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, comprises (i) a VH framework comprising the framework sequence of human germline VH 4-59*08; and/or (ii) a VL framework comprising the framework sequence of human germline VL 1-51*02.
In one embodiment, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, is a recombinant antibody.
In one embodiment, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, comprises a human framework region or a modified human framework region.
In one embodiment, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, comprises a human constant region or a modified human constant region.
In one embodiment, the Mtb AM-binding fragment is an scFv, Fv, Fab′, Fab, F(ab′)2, or diabody.
In one embodiment, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, is deglycosylated.
In one embodiment, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, is conjugated to one or more of a cytotoxin, a fluorescent label, and an imaging agent.
Provided herein is a nucleic acid molecule encoding an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein. In one embodiment, nucleic acid molecule is an isolated nucleic acid molecule.
In one embodiment, the nucleic acid molecule comprises SEQ ID NO:9 and/or SEQ ID NO: 10. In one embodiment, the nucleic acid molecule comprises SEQ ID NO:33 and/or SEQ ID NO:35.
Provided herein is a vector or set of vectors comprising one or more nucleic acid molecules disclosed herein. Provided herein is a vector or set of vectors comprising a nucleic acid molecule encoding an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein.
Provided herein is a host cell comprising a nucleic acid molecule or a vector disclosed herein. Provided herein is a host cell comprising a nucleic acid molecule encoding an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein. Provided herein is a host cell comprising vector comprising a nucleic acid molecule encoding an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein. The cell may be isolated.
In one aspect, provided is a method of producing an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, comprising culturing a host cell comprising vector comprising a nucleic acid molecule encoding an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein, under conditions wherein the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, is produced by the host cell.
In one embodiment, provided is a pharmaceutical composition comprising an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein, and a pharmaceutically acceptable excipient.
In one aspect, provided is a method of reducing an activity of Mycobacterium tuberculosis AM in a subject in need thereof, the method comprising administering to said subject a therapeutically effective amount of an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein.
In one aspect, provided is a method of reducing an activity of Mycobacterium tuberculosis AM in a subject in need thereof, the method comprising administering to said subject a therapeutically effective amount of a pharmaceutical composition, wherein the pharmaceutical composition comprises an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein, and a pharmaceutically acceptable excipient.
In one aspect, provided is a method of treating a Mycobacterium tuberculosis infection in a subject, the method comprising administering to the subject an amount of an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein, wherein the amount is effective to treat a Mycobacterium tuberculosis infection.
In one aspect, provided is a method of treating a Mycobacterium tuberculosis infection in a subject, the method comprising administering to the subject an amount of a pharmaceutical composition, wherein the amount is effective to treat a Mycobacterium tuberculosis infection, and wherein the pharmaceutical composition comprises an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein, and a pharmaceutically acceptable excipient.
In one aspect, provided is a method of reducing the likelihood of a Mycobacterium tuberculosis infection in a subject, the method comprising administering to the subject who does not have a Mycobacterium tuberculosis infection an amount of an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein, wherein the amount is effective to reduce the likelihood of a Mycobacterium tuberculosis infection.
In one aspect, provided is a method of reducing the likelihood of a Mycobacterium tuberculosis infection in a subject, the method comprising administering to the subject who does not have a Mycobacterium tuberculosis infection an amount of a pharmaceutical composition, wherein the pharmaceutical composition comprises an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein, and a pharmaceutically acceptable excipient, and wherein the amount is effective to reduce the likelihood of a Mycobacterium tuberculosis infection.
In one aspect, provided is a method of treating a disease, disorder, or condition mediated by, or related to increased activity of Mycobacterium tuberculosis in a subject, the method comprising administering to said subject a therapeutically effective amount of an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein.
In one aspect, provided is a method of treating a disease, disorder, or condition mediated by, or related to increased activity of Mycobacterium tuberculosis in a subject, the method comprising administering to said subject a therapeutically effective amount of a pharmaceutical composition, wherein the pharmaceutical composition comprises an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein, and a pharmaceutically acceptable excipient.
An assay device is provided for selectively detecting one or more bacteria from the Mycobacterium tuberculosis complex (MTC) group in a biological sample comprising: a first portion comprising a first plurality of anti-Mtb AM-antibodies, or Mtb AM-binding fragments thereof, as described herein, or anti-mycobacterial AM-antibodies, wherein the antibodies or fragments are each attached to their own reporting entity; and a second portion comprising a second plurality of anti-Mtb AM-antibodies, or Mtb AM-binding fragments thereof, or anti-mycobacterial AM-antibodies.
In some embodiments, the second plurality of anti-Mycobacterium tuberculosis antibodies, comprises antibodies comprising a heavy chain variable region and a light chain variable region, wherein the heavy chain and the light chain variable regions comprises a CDR1, CDR2, and CDR3; and wherein CDR1H comprises SEQ ID NO:17, CDR2H comprises SEQ ID NO:18, CDR3H comprises SEQ ID NO:19, CDR1L comprises SEQ ID NO:20, CDR2L comprises SEQ ID NO:21, and CDR3L comprises SEQ ID NO:22.
Provided herein is an assay device for selectively detecting one or more bacteria from the Mycobacterium tuberculosis complex (MTC) group in a biological sample comprising:
Provided herein is an assay device for selectively detecting AM or LAM from the Mycobacterium tuberculosis complex (MTC) group in a biological sample comprising:
In one embodiment, the reporting entity comprises a gold nanoparticle. In one embodiment, the reporting entity comprises an enzyme. In some embodiments, the enzyme is horseradish peroxidase (HRP) or alkaline phosphatase (AP).
In some embodiments, the second plurality of anti-Mtb AM-antibodies, or Mtb AM-binding fragments thereof, or anti-mycobacterial AM-antibodies is affixed to a solid support of the device.
In some embodiments, the first plurality of second plurality of anti-Mtb AM-antibodies, or Mtb AM-binding fragments thereof, or anti-mycobacterial AM-antibodies is not affixed to a solid support of the device.
In some embodiments, the solid support comprises nitrocellulose.
In some embodiments, the assay device further comprises a fluid sample pad prior in sequential order to the first and second portions. In some embodiments, the assay device further comprises a control portion subsequent in sequential order to the first and second portions.
In some embodiments, the control portion comprises a third plurality of antibodies, immobilized on a solid support of the device, and which third plurality of antibodies are capable of binding the first plurality of anti-Mtb AM-antibodies, or Mtb AM-binding fragments thereof, or anti-mycobacterial AM-antibodies each attached to their own reporting molecule.
In some embodiments, assay device further comprises a fluid-absorbent wicking pad subsequent in sequential order to the first and second portions, and third portion if present.
In some embodiments, the assay device is a lateral flow assay device.
In one aspect, provided is a method of detecting one or more bacteria from the MTC group in a biological sample comprising: (a) contacting an assay device disclosed herein with the sample; and (b) observing if one or more bacteria from the MTC group bind to the second plurality of anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, or anti-mycobacterial AM-antibodies; wherein if one or more bacteria from the MTC group bind to the second plurality of anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, or anti-mycobacterial AM-antibodies, then one or more bacteria from the MTC group bind have been detected in the biological sample; and wherein if no bacteria from the MTC group bind to the second plurality of anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, or anti-mycobacterial AM-antibodies, then bacteria from the MTC group have not been detected in the biological sample. In some embodiments, the method further comprises obtaining the sample from a subject.
In some embodiments, the sample is urine, cerebrospinal fluid, pleural fluid, peritoneal fluid, sputum, saliva, a tissue sample, or a fine-needle aspirate.
In some embodiments, the subject is human.
The disclosure provides antibodies and an antigen-binding fragments thereof that bind to Mycobacterium tuberculosis arabinomannan (AM) and the AM portion of lipoarabinomannan (LAM), as well as methods of using such antibodies and an antigen-binding fragments thereof. In embodiments, the antibodies or antigen-binding fragments thereof disclosed herein bind to bacteria from the Mycobacterium tuberculosis complex (MTC) group or AM/LAM from bacteria from MTC.
The term “antibody” is used in the broadest sense and includes monoclonal antibodies (including full length or intact monoclonal antibodies), polyclonal antibodies, multivalent antibodies, multispecific antibodies (e.g., bispecific antibodies).
As used herein, “antibody variable domain” refers to the portions of the light and heavy chains of antibody molecules that include amino acid sequences of complementarity determining regions (CDRs; i.e., CDR1, CDR2, and CDR3), and framework regions. VH refers to the variable domain of the heavy chain. VL refers to the variable domain of the light chain. The term “framework regions” refers to those variable domain residues other than the CDR residues. Further, the “light chains” of antibodies (immunoglobulins) from any vertebrate species can be assigned to one of two clearly distinct types, called kappa (κ) and lambda (λ), based on the amino acid sequences of their constant domains.
As used herein, the term “complementarity determining regions” refers to portions of an antibody variable domain that are (typically, but not always) involved in antigen binding. Each variable domain typically has three CDR regions identified as CDR1, CDR2 and CDR3. Each CDR can comprise amino acid residues from a CDR as defined by e.g. Kabat (Kabat et al., Sequences of Proteins of Immunological Interest, 5th Ed. Public Health Service, National Institutes of Health, Bethesda, Md. (1987, 1991)). Each CDR can also comprise amino acid residues from a “hypervariable loop” as defined by Chothia (Chothia & Lesk 196 J. Mol. Biol. 901 (1987)). In some instances, a CDR can include amino acids from both a CDR region defined according to Kabat and a hypervariable loop. The Kabat residue designations do not always correspond directly with the linear numbering of the amino acid residues (primary amino acid sequence). The actual linear amino acid sequence may contain fewer or additional amino acids than in the strict Kabat numbering corresponding to a shortening of, or insertion into, a structural component, whether framework or CDR, of the basic variable domain structure. The correct Kabat numbering of residues may be determined for a given antibody or antigen-binding fragment thereof by alignment of residues of homology in the sequence of the antibody or antigen-binding fragment thereof with a “standard” Kabat numbered sequence. Alternatively, a CDR may be defined according to the ImMunoGeneTics (IMGT) system (Lefranc, M.-P. et al., Dev. Comp. Immunol., 27, 55-77 (2003)).
Provided herein is an anti-Mycobacterium tuberculosis arabinomannan (anti-Mtb AM) antibody, or Mycobacterium tuberculosis arabinomannan-binding fragment (Mtb AM-binding fragment) thereof, wherein said antibody or fragment thereof comprises a heavy chain variable region and a light chain variable region, wherein each of the heavy chain and the light chain variable regions comprises a CDR1, CDR2, and CDR3; and wherein CDR1H comprises SEQ ID NO:1, CDR2H comprises SEQ ID NO:2, CDR3H comprises SEQ ID NO:3, CDR1L comprises SEQ ID NO:4, CDR2L comprises SEQ ID NO:5, and CDR3L comprises SEQ ID NO:6.
Provided herein is an anti-Mycobacterium tuberculosis arabinomannan (anti-Mtb AM) antibody, or Mycobacterium tuberculosis arabinomannan-binding fragment (Mtb AM-binding fragment) thereof, wherein said antibody or fragment thereof comprises a heavy chain variable region and a light chain variable region, wherein each of the heavy chain and the light chain variable regions comprises a CDR1, CDR2, and CDR3; and wherein CDR1H comprises SEQ ID NO:11, CDR2H comprises SEQ ID NO:12, CDR3H comprises SEQ ID NO: 13, CDR1L comprises SEQ ID NO:14, CDR2L comprises SEQ ID NO:15, and CDR3L comprises SEQ ID NO:16.
Provided herein is an anti-Mycobacterium tuberculosis arabinomannan (anti-Mtb AM) antibody, or Mycobacterium tuberculosis arabinomannan-binding fragment (Mtb AM-binding fragment) thereof, wherein said antibody or fragment thereof comprises a heavy chain variable region and a light chain variable region, wherein each of the heavy chain and the light chain variable regions comprises a CDR1, CDR2, and CDR3; and wherein CDR1H comprises SEQ ID NO:26, CDR2H comprises SEQ ID NO:27, CDR3H comprises SEQ ID NO:28, CDR1L comprises SEQ ID NO:29, CDR2L comprises SEQ ID NO:30, and CDR3L comprises SEQ ID NO:31.
Provided herein is an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, that comprises a heavy chain variable region that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:7.
Provided herein is an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, that comprises a light chain variable region that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:8.
Provided herein is an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, that comprises (1) a heavy chain variable region that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:7 and (2) a light chain variable region that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:8.
Provided herein is an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, that comprises (1) a heavy chain variable region that is at least 95% identical to SEQ ID NO:7 and (2) a light chain variable region that is at least 95% identical to SEQ ID NO:8.
Provided herein is an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, that comprises (1) a heavy chain variable region that is at least 96% identical to SEQ ID NO:7 and (2) a light chain variable region that is at least 96% identical to SEQ ID NO:8
Provided herein is an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, that comprises (1) a heavy chain variable region that is at least 97% identical to SEQ ID NO:7 and (2) a light chain variable region that is at least 97% identical to SEQ ID NO: 8.
Provided herein is an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, that comprises (1) a heavy chain variable region that is at least 98% identical to SEQ ID NO:7 and (2) a light chain variable region that is at least 98% identical to SEQ ID NO:8.
Provided herein is an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, that comprises (1) a heavy chain variable region that is at least 99% identical to SEQ ID NO:7 and (2) a light chain variable region that is at least 99% identical to SEQ ID NO:8
Provided herein is an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, that comprises (1) a heavy chain variable region comprising SEQ ID NO:7 and (2) a light chain variable region comprising SEQ ID NO:8
Provided herein is an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, that comprises a heavy chain variable region that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:32.
Provided herein is an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, that comprises a light chain variable region that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:34.
Provided herein is an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, that comprises (1) a heavy chain variable region that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:32 and (2) a light chain variable region that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:34.
Provided herein is an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, that comprises (1) a heavy chain variable region that is at least 95% identical to SEQ ID NO:32 and (2) a light chain variable region that is at least 95% identical to SEQ ID NO:34.
Provided herein is an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, that comprises (1) a heavy chain variable region that is at least 96% identical to SEQ ID NO:32 and (2) a light chain variable region that is at least 96% identical to SEQ ID NO:34
Provided herein is an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, that comprises (1) a heavy chain variable region that is at least 97% identical to SEQ ID NO:32 and (2) a light chain variable region that is at least 97% identical to SEQ ID NO:34.
Provided herein is an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, that comprises (1) a heavy chain variable region that is at least 98% identical to SEQ ID NO:32 and (2) a light chain variable region that is at least 98% identical to SEQ ID NO:34.
Provided herein is an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, that comprises (1) a heavy chain variable region that is at least 99% identical to SEQ ID NO:32 and (2) a light chain variable region that is at least 99% identical to SEQ ID NO:34
Provided herein is an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, that comprises (1) a heavy chain variable region comprising SEQ ID NO:32 and (2) a light chain variable region comprising SEQ ID NO:34
Provided herein is an anti-Mycobacterium tuberculosis arabinomannan (anti-Mtb AM) antibody, or Mycobacterium tuberculosis arabinomannan-binding fragment (Mtb AM-binding fragment) thereof, wherein said antibody or fragment thereof comprises a heavy chain variable region and a light chain variable region, wherein each of the heavy chain and the light chain variable regions comprises a CDR1, CDR2, and CDR3; and wherein:
Provided herein is an anti-Mycobacterium tuberculosis arabinomannan (anti-Mtb AM) antibody, or Mycobacterium tuberculosis arabinomannan-binding fragment (Mtb AM-binding fragment) thereof, wherein said antibody or fragment thereof comprises a heavy chain variable region and a light chain variable region, wherein each of the heavy chain and the light chain variable regions comprises a CDR1, CDR2, and CDR3; and wherein:
Provided herein is an anti-Mycobacterium tuberculosis arabinomannan (anti-Mtb AM) antibody, or Mycobacterium tuberculosis arabinomannan-binding fragment (Mtb AM-binding fragment) thereof, wherein said antibody or fragment thereof comprises a heavy chain variable region and a light chain variable region, wherein each of the heavy chain and the light chain variable regions comprises a CDR1, CDR2, and CDR3; and wherein:
As used herein, the term “identity” refers to sequence identity between two nucleic acid molecules or polypeptides. Identity can be determined by comparing a position in each sequence, which may be aligned for purposes of comparison. For example, when a position in the compared nucleotide sequence is occupied by the same base, then the molecules are identical at that position. A degree identity between nucleic acid or amino acid sequences is a function of the number of identical or matching nucleotides or amino acids at shared positions. For example, polypeptides having at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity to specific polypeptides described herein and preferably exhibiting substantially the same functions, as well as polynucleotides encoding such polypeptides, are contemplated. Methods and computer programs for determining both sequence identity and similarity are publicly available, including, but not limited to, the GCG program package (Devereux et al., Nucleic Acids Research 12: 387, 1984), BLASTP, BLASTN, FASTA (Altschul et al., J. Mol. Biol. 215:403 (1990), and the ALIGN program (version 2.0). The well-known Smith Waterman algorithm may also be used to determine similarity. The BLAST program is publicly available from NCBI and other sources (BLAST Manual, Altschul, et al., NCBI NLM NIH, Bethesda, Md. 20894; BLAST 2.0 at http://www.ncbi.nlm.nih.gov/blast/). In comparing sequences, these methods account for various substitutions, deletions, and other modifications.
The antibodies disclosed herein may comprises modifications in their variable and their constant regions. For example, provides herein are antibodies comprising modified, but functionally equivalent variable regions and/or CDRs. In some embodiments, the modification does not significantly affect the properties of the antibody or antigen-binding fragment thereof. In some embodiments, the modification leads to enhanced or decreased activity and/or affinity. For example, the amino acid sequence may be mutated to obtain an antibody with the desired binding affinity to Mtb AM. Modification of polypeptides is routine practice in the art and need not be described in detail herein. Examples of modified polypeptides include polypeptides with conservative substitutions of amino acid residues, one or more deletions or additions of amino acids which do not significantly deleteriously change the functional activity, or which mature (enhance) the affinity of the polypeptide for its ligand, or use of chemical analogs.
Amino acid sequence insertions include amino- and/or carboxyl-terminal fusions ranging in length from one residue to polypeptides containing a hundred or more residues, as well as intra-sequence insertions of single or multiple amino acid residues. Examples of terminal insertions include an antibody with an N-terminal methionyl residue or the antibody fused to an epitope tag. Other insertional variants of the antibody molecule include the fusion to the N- or C-terminus of the antibody or antigen-binding fragment thereof with an enzyme or a polypeptide which increases the half-life of the antibody in the blood circulation.
Substitution variants of the antibodies and antigen-binding fragments thereof have at least one amino acid residue in the antibody molecule removed and a different residue inserted in its place. Substitutional mutagenesis may be directed to the hypervariable regions, but framework alterations are also contemplated. Examples of conservative substitutions are shown in Table 1.
Naturally occurring residues are divided into groups based on common side-chain properties:
Conservative substitutions can also be made by exchanging a member of one of these classes for another member of the class.
One type of substitution, for example, that may be made is to change one or more cysteines in the antibody, which may be chemically reactive, to another residue, such as, without limitation, alanine or serine. For example, there can be a substitution of a non-canonical cysteine. The substitution can be made in a CDR or framework region of a variable domain or in the constant region of an antibody. In some embodiments, the cysteine is canonical. Any cysteine residue not involved in maintaining the proper conformation of the antibody also may be substituted, generally with serine, to improve the oxidative stability of the molecule and prevent aberrant cross-linking. Conversely, cysteine bond(s) may be added to the antibody to improve its stability, particularly where the antibody is an antibody fragment such as an Fv fragment.
In embodiments, the anti-Mtb AM antibody is a monoclonal antibody or the anti-Mtb AM-binding fragment thereof is a fragment of a monoclonal antibody. The term “monoclonal antibody” as used herein refers to an antibody member of a population of substantially homogeneous antibodies, i.e., the individual antibodies comprising the population are identical except for possible mutations, e.g., naturally occurring mutations, that may be present in minor amounts. Thus, the modifier “monoclonal” indicates the character of the antibody as not being a mixture of discrete antibodies. In certain embodiments, such a monoclonal antibody typically includes an antibody comprising a polypeptide sequence that binds a target an Mtb capsular AM, wherein the target-binding polypeptide sequence was obtained by a process that includes the selection of a single target binding polypeptide sequence from a plurality of polypeptide sequences. For example, the selection process can be the selection of a unique clone from a plurality of clones, such as a pool of hybridoma clones, phage clones, or recombinant DNA clones. 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. In addition to their specificity, monoclonal antibody preparations are advantageous in that they are typically uncontaminated by other immunoglobulins. Thus, an identified monoclonal antibody can be produced by non-hybridoma techniques, e.g., by appropriate recombinant means once the sequence thereof is identified.
In some embodiments, the anti-Mtb AM antibody is a human antibody and/or the anti-Mtb AM-binding fragment thereof is a fragment of a human antibody. As used herein, a “human antibody” is one whose sequences correspond to (i.e., are identical in sequence to) an antibody that could be produced by a human and/or has been made using any of the techniques for making human antibodies as disclosed herein, but not one which has been made in a human. A “human antibody” as used herein can be produced using various techniques known in the art, including phage-display libraries (Hoogenboom and Winter, J. Mol. Biol., 227:381 (1991); Marks et al., J. Mol. Biol., 222:581 (1991), hereby incorporated by reference in their entireties, by methods described in Cole et al., Monoclonal Antibodies and Cancer Therapy, Alan R. Liss, p. 77 (1985) hereby incorporated by reference in its entirety; Boemer et al., J. Immunol., 147(1):86-95 (1991) hereby incorporated by reference in its entirety, van Dijk and van de Winkel, Curr. Opin. Pharmacol., 5: 368-74 (2001) hereby incorporated by reference in its entirety, and by administering the antigen (e.g., Mtb capsular AM or an entity comprising such) to a transgenic animal that has been modified to produce such antibodies in response to antigenic challenge, but whose endogenous loci have been disabled, e.g., immunized xenomice (see, e.g., U.S. Pat. Nos. 5,939,598; 6,075,181; 6,114,598; 6,150,584 and 6,162,963 to Kucherlapati et al. regarding XENOMOUSE™ technology, each of which patents are hereby incorporated by reference in their entireties), e.g., VelocImmune® (Regeneron, Tarrytown, NY), e.g., UltiMab® platform (Medarex, now Bristol Myers Squibb, Princeton, NJ). See also, for example, Li et al., Proc. Natl. Acad. Sci. USA, 103:3557-3562 (2006) regarding human antibodies generated via a human B-cell hybridoma technology. See also KM Mouse® system, described in PCT Publication WO 02/43478 by Ishida et al., in which the mouse carries a human heavy chain transchromosome and a human light chain transgene, and the TC mouse system, described in Tomizuka et al. (2000) Proc. Natl. Acad. Sci. USA 97:722-727, in which the mouse carries both a human heavy chain transchromosome and a human light chain transchromosome, both of which are hereby incorporated by reference in their entireties. In each of these systems, the transgenes and/or transchromosomes carried by the mice comprise human immunoglobulin variable and constant region sequences. The term “human antibody”, as used herein, is intended to include antibodies having variable regions in which both the framework and CDR regions are sequences of human origin or identical thereto other than antibodies naturally occurring in a human or made in a human. Furthermore, if the antibody (e.g., an intact antibody rather than, for example, a Fab fragment) contains a constant region, the constant region also is derived from such human sequences, e.g., human germline sequences, or mutated versions of human germline sequences. The human antibodies disclosed herein may include amino acid residues not encoded by human sequences (e.g., mutations introduced by random or site-specific mutagenesis in vitro or by somatic mutation in vivo). In one non-limiting embodiment, where the human antibodies are human monoclonal antibodies, such antibodies can be produced by a hybridoma which includes a B cell obtained from a transgenic nonhuman animal, e.g., a transgenic mouse, having a genome comprising a human heavy chain transgene and a light chain transgene fused to an immortalized cell.
In embodiments, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, has a human framework region. In embodiments, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, comprises (i) a VH framework comprising the framework sequence of germline VH3-23*01 and/or (ii) a VK framework comprising the framework sequence of human germline 2-24*01. In embodiments, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, comprises (i) a VH framework comprising the framework sequence of human germline VH 4-59*08; and/or (ii) a VL framework comprising the framework sequence of human germline VL 1-51*02.
In embodiments, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, is a recombinant antibody. The term “recombinant human antibody”, as used herein, includes all human antibodies that are prepared, expressed, created or isolated by recombinant means, such as antibodies isolated from an animal (e.g., a mouse) that is transgenic or transchromosomal for human immunoglobulin genes or a hybridoma prepared therefrom, antibodies isolated from a host cell transformed to express the human antibody, e.g., from a transfectoma, antibodies isolated from a recombinant, combinatorial human antibody library, and antibodies prepared, expressed, created, or isolated by any other means that involve splicing of all or a portion of a human immunoglobulin gene sequences to other DNA sequences. Such recombinant human antibodies have variable regions in which the framework and CDR regions are derived from human germline immunoglobulin sequences. In certain embodiments, however, such recombinant human antibodies can be subjected to in vitro mutagenesis (or, when an animal transgenic for human Ig sequences is used, in vivo somatic mutagenesis) and thus the amino acid sequences of the VH and VL regions of the recombinant antibodies are sequences that, while derived from and related to human germline VH and VL sequences, may not naturally exist within the human antibody germline repertoire in vivo.
In some embodiments, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof is isolated. As used herein, the term “isolated antibody” refers to an antibody that by virtue of its origin or source of derivation meets one, two, three or four of the following criteria: (1) is not substantially associated with naturally associated components that accompany it in its native state, (2) is substantially free of other proteins from the same species, (3) is expressed by a cell from a different species, and (4) does not occur in nature.
In embodiments, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, comprises a human constant region or modified constant region. In some embodiments, the anti-Mtb AM antibody or Mtb AM-binding fragment thereof has a non-human constant region or a modified non-human constant region. In one embodiment, the anti-Mtb AM antibody or Mtb AM-binding fragment thereof has murine constant region or modified murine constant region. In one embodiment, the anti-Mtb AM antibody or Mtb AM-binding fragment thereof has a non-human primate constant region or modified non-human primate constant region. In some embodiments, the anti-Mtb AM antibody or Mtb AM-binding fragment thereof has a non-human constant region or a modified non-human constant region. In some embodiments, constant region is from a non-human primate, a mouse, a rat, a sheep, a goat, or a rabbit.
In embodiments, the antibody comprises an Fe domain. The term “Fc region” herein is used to define a C-terminal region of an immunoglobulin heavy chain, including native sequence Fc regions and variant Fc regions. Although the boundaries of the Fc region of an immunoglobulin heavy chain might vary, the human IgG heavy chain Fc region is usually defined to stretch from an amino acid residue at position Cys226, or from Pro230, to the carboxyl-terminus thereof. The C-terminal lysine of the Fc region may be removed, for example, during production or purification of the antibody, or by recombinantly engineering the nucleic acid encoding a heavy chain of the antibody. Accordingly, an intact antibody as used herein may be an antibody with or without the otherwise C-terminal lysine.
Depending on the amino acid sequences of the constant domains of their heavy chains, antibodies (immunoglobulins) can be assigned to different classes. The antibody or antigen-binding fragment can be, e.g., any of an IgG, IgD, IgE, IgA or IgM antibody or fragment thereof, respectively. In an embodiment the antibody is an immunoglobulin G. In an embodiment the antibody fragment is a fragment of an immunoglobulin G. In an embodiment the antibody is an IgG1, IgG2, IgG2a, IgG2b, IgG3 or IgG4. In an embodiment the antibody comprises sequences from a human IgG1, human IgG2, human IgG3 or human IgG4. A combination of any of these antibodies subtypes can also be used. One consideration in selecting the type of antibody to be used is the desired serum half-life of the antibody. For example, an IgG generally has a serum half-life of 23 days, IgA 6 days, IgM 5 days, IgD 3 days, and IgE 2 days. (Abbas A K, Lichtman A H, Pober J S. Cellular and Molecular Immunology, 4th edition, W.B. Saunders Co., Philadelphia, 2000, hereby incorporated by reference in its entirety).
In an embodiment, anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, comprises an Fe domain that has the same sequence or 99% or greater sequence similarity with a human IgG1 Fc domain. In an embodiment, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, comprises an Fe domain that has the same sequence or 99% or greater sequence similarity with a human IgG2 Fc domain. In an embodiment, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, comprises an Fc domain that has the same sequence or 99% or greater sequence similarity with a human IgG3 Fc domain. In an embodiment, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, comprises an Fc domain that has the same sequence or 99% or greater sequence similarity with a human IgG4 Fc domain. In an embodiment, the Fc domain is not mutated.
In an embodiment, the Fc domain is mutated at the CH2-CH3 domain interface to increase the affinity of IgG for FcRn at acidic but not neutral pH. In an embodiment, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, comprises an Fc domain that has the same sequence as a human IgG1 Fe domain.
In some embodiment, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, has a modified IgG Fc region. Modified IgG Fc regions are well known in the art. For example, see any of the mutations listed in Table 1 of Wang et al. Protein Cell (2018), 9(1):63-73. In embodiments, the modified Fc region, relative to the unmodified Fc region, has enhanced complement-based effector function, increased or decreased FcγR-based effector function, reduced effector function, enhanced coengagement of antigen and FcγRs, and/or increased serum half-life.
Non-limiting examples of Fc modifications to modulate antibody effector function for IgG1 (see Wang et al. Protein Cell (2018), 9(1):63-73) include are:
In embodiments, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, binds Mtb AM with a binding affinity (KD) of from about 1×10−6 M to about 1×10−10 M, from about 1×10−7 M to about 1×10−10 M, from about 1×10−8 M to about 1×10−10 M, from about 1×10−8 M to about 1×10−1 M. In embodiments, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, binds Mtb AM with a binding affinity (KD) of about 1×10−7 M, about 1×10−8 M, about 1×10−9 M, or about 1×10−10 M.
The term “KD”, as used herein, is intended to refer to the dissociation constant of an antibody-antigen interaction. One way of determining the KD or binding affinity of antibodies to Mtb capsular AM is by measuring binding affinity Using a Dip and Read assay using an immobilized antigen and monoclonal antibodies (Octet Red96 ForteBio, Fremont, CA). (The affinity constant is the inverted dissociation constant). Biotinylated Mtb capsular AM can be diluted into PBS+0.1% BSA, 0.02% Tween20 and 0.05% sodium azide (Kinetics Buffer, ForteBio) and dipped into wells containing serial diluted mAbs starting from 37.75 nM. The concentrations of the Fab proteins are determined by ELISA and/or SDS-PAGE electrophoresis using an IgG1 standard monoclonal antibody of known concentration as a standard. Kinetic association rates (kon) and dissociation rates (koff) are obtained simultaneously by fitting the data to a 1:1 Langmuir binding model (Karlsson, R. Roos, H. Fagerstam, L. Petersson, B. (1994). Methods Enzymology 6. 99-110, the content of which is hereby incorporated in its entirety) using the BIA evaluation program. Equilibrium dissociation constant (KD) values are calculated as koff/kon. This protocol is suitable for use in determining binding affinity of an antibody or fragment to any Mtb capsular AM. Other protocols known in the art may also be used. For example, ELISA of Mtb capsular AM with mAb can be used to determine the KD values.
In an embodiment, the Mtb capsular AM antibody described herein is capable of specifically binding or specifically binds an Mtb capsular AM. As used herein, the terms “is capable of specifically binding” or “specifically binds” refers to the property of an antibody or fragment of binding to the specified antigen with a dissociation constant that is <1 μM, preferably <1 nM and most preferably <10 μM. In an embodiment, the KD of the antibody (or antigen-binding fragment thereof) for Mtb capsular AM is less than 100 nM. In an embodiment, the KD of the antibody (or antigen-binding fragment thereof) for Mtb capsular AM is less than 10 nM. In an embodiment, the KD of the antibody (or antigen-binding fragment thereof) for Mtb capsular AM is less than 1.0 nM. In an embodiment, the KD of the antibody (or fragment) for avirulent Mtb capsular AM is a lower affinity than its KD for virulent Mtb capsular AM. An epitope that “specifically binds” to an antibody or a polypeptide is a term well understood in the art. A molecular entity is said to exhibit “specific binding” or “preferential binding” if it reacts or associates more frequently, more rapidly, with greater duration and/or with greater affinity with a particular cell or substance than it does with alternative cells or substances. An antibody “specifically binds” or “preferentially binds” to a target if it binds with greater affinity, avidity, more readily, and/or with greater duration than it binds to other substances. For example, an antibody that specifically or preferentially binds to an Mtb capsular AM conformational epitope is an antibody that binds this epitope with greater affinity, avidity, more readily, and/or with greater duration than it binds to other Mtb capsular AM epitopes or non-Mtb capsular AM epitopes. It is also understood by reading this definition that, for example, an antibody (or moiety or epitope) that specifically or preferentially binds to a first target may or may not specifically or preferentially bind to a second target. As such, “specific binding” or “preferential binding” does not necessarily require, although it can include, exclusive binding.
In embodiments, the antibody, or antigen-binding fragment thereof, binds to a linear epitope. In embodiments, the antibody, or antigen-binding fragment thereof, binds to a linear oligosaccharide epitope.
In one embodiment, an anti-Mtb AM antibody or Mtb AM-binding fragment thereof disclosed herein binds to its antigen with one, two, three four, five, or six CDRs.
The term “compete”, as used herein with regard to an antibody, means that a first antibody, or an antigen-binding portion thereof, binds to an epitope in a manner sufficiently similar to the binding of a second antibody, or an antigen-binding portion thereof, such that the result of binding of the first antibody with its cognate epitope is detectably decreased in the presence of the second antibody compared to the binding of the first antibody in the absence of the second antibody. The alternative, where the binding of the second antibody to its epitope is also detectably decreased in the presence of the first antibody, can, but need not be the case. That is, a first antibody can inhibit the binding of a second antibody to its epitope without that second antibody inhibiting the binding of the first antibody to its respective epitope. However, where each antibody detectably inhibits the binding of the other antibody with its cognate epitope or ligand, whether to the same, greater, or lesser extent, the antibodies are said to “cross-compete” with each other for binding of their respective epitope(s). Both competing and cross-competing antibodies are disclosed herein. Regardless of the mechanism by which such competition or cross-competition occurs (e.g., steric hindrance, conformational change, or binding to a common epitope, or portion thereof), the skilled artisan would appreciate, based upon the teachings provided herein, that such competing and/or cross-competing antibodies are encompassed and can be useful for the methods disclosed herein.
As used herein, the term “antigen-binding portion” or “antigen-binding fragment” may be a fragment comprising a Fab, Fab′, F(ab′)2, Fd, Fv, domain antibodies (dAbs such as shark and camel antibodies), ScFv, a maxibody, a minibody, a nanobody, an intrabody, a diabody, a triabody, a tetrabody, a v-NAR and a bis-scFv, or a polypeptide that contain at least certain portions of an immunoglobulin sufficient to confer specific antigen-binding to the polypeptide.
Antibody fragments can be prepared, for example, by cleaving an intact antibody or by recombinant means. See generally, Fundamental Immunology, Ch. 7 (Paul, W., ed., 2nd ed. Raven Press, N.Y. (1989), hereby incorporated by reference in its entirety). Antigen-binding fragments may be produced by recombinant DNA techniques or by enzymatic or chemical cleavage of intact antibodies or by molecular biology techniques.
The antibody may be any class of antibody, such as IgG, IgA, or IgM (or a subclass thereof), and the antibody need not be of any particular class, and any of the immunoglobulin molecules comprising the antigen recognition site of the required specificity, other modified configurations (including glycosylation variants of antibodies, amino acid sequence variants of antibodies, and covalently modified antibodies) can be encompassed. Modified versions of each of these classes and isotypes are known to a person skilled in the art, accordingly, are within the scope of the instant disclosure.
In some embodiments of the aspects described herein, the anti-Mtb AM antibody disclosed herein is a Fab fragment, which comprises or consist essentially of a variable (VL) and constant (CL) domain of the light chain and a variable domain (VH) and the first constant domain (CH1) of the heavy chain.
In some embodiments of the aspects described herein, the anti-Mtb AM antibody fragment is a Fab′ fragment, which refers to a Fab fragment having one or more cysteine residues at the C-terminus of the CH1 domain.
In some embodiments of the aspects described herein, the anti-Mtb AM antibody fragment is an Fd fragment comprising or consisting essentially of VH and CH1 domains.
In some embodiments of the aspects described herein, the anti-Mtb AM antibody fragment is an Fd′ fragment comprising VH and CH domains and one or more cysteine residues at the C-terminus of the CH1 domain.
Single-chain Fv or scFv antibody fragments comprise or consist essentially of the VH and VL domains of an antibody, such that these domains are present in a single polypeptide chain. Generally, an Fv polypeptide further comprises a polypeptide linker between the VH and VL domains, which allows the scFv to form the desired structure for antigen-binding. Accordingly, in some embodiments of the aspects described herein, the anti-Mtb AM antibody fragment is a Fv fragment comprising or consisting essentially of the VL and VH domains of a single arm of an antibody.
In some embodiments of the aspects described herein, the anti-Mtb AM antibody fragment is a diabody comprising two antigen-binding sites, comprising a heavy chain variable domain (VH) connected to a light chain variable domain (VL) in the same polypeptide chain.
In some embodiments of the aspects described herein, the anti-Mtb AM antibody fragment is a dAb fragment comprising or consisting essentially of a VH domain.
In some embodiments of the aspects described herein, the anti-Mtb AM antibody fragment is a F(ab′)2 fragment, which comprises a bivalent fragment comprising two Fab′ fragments linked by a disulfide bridge at the hinge region.
In some embodiments of the aspects described herein, the anti-Mtb AM antibody fragment is a linear antibody comprising a pair of tandem Fd segments (VH-CH1-VH-CH1) which, together with complementary light chain polypeptides, form a pair of antigen-binding regions.
A person skilled in the arts can use various techniques that have been developed and are available for the production of antibody fragments. Traditionally, these fragments were derived via proteolytic digestion of intact antibodies. However, F(ab′)2 fragments can be isolated directly from recombinant host cell culture. Other techniques for the production of antibody fragments will be apparent to the skilled practitioner. In other embodiments, the antibody fragment of choice is a single chain Fv fragment (scFv). See, for example, WO 93/16185. Alternatively, these fragments can also be produced directly by recombinant host cells. For example, antibody fragments can be isolated from the antibody phage libraries discussed herein. In another approach, Fab′-SH fragments can be directly recovered from E. coli and chemically coupled to form F(ab′)2 fragments (Carter et al., 1992).
Contemplated antibodies or antigen-binding fragments may have all types of constant regions, including IgM, IgG, IgD, and IgE, and any isotype, including IgG1, IgG2, IgG3, and IgG4. In one embodiment, the isotype is human IgG1. In another embodiment, the human isotype IgG4 is used. Light chain constant regions can be λ or κ. The antibody, or antigen-binding fragment thereof, may comprise sequences from more than one class or isotype.
In some embodiments, the anti-Mtb AM antibody, or antigen-binding fragment thereof, may include a modification, including, but not limited to glycosylation, acetylation, pegylation, phosphorylation, phosphorylation, amidation, derivatization by known protecting/blocking groups, proteolytic cleavage, linkage to a cellular ligand or other protein, etc. The process of making chemical modifications is known in the art, and may include, but are not limited to, specific chemical cleavage, acetylation, formylation, metabolic synthesis of tunicamycin, etc. Additionally, the molecules may contain one or more non-classical amino acids.
In some embodiments of the aspects described herein, the anti-Mtb AM antibody, or antigen-binding fragment thereof, is conjugated to a functional moiety. Examples of useful functional moieties include, but are not limited to, a blocking moiety, a detectable moiety, a diagnostic moiety, a targeting moiety, and a therapeutic moiety.
Exemplary blocking moieties include moieties of sufficient steric bulk and/or charge such that reduced glycosylation occurs, for example, by blocking the ability of a glycosidase to glycosylate the antibody or antigen-binding fragment thereof. The blocking moiety may, additionally or alternatively, reduce effector function, for example, by inhibiting the ability of the Fc region to bind a receptor or complement protein. Preferred blocking moieties include cysteine adducts and PEG moieties.
In one embodiment, the blocking moiety is a cysteine, preferably a cysteine that has associated with a free cysteine, e.g., during or subsequent to the translation of the Fc containing polypeptide, e.g., in cell culture. Other blocking cysteine adducts include cystine, mixed disulfide adducts, or disulfide linkages.
In another embodiment, the blocking moiety is a polyalkylene glycol moiety, for example, a PEG moiety and preferably a PEG-maleimide moiety. Preferred pegylation moieties (or related polymers) can be, for example, polyethylene glycol (“PEG”), polypropylene glycol (“PPG”), polyoxyethylated glycerol (“POG”) and other polyoxyethylated polyols, polyvinyl alcohol (“PVA”) and other polyalkylene oxides, polyoxyethylated sorbitol, or polyoxyethylated glu-cose. The polymer can be a homopolymer, a random or block copolymer, a terpolymer based on the monomers listed above, straight chain or branched, substituted or unsubstituted as long as it has at least one active sulfone moiety. The polymeric portion can be of any length or molecular weight but these characteristics can affect the biological properties. Polymer average molecular weights particularly useful for decreasing clearance rates in pharmaceutical applications are in the range of 2,000 to 35,000 Daltons. In addition, if two groups are linked to the polymer, one at each end, the length of the polymer can impact upon the effective distance, and other spatial relationships, between the two groups. Thus, one skilled in the art can vary the length of the polymer to optimize or confer the desired biological activity. PEG is useful in biological applications for several reasons. PEG typically is clear, colorless, odorless, soluble in water, stable to heat, inert to many chemical agents, does not hydrolyze, and is nontoxic. Pegylation can im-prove pharmacokinetic performance of a molecule by increasing the molecule's apparent molecular weight. The increased apparent molecular weight reduces the rate of clearance from the body following subcutaneous or systemic administration. In many cases, pegylation can de-crease antigenicity and immunogenicity. In addition, pegylation can increase the solubility of a biologically-active molecule.
Examples of detectable moieties for the detection of the anti-Mtb AM antibodies and Mtb AM-binding fragments thereof contemplated by the disclosure include fluorescent moieties or labels, imaging agents, radioisotopic moieties, radiopaque moieties, and the like, e.g. detectable labels such as biotin, fluorophores, chromophores, spin resonance probes, or radiolabels. Exemplary fluorophores include fluorescent dyes (e.g. fluorescein, rhodamine, and the like) and other luminescent molecules (e.g. luminol). A fluorophore may be environmentally-sensitive such that its fluorescence changes if it is located close to one or more residues in the modified protein that undergo structural changes upon binding a substrate (e.g. dansyl probes). Exemplary radiolabels include small molecules containing atoms with one or more low sensitivity nuclei (13C, 15N, 2H, 125I, 123I, 99Tc, 43K, 52Fe, 67Ga 68Ga, 111In and the like). Other useful moieties are known in the art.
Examples of therapeutic moieties include anti-tuberculosis agents. Anti-tuberculosis agents include, but are not limited to, ethambutol, pyrazinamide, streptomycin, isoniazid, moxifloxacin rifampicin, levofloxacin, moxifloxacin, clofazimine, bedaquiline, cycloserine, terizidone, delamanid, linezolid, pyrazinamide, imipenem-cilastatin (Ipm-Cln) or Meropenem, amikacin, streptomycin, ethionamide, Prothionamide, and p-aminosalicylic acid.
The functional moiety may also have one or more of the above-mentioned functions.
To increase the half-life of the antibodies or polypeptides containing the amino acid sequences described herein, one can attach a salvage receptor binding epitope to the anti-Mtb AM antibody or Mtb AM-binding fragment thereof (especially an antibody fragment), as described, e.g., in U.S. Pat. No. 5,739,277. The term “salvage receptor binding epitope” may refer to an epitope of the Fc region of an IgG molecule (e.g., IgG1, IgG2, IgG3, or IgG4) that is responsible for in-creasing the in vivo serum half-life of the IgG molecule (e.g., Ghetie et al., 18 Ann. Rev. Immunol. 739 (2000). Antibodies with substitutions in an Fc region thereof and increased serum half-lives are also described in WO 00/42072, WO 02/060919; Shields et al., 276 J. Biol. Chem. 6591 (2001); Hinton, 279 J. Biol. Chem. 6213-6216 (2004). For example, a nucleic acid molecule encoding the salvage receptor binding epitope can be linked in frame to a nucleic acid encoding a polypeptide sequence described herein so that the fusion protein expressed by the engineered nucleic acid molecule comprises the salvage receptor binding epitope and a polypeptide sequence described herein. In another embodiment, the serum half-life can also be in-creased, for example, by attaching other polypeptide sequences.
Other types of functional moieties are known in the art and can be readily used in the methods and compositions of the present disclosure based on the teachings contained herein.
Also provided herein are nucleic acids encoding the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, as well as vectors, host cells, and expression systems. The term “nucleic acid” as used herein refers to a polymeric form of nucleotides of any length, either ribonucleotides or desoxyribonucleotides. Thus, this term includes, but is not limited to, single-double- or multi-stranded DNA or RNA, genomic DNA, cDNA, DNA-RNA hybrids, or a polymer comprising purine and pyrimidine bases, or other natural, chemically or biochemically modified, non-natural, or derivatized nucleotide bases.
In some embodiments, provided is a nucleic acid sequence comprising a sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:9. In some embodiments, provided is a nucleic acid sequence comprising a sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:10. In some embodiments, provided is a nucleic acid sequence comprising a sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:9 and a sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:10.
In some embodiments, provided is a nucleic acid sequence comprising a sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:33. In some embodiments, provided is a nucleic acid sequence comprising a sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:35. In some embodiments, provided is a nucleic acid sequence comprising a sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:33 and a sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:35.
In one embodiment, a nucleic acid provided herein encoding an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof is codon-optimized.
The nucleic acids encoding the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, may be, e.g., DNA, cDNA, RNA, synthetically produced DNA or RNA, or a recombinantly produced chimeric nucleic acid molecule comprising any of those polynucleotides either alone or in combination. For example, provided is an expression vector or set of expression vectors comprising a polynucleotide sequence encoding an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, described herein operably linked to expression control sequences suitable for expression in a eukaryotic and/or prokaryotic host cell.
The term “vector” refers to a nucleic acid molecule capable of transporting another nucleic acid to which it has been linked. A “vector” includes, but is not limited to, a viral vector, a plasmid, an RNA vector or a linear or circular DNA or RNA molecule which may consists of a chromosomal, non-chromosomal, semi-synthetic or synthetic nucleic acids. In some embodiments, the employed vectors are those capable of autonomous replication (episomal vector) and/or expression of nucleic acids to which they are linked (expression vectors). Large numbers of suitable vectors are known to those of skill in the art and commercially available. Viral vectors include retrovirus, adenovirus, parvovirus (e.g., adeno associated viruses, AAV), coronavirus, negative strand RNA viruses such as orthomyxovirus (e.g., influenza virus), rhabdovirus (e. g., rabies and vesicular stomatitis virus), paramyxovirus (e.g., measles and Sendai), positive strand RNA viruses such as picornavirus and alphavirus, and double-stranded DNA viruses including adenovirus, herpesvirus (e.g., Herpes Simplex virus types 1 and 2, Epstein-Barr virus, cytomegalovirus), and poxvirus (e.g., vaccinia, fowlpox and canarypox). Other viruses include Norwalk virus, togavirus, flavivirus, reoviruses, papovavirus, hepadnavirus, and hepatitis virus, for example. Examples of retroviruses include: avian leukosis-sarcoma, mammalian C-type, B-type viruses, D type viruses, HTLV-BLV group, lentivirus, and spumavirus.
n some embodiments, provided is a vector comprising a nucleic acid sequence comprising a sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:9. In some embodiments, provided is a vector comprising a nucleic acid sequence comprising a sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:10. In some embodiments, provided is a vector or a set of vectors comprising (1) a nucleic acid sequence comprising a sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:9 and (2) a nucleic acid sequence comprising a sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:10. In some embodiments, provided is a vector or a set of vectors comprising SEQ ID NO:9 and SEQ ID NO:10.
In some embodiments, provided is a vector comprising a nucleic acid sequence comprising a sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:33. In some embodiments, provided is a vector comprising a nucleic acid sequence comprising a sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:35. In some embodiments, provided is a vector or a set of vectors comprising (1) a nucleic acid sequence comprising a sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:33 and (2) a nucleic acid sequence comprising a sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:35. In some embodiments, provided is a vector or a set of vectors comprising SEQ ID NO:33 and SEQ ID NO:35.
A variety of expression vectors have been developed for the efficient synthesis of the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, in prokaryotic cells such as bacteria and in eukaryotic systems, including but not limited to yeast and mammalian cell culture systems have been developed. The vectors can comprise segments of chromosomal, non-chromosomal and synthetic DNA sequences. Also provided are cells comprising expression vectors for the expression of the disclosed the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof.
In an embodiment, a host cell comprising a nucleic acid molecule described herein, or a vector described herein, is provided.
In an embodiment, provided is a method of producing an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein comprising culturing a cell comprising one or more nucleic acid molecules encoding for an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein under conditions whereby the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, is produced by the host cell.
Provided herein is a method of making an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein, the method comprising:
Provided herein is a method of making an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein, the method comprising:
Provided herein is a method of making an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein, the method comprising:
Provided herein is a method of making an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein, the method comprising:
Provided herein is a method of making an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein, the method comprising:
Provided herein is a method of making an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein, the method comprising:
Provided herein is a method of making an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein, the method comprising:
The anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, disclosed herein are typically produced by recombinant expression. Nucleic acids encoding light and heavy chain variable regions, optionally linked to constant regions, may be inserted into the same expression vectors. Alternatively, the nucleic acids encoding light and heavy chain variable regions, optionally linked to constant regions, are inserted into different expression vectors. The expression vector may further comprise one or more expression control sequences, which include, but are not limited to, promoters (e.g., homologous or heterologous promoters), signal sequences, enhancer elements, and transcription termination sequences. Preferably, the expression control sequences are eukaryotic promoter systems in vectors capable of transforming or transfecting eukaryotic host cells. Typically, the host is maintained under conditions suitable for high-level expression of the nucleotide sequences, and the collection and purification of the cross-reacting antibodies after the vector is incorporated into the appropriate host.
Commonly, expression vectors contain selection markers (e.g., ampicillin-resistance, hygromycin-resistance, tetracycline resistance or neomycin resistance) to permit detection of those cells transformed with the desired DNA sequences.
The host used to express the anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, disclosed herein can be a prokaryotic or eukaryotic host. Examples of suitable hosts include bacterial or eukaryotic hosts, including yeast, insects, fungi, bird and mammalian cells either in vivo, or in situ, or host cells of mammalian, insect, bird, or yeast origin. The mammalian cell or tissue can be of human, primate, hamster, rabbit, rodent, cow, pig, sheep, horse, goat, dog, or cat origin, but any other mammalian cell may be used.
Examples of bacterial hosts that can be used to express the antibodies, antigen-binding fragments or the fusion protein disclosed herein can be E. coli, bacilli, such as Bacillus subtilis, and other enterobacteriaceae, such as Salmonella, Serratia, and various Pseudomonas species.
Yeasts may also be used as hosts for expressing the express the antibodies, antigen-binding fragments or the fusion protein disclosed herein. Saccharomyces and Pichia are exemplary yeast hosts, with suitable vectors having expression control sequences (e.g., promoters), an origin of replication, termination sequences, and the like as desired. Typical promoters include 3-phosphoglycerate kinase and other glycolytic enzymes. Inducible yeast promoters include, among others, promoters from alcohol dehydrogenase, isocytochrome C, and enzymes responsible for methanol, maltose, and galactose utilization.
Mammalian cells in culture may also be used as host cells for expressing the antibodies, antigen-binding fragments or the fusion proteins disclosed herein. Examples of suitable host cell lines capable of secreting heterologous proteins (e.g., intact immunoglobulins) which are well known in the art, include CHO cell lines, various COS cell lines, HeLa cells, 293 cells, myeloma cell lines, transformed B-cells, and hybridomas. Expression vectors for these cells can include expression control sequences, such as an origin of replication, a promoter, an enhancer and necessary processing information sites such as ribosome binding site, RNA splice site and/or transcriptional terminator sequences. Examples of expression control sequences include SV40, adenovirus, bovine papilloma virus, cytomegalovirus and the like.
The anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, disclosed herein can be expressed using a single expression construct or vector or multiple expression constructs or vectors (e.g., two or three expression constructs). When the antibody heavy and light chains are cloned on separate expression vectors, the vectors are co-transfected to obtain expression and assembly of intact immunoglobulins. Once expressed, the whole antibodies, their dimers, individual light and heavy chains, or other immunoglobulin forms disclosed herein can be purified according to standard procedures of the art, including ammonium sulfate precipitation, affinity columns, column chromatography, HPLC purification, gel electrophoresis, and the like (see generally Scopes, Protein Purification (Springer-Verlag, N.Y., (1982)). Substantially pure immunoglobulins of at least about 90 to 95% homogeneity are preferred, and 98 to 99% or more homogeneity most preferred, for pharmaceutical uses.
The anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, disclosed herein can be made by any method known in the art.
In an embodiment, a pharmaceutical composition is provided comprising an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof as described herein.
In an embodiment, a pharmaceutical composition comprising an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, described herein, and a pharmaceutically acceptable excipient, is provided. The pharmaceutically acceptable excipient can be a pharmaceutically-acceptable material, composition or vehicle, such as a liquid or solid filler, diluent, manufacturing aid (e.g., lubricant, talc magnesium, calcium or zinc stearate, or steric acid), solvent or encapsulating material, involved in carrying or transporting the therapeutic compound for administration to the subject, bulking agent, salt, surfactant and/or a preservative. Some examples of materials which can serve as pharmaceutically-acceptable excipients include: sugars, such as lactose, glucose and sucrose; starches, such as corn starch and potato starch; cellulose and its derivatives, such as sodium carboxymethyl cellulose, ethyl cellulose and cellulose acetate; gelatin; talc; waxes; oils, such as peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil and soybean oil; glycols, such as ethylene glycol and propylene glycol; polyols, such as glycerin, sorbitol, mannitol and polyethylene glycol; esters, such as ethyl oleate and ethyl laurate; agar; buffering agents; water; isotonic saline; pH buffered solutions; and other non-toxic compatible substances employed in pharmaceutical formulations.
Compositions or pharmaceutical compositions comprising the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein comprise stabilizers to prevent loss of activity or structural integrity of the protein due to the effects of denaturation, oxidation, or aggregation over a period of time during storage and transportation prior to use. The compositions or pharmaceutical compositions can comprise one or more of any combination of salts, surfactants, pH and tonicity agents such as sugars that contribute to overcoming aggregation problems. Where a composition or pharmaceutical composition disclosed herein is used as an injection, the composition may have a pH value in an approximately neutral pH range. In some embodiments, surfactant levels are minimized to avoid bubbles in the formulation which are detrimental for injection into subjects. In an embodiment, the composition or pharmaceutical composition is in liquid form and stably supports high concentrations of bioactive antibody in solution and is suitable for inhalational or parenteral administration. In an embodiment, the composition or pharmaceutical composition is suitable for intravenous, intramuscular, intraperitoneal, intradermal and/or subcutaneous injection. In an embodiment, the composition or pharmaceutical composition is in liquid form and has minimized risk of bubble formation and a naphylactoid side effects. In an embodiment, the composition or pharmaceutical composition is isotonic. In an embodiment, the composition or pharmaceutical composition has a pH or 6.8 to 7.4.
In one embodiment, the anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein is lyophilized and/or freeze dried and is reconstituted for use.
The antibodies, or fragments of antibodies, or compositions, or pharmaceutical compositions described herein can also be lyophilized or provided in any suitable forms including, but not limited to, injectable solutions or inhalable solutions, gel forms, and tablet forms.
Provided herein is a method of reducing the activity of Mtb AM in a subject in need thereof, the method comprising administering to said subject a therapeutically effective amount of (1) an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein or (2) a pharmaceutical composition comprising an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein. Provided herein is (1) an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein or (2) a pharmaceutical composition comprising an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, for use in reducing the activity of Mtb AM in a subject in need thereof. Provided herein is the use of an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein in the manufacture of a medicament for reducing the activity of Mtb AM in a subject in need thereof.
Provided herein is a method of treating a Mycobacterium tuberculosis infection in a subject in need thereof, the method comprising administering to said subject a therapeutically effective amount of (1) an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein or (2) a pharmaceutical composition comprising an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein. Provided herein is (1) an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein or (2) a pharmaceutical composition comprising an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, for use in treating a Mycobacterium tuberculosis infection in a subject in need thereof. Provided herein is the use of an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein in the manufacture of a medicament for treating a Mycobacterium tuberculosis infection in a subject in need thereof.
In an embodiment, the disclosure provides a method of reducing the likelihood of a Mycobacterium tuberculosis infection in a subject in need thereof, the method comprising administering to the subject who does not have a Mycobacterium tuberculosis infection a prophylactically effective amount of (1) an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein or (2) a pharmaceutical composition comprising an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein. Provided herein is (1) an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein or (2) a pharmaceutical composition comprising an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, for use in reducing the likelihood of a Mycobacterium tuberculosis infection in a subject in need thereof. Provided herein is the use of an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein in the manufacture of a medicament for reducing the likelihood of a Mycobacterium tuberculosis infection in a subject in need thereof.
In an embodiment, the disclosure provides a method of treating a disease, disorder, or condition mediated by, or related to increased activity of Mycobacterium tuberculosis in a subject in need thereof, the method comprising administering to said subject a therapeutically effective amount of (1) an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein or (2) a pharmaceutical composition comprising an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein. Provided herein is (1) an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein or (2) a pharmaceutical composition comprising an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, for use in treating a disease, disorder, or condition mediated by, or related to increased activity of Mycobacterium tuberculosis in a subject in need thereof. Provided herein is the use of an anti-Mtb AM antibody, or Mtb AM-binding fragment thereof, disclosed herein in the manufacture of a medicament for treating a disease, disorder, or condition mediated by, or related to increased activity of Mycobacterium tuberculosis in a subject in need thereof.
In embodiments, the “subject” is a mammal. In embodiment, the subject is a non-primate (e.g., cows, pigs, horses, cats, dogs, rats, mouse, etc.) or a primate (e.g., monkey and human). Individuals and patients are also subjects herein.
The anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, disclosed herein can be administered with to one or more additional therapeutic agents. Suitable additional therapeutic agents in this regard include, but are not limited to, drugs, toxins, and derivatives thereof. Non-limiting examples of additional therapeutic agents include isoniazid, rifampin, ethambutol, pyrazinamide, bedaquiline, linezolid, and pretomanid.
In an embodiment, an assay device is provided for selectively detecting a one or more bacteria from the MTC group in a biological sample comprising: a first portion comprising a first plurality of anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, as described herein, or anti-mycobacterial AM-antibodies, wherein the antibodies or fragments are each attached to their own reporting entity; and a second portion comprising a second plurality of anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, as described herein, or anti-mycobacterial AM-antibodies.
In an embodiment, an assay device is provided for selectively detecting AM and/or LAM in a biological sample comprising: a first portion comprising a first plurality of anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, as described herein, or anti-mycobacterial AM-antibodies, wherein the antibodies or fragments are each attached to their own reporting entity; and a second portion comprising a second plurality of anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, as described herein, or anti-mycobacterial AM-antibodies.
In an embodiment, an assay device is provided for selectively detecting AM and/or LAM from MTC in a biological sample comprising: a first portion comprising a first plurality of anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, as described herein, or anti-mycobacterial AM-antibodies, wherein the antibodies or fragments are each attached to their own reporting entity; and a second portion comprising a second plurality of anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, as described herein, or anti-mycobacterial AM-antibodies.
MTC is a genetically related group of Mycobacterium species that can cause tuberculosis in humans or other animals and includes Mycobacterium tuberculosis, M. africanum, M. canettii, M. bovis, M. microti, M. orygis, M. caprae, M. pinnipedii, M. suricattae, and M. mungi.
In an embodiment, the reporting entity comprises an enzyme. In an embodiment, the enzyme is horseradish peroxidase (HRP) or alkaline phosphatase (AP).
In one embodiment, the reporting entity comprises a gold nanoparticle.
In embodiments, the second plurality of anti-Mtb AM-antibodies, or Mtb AM-binding fragments thereof, or anti-mycobacterial AM-antibodies, is affixed to a solid support of the device.
In embodiments, the first plurality of anti-Mtb AM-antibodies, or Mtb AM-binding fragments thereof, or anti-mycobacterial AM-antibodies, is not affixed to a solid support of the device.
In embodiments, the solid support comprises nitrocellulose.
In embodiments, the device further comprises a fluid sample pad prior in sequential order to the first and second portions.
In embodiments, the device further comprises a control portion subsequent in sequential order to the first and second portions.
In embodiments, the control portion comprises a third plurality of antibodies, immobilized on a solid support of the device, and which third plurality of antibodies are capable of binding the first plurality of anti-Mtb AM-antibodies, or Mtb AM-binding fragments thereof, or anti-mycobacterial AM-antibodies each attached to their own reporting molecule.
In embodiments, the device further comprises a fluid-absorbent wicking pad subsequent in sequential order to the first and second portions, and third portion if present.
In embodiments, the second plurality of anti-Mtb AM-antibodies, or Mtb AM-binding fragments thereof, as described herein, or anti-mycobacterial AM-antibodies.
Provided is a lateral flow assay device for detecting a Mycobacterium tuberculosis in a biological sample comprising:
Provided is a lateral flow assay device for detecting AM and/or LAM in a biological sample comprising:
In some embodiments, the first plurality of anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, comprises anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, comprising a heavy chain variable region and a light chain variable region, wherein the heavy chain and the light chain variable regions comprise a CDR1, CDR2, and CDR3; and wherein CDR1H comprises SEQ ID NO:1, CDR2H comprises SEQ ID NO:2, CDR3H comprises SEQ ID NO:3, CDR1L comprises SEQ ID NO:4, CDR2L comprises SEQ ID NO:5, and CDR3L comprises SEQ ID NO:6, In some embodiment, the first plurality of anti-Mtb AM-antibodies, or Mtb AM-binding fragments thereof, comprises anti-Mtb AM-antibodies, or Mtb AM-binding fragments thereof, comprising a heavy variable region comprising SEQ ID NO:7 and a light variable region comprising SEQ ID NO:8. In some embodiments, the first plurality of anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, comprises anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, comprising a heavy chain variable region and a light chain variable region, wherein the heavy chain and the light chain variable regions comprise a CDR1, CDR2, and CDR3; and wherein CDR1H comprises SEQ ID NO:26, CDR2H comprises SEQ ID NO:27, CDR3H comprises SEQ ID NO:28, CDR1L comprises SEQ ID NO:29, CDR2L comprises SEQ ID NO:30, and CDR3L comprises SEQ ID NO:31. In some embodiment, the first plurality of anti-Mtb AM-antibodies, or Mtb AM-binding fragments thereof, comprises anti-Mtb AM-antibodies, or Mtb AM-binding fragments thereof, comprising a heavy variable region comprising SEQ ID NO:32 and a light variable region comprising SEQ ID NO:34.
In some embodiments, the second plurality of anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, comprises anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, comprising a heavy chain variable region and a light chain variable region, wherein the heavy chain and the light chain variable regions comprise a CDR1, CDR2, and CDR3; and wherein CDR1H comprises SEQ ID NO:17, CDR2H comprises SEQ ID NO:18, CDR3H comprises SEQ ID NO:19, CDR1L comprises SEQ ID NO:20, CDR2L comprises SEQ ID NO:21, and CDR3L comprises SEQ ID NO:22. In some embodiments, the second plurality of anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, comprises anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, comprising a heavy chain variable region and a light chain variable region, wherein the heavy chain variable regions comprises a sequence comprising SEQ ID NO: 23 or SEQ ID NO: 24, and wherein the light chain variable region comprises a sequence comprising SEQ ID NO: 25.
In some embodiments, the assay device comprises one or more pluralities of anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, or anti-mycobacterial AM-antibodies, wherein at least one of the pluralities of anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, or anti-mycobacterial AM-antibodies, comprises a non-human constant region or a modified non-human constant region. In some embodiments, the assay device comprises one or more pluralities of anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, or anti-mycobacterial AM-antibodies, wherein at least one of the pluralities of anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, or anti-mycobacterial AM-antibodies, comprises a murine constant region or a modified murine constant region.
In an embodiment, the reporting entity comprises an enzyme. In an embodiment, the enzyme is horseradish peroxidase (HRP) or alkaline phosphatase (AP). In an embodiment, the reporting entity comprises a gold nanoparticle.
In an embodiment, the second plurality of anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, or anti-mycobacterial AM-antibodies is affixed to a solid support of the device.
In an embodiment, the first plurality of anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, or anti-mycobacterial AM-antibodies is not affixed to a solid support of the device.
In an embodiment, the solid support comprises nitrocellulose.
In an embodiment, the device further comprises a fluid sample pad prior in sequential order to the first and second portions.
In an embodiment, the device further comprises a control portion subsequent in sequential order to the first and second portions.
In an embodiment, the control portion comprises a third plurality of antibodies, immobilized on a solid support of the device, and which third plurality of antibodies are capable of binding the first plurality of anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, or anti-mycobacterial AM-antibodies, each attached to their own reporting molecule.
In an embodiment, the device further comprises a fluid-absorbent wicking pad subsequent in sequential order to the first and second portions, and third portion if present.
In embodiments, the second plurality of anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, comprises anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, described herein.
Provided herein is an assay device for selectively detecting one or more bacteria from the MTC group in a biological sample comprising:
Provided herein is an assay device for selectively detecting one or more bacteria from the MTC group in a biological sample comprising:
Provided herein is an assay device for selectively detecting one or more bacteria from the MTC group in a biological sample comprising:
Provided herein is an assay device for selectively detecting AM or LAM from the MTC group in a biological sample comprising:
Provided herein is an assay device for selectively detecting AM or LAM from the MTC group in a biological sample comprising:
Provided herein is an assay device for selectively detecting AM or LAM from the MTC group in a biological sample comprising:
In an embodiment, a method is provided for detecting one or more bacteria from the MTC group in a biological sample comprising:
Many available anti-Mtb AM antibodies react with mycobacterial strains from both the MTC group and non-tuberculous mycobacteria (NTM). In embodiments, provided herein are antibodies and antigen-binding fragments thereof that bind to MTC and show significantly decreased or no binding to NTM. Accordingly, provided is a method of discriminating between one or more bacteria from the MTC group and NTM using anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, or anti-mycobacterial AM-antibodies, including anti-Mtb AM antibodies, or Mtb AM-binding fragments thereof, disclosed herein. Diagnostic tests based on such methods that are able to discriminate between virulent and non-virulent Mycobacterium infections, or one or more bacteria from the MTC group and NTM, represent a major advance that will greatly reduce wasted effort and consequent costs resulting from further diagnostic tests and/or therapeutic procedures.
In one embodiment, provided is a method of detecting and/or distinguishing one or more bacteria from the MTC group and NTM in a biological sample, the method comprising:
In embodiments, the method further comprises obtaining the sample from a subject.
In embodiments, the sample is blood, blood plasma, blood serum, cerebrospinal fluid, bile acid, saliva, synovial fluid, pleural fluid, pericardial fluid, peritoneal fluid, feces, nasal fluid, ocular fluid, intracellular fluid, intercellular fluid, lymph fluid, urine, tissue, sputum, bladder washings, oral washings, tissue samples, touch preps, or fine-needle aspirates. The biological sample can be concentrated prior to use.
In embodiments, the subject is human. In some embodiment, the subject is a non-human mammal. In some embodiments, the subject is a cow, buffalo, lion. In some embodiment, the subject is an animal suitable for use in research, including, but not limited to, mouse, rat, rabbit, guinea pig, sheep, goat, and nonhuman primate. In some embodiments, the antibodies and antigen-binding fragments thereof disclosed herein bind to one or more strains of the MTC group, which comprises Mycobacterium tuberculosis, M. africanum, M. canettii, M. bovis, M. microti, M. orygis, M. caprae, M. pinnipedii, M. suricattae, and M. mungi. In some embodiments, the antibodies and antigen-binding fragments thereof disclosed herein bind to M. bovis.
“And/or” as used herein, for example, with option A and/or option B, encompasses the separate embodiments of (i) option A, (ii) option B, and (iii) option A plus option B.
All combinations of the various elements described herein are within the scope of the disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.
All references cited herein are incorporated herein in their entireties.
The following non-limiting example serves to further illustrate embodiments of the disclosure.
Material and Methods for the Examples below
Donor Information
Sera and peripheral blood mononuclear cells (PBMC) were collected from subjects enrolled in a cross-sectional TB immunodiagnostic study approved from the institution review board of the Albert Einstein College of Medicine (AECOM). All study subjects gave written informed consent prior to their enrollment.
Culturing of Mycobacteria and Generation of Mycobacterial Capsular Arabinomannan (AM)
Various strains of the Mycobacterium tuberculosis (Mtb) complex group comprised of laboratory strains (H37Rv, H37Ra, Erdman), clinical strains (CDC1551, Beijing) and the TB vaccine strain M. bovis Bacillus Calmette-Guerin (BCG) were pre-cultured in Middlebrook 7H9 broth supplemented with 0.05% (v/v) tyloxapol and 10% (v/v) oleic albumin dextrose catalase enrichment to reach stationary growth phase (OD600 of 0.5-1.0). Similarly, non-tuberculous mycobacterial strains (M abscesses and M. avium) were cultured. To allow for mycobacterial capsule formation, the pre-culture strains were inoculated in minimal medium without detergent at 37° C. for 3 weeks. Capsular polysaccharides were isolated by physical disruption of cells using glass beads, followed by clarification, and lyophylization. AM was separated from the other capsular components using chloroform:methanol:water extraction (1:1:0.9) and was isolated and purified as previously described. Collected fractions were assayed for carbohydrate content by the phenol-sulfuric acid assay. AM-positive fractions were tested using a standard ELISA and positive control antibody (murine mAb CS-35, BEI NR-13811). The concentrations of AM and LAM were confirmed by GC-MS calculating the ratio of arabinose to mannose.
Isolation of AM-Specific B Cells
To identify arabinomannan (AM)-positive B cells by standard B cell immunophenotyping and fluorescence activated cell sorting (FACS), AM was activated by 1-cyano-4-dimethylaminopyridinium tetrafluoroborat (CDAP) and conjugated to biotin (1:20). The AM-probe was then used with the antibody cocktail for cell staining. Lymphocytes were first identified, then live B-cells were further enriched based on CD19+CD27+. Secondary staining using streptavidin labeled with phycoerythrin (PE) was used to detect the AM-positive population. Fluorescence minus one (FMO) controls were used to set the sorting gates for double positive (AM+, IgG+) B cells. Double positive cells were sorted into a 96-well plate into RNAse-inhibiting lysis buffer.
Recombinant Generation of mAbs from Isolated Single B Cells
Reverse transcription PCR (RT-PCR) of lysed single B cells was used to synthesize complementary DNA (cDNA). Immunoglobulin genes for the heavy and light chains of the variable (V) region (Ig VH VK and VL) were amplified using random hexamer primers and sequenced. Then nested PCR was used to clone Ig genes into IgG heavy- and light-chain expression vectors and co-expressed by transfection of 293 HEK cells.
Bio Laver Interferometry
Initially, binding of the anti-AM mAbs to the biotinylated probe was tested with the OctetRed™ system (ForteBio, Pall LLC). Briefly, biotinylated AM was loaded on to streptavidin biosensor tips at 0.5 μg/ml. The loaded antigen was dipped into serially diluted mAb. Binding curves were generated and used to calculate dissociation constants. To estimate values for the kon (association rate constant), koff (dissociation rate constant), and KD (equilibrium dissociation constant), a global data fitting 2:1 binding model was used. The 2:1 heterogenous ligand model assumes analyte binding at two independent ligand sites. Each ligand site binds the analyte independently and with a different rate constant. Epitope binning is a term used to describe segmentation of a panel of monoclonal antibodies (mAbs) into bins based upon the antigen region, or epitope, bound by each antibody. This grouping is performed using cross competition assays, in which the competitive binding of antibody pairs to a specific antigen is characterized. For epitope binning experiments, a double-phase binding set-up was used; the antigen was first immobilized on a streptavidin sensor and then allowed to equilibrate in a solution containing the first mAb. The sensor was then transferred to a second solution containing the second mAb. Briefly, after AM is loaded on the biosensor tip, it is incubated with the first mAb and an association curve is observed. After the binding plateaus, the biosensor is dipped into another well containing the competitor mAb or isotype matched control mAb. The observation of a second association curve suggests that there are available binding sites on AM to the competitor mAb, but not the mAb itself.
Antibody Binding Assays
ELISA experiments were used to determine binding and estimate affinity of mAbs to isolated capsular AM, cell wall LAM, as well whole cells from different mycobacteria strains. Immunofluorescence microcopy was used to visualize the binding of mAbs to fixed Mtb with an intact capsule. Mtb was cultured in conditions to preserve the capsule and was fixed with 2% PFA before use. Poly-L-lysine slides were coated with the fixed Mtb. MAbs were incubated at 10 μg/ml for screening. Then, human mAbs were detected with tetramethylrhodamine (TRITC)-labeled goat-anti human IgG and viewed with a Zeiss observer microscope.
Synthetic AM Glycan Microarray
A novel glycan microarray comprised of 63 synthetically generated AM oligosaccharide fragments was used to determine mAb reactivity to glycan epitopes. This protocol was previously described for polyclonal sera binding and was adapted for mAb binding characterization. Briefly, microarray slides were blocked with 3% BSA in PBS at 4 C overnight, then mAbs were incubated at 5 μg/ml for 4 hrs at 37° C. After washing with PBST, the slides were first incubated with goat anti-human biotin-labeled IgG (Southern Biotech, AL) and then followed with a streptavidin probe tagged with SureLight®P3 Cy5 (Cayman Chemicals, MI) at 37° C. for 2 hrs. The GenePix 4000 Microarray scanner system (Molecular Devices, CA) was used for scanning. Images were analyzed by using GenePix Pro 7.3.0.0 to measure median pixel intensity (MPI) and neighboring background pixel intensity (BPI) of individual spots. The median fluorescence intensity (MFI), representing AM-epitope specific mAb reactivity, was calculated using the MPI minus the BPI and averaged from the triplicate spots. The median fluorescent intensity (MFI), representing AM-epitope specific mAb reactivity, was the MPI minus the BPI. The final MFI was averaged from the triplicates.
Urinary LAM Sandwich ELISA
mAbs were tested for their use as capture or detection antibodies in the urinary LAM capture sandwich ELISA. The pair of anti-LAM mAbs CS-35 (murine) and A194 (human) were used as a positive control to assess capture and detection of serially diluted LAM in urine. Capture antibodies (CS-35 and L1AM04) were used at 10 μg/mL in PBS and incubated at 4° C. overnight. Urine was spiked with known amounts of LAM and incubated with the capture antibody at 4° C. overnight. Following overnight incubation, the plate was brought to room temperature and blocked for 1 hr. After blocking, the plates were vigorously washed with the wash buffer (200 μL×10) and were incubated for 2 hr at room temperature with the biotinylated detection antibodies (A194 or T1AM09) at a final concentration of 250 ng/mL in wash buffer. Following a second wash, 100 μL of 1:200 dilution of Streptavidin-Horseradish Peroxidase (HRP) was added to the plates and incubated as per the kit protocol. After the final wash, 100 μL Ultra TMB-ELISA chromogenic substrate was added to the plates and incubated for 30 min. The reaction was stopped by addition of sulphuric acid and the optical density was read at 450 nm.
Monoclonal mAbs were generated using a targeted, flow cytometry-based strategy. Initially, subjects from a range of Mtb exposure and infection along the clinical spectrum were tested for their serum anti-AM IgG responses. Donor L1 was selected for B cell sorting and antibody generation based on having available PBMCs and anti-AM IgG titers.
Donor L1 was an asymptomatic healthcare provider, tuberculin skin test positive (>15 mm), whole blood interferon-gamma release assay (IGRA; Quantiferon TB Gold) positive.
Analysis of serial sera obtained from subject L over a period of seven years revealed persistently detectable high anti-AM IgG titers. Using PBMCs isolated from L1, AM-positive, IgG-positive memory B cells were sorted. Of the around 300 AM-positive B-cells (CD19+, CD27+), around 80 were IgG+ and sorted into individual wells. The variable heavy and light chains of the B cell receptors were recovered by nested RT-PCR and an initial panel of recombinant human mAbs were expressed in an IgG1 vector in HEK293 cells. RT-PCR sequences revealed that mAbs came from distinct germline lineages. From the about 80 AM-positive, IgG-positive B-cells, eight expressed adequate quantities of protein.
The CDR and variable chain sequences of L1AM04 are provided in Tables 2 and 3.
AQVSHFPRTFGQGTKVEIK
Consistent with antibodies to polysaccharide antigens, it was found that most of the mAbs had low mutation frequency and were less than 10% mutated from the germline sequence. For most mAbs, high concentrations were required to detect reactivity to capsular AM suggesting low binding affinities (
Both L1AM04 as well as control antibody T1AM09 (disclosed in PCT application publication WO2019/200255, which is herein incorporated by reference in its entirety) bound strongest to Mtb capsular AM, followed by LAM, and weaker binding to Mtb cell wall, membrane and culture filtrate fractions (
S
TYWIHWMRQAPGQGPEWMGWIIPKSGGT
NYAQKFQGRVAMTRDTSLNTVYMELSRLT
NYAQKFQGRVAMTRDTSLNTVYMELSRLT
SSNLNWYQQRPGKAPKLLISGISDLHSGV
To determine the AM epitopes recognized by L1AM04 and control antibody T1AM09, antibody binding to a broader panel of 63 synthetically generated oligosaccharides was tested. These synthetically generated oligosaccharides were derived from mycobacterial surface glycans which, in addition to the 30 fragments from AM and LAM, included fragments from six other glycan classes (α-glucan, trehalose mycolates, lipooligosachharides (LOSs), phenolic glycolipids (PGLs), phosphatidyl-myo-inositol mannosides (PIMs) and glycopepitdolipids (GPLs). L1AM04 reacted with AM fragments S4, S9, S25, sharing a specific mannose capped arabinan motif (
The binding affinity of L1AM04 to a biotinylated AM probe was determined using Biolayer Interferometry (BLI). Biotinylated AM was immobilized onto streptavidin sensors and then dipped into solutions of L1AM04 or control antibody T1AM09 at various concentrations. Given the bivalent nature of the IgGs, this measurement does not provide an unambiguous determination of binding kinetics without the potential for avidity but nonetheless can afford some insight into comparative affinities. Hence, the reported dissociation constants are referred to as apparent KD (KD, app).
L1AM04 bound to AM with sub-micromolar affinity and rapid association rates (Table 5). Further, cross-competition experiments by BLI indicated binding of T1AM09 and L1AM04 to different glycan epitopes within AM (
Detection of LAM in the urine of TB patients is based on the use of a capture mAb in combination with a detection mAb for LAM. These mAbs should recognize different AM/LAM epitopes. The AM OS glycan microarray and epitope binning data indicated that T1AM09, L1AM04, and CS-35 could be used as different pairs in a urinary LAM (U-LAM) sandwich ELISA (
The binding of antibody L1AM04 as well as control antibody T1AM09 to different Mtb strains (grown without detergent to preserve the capsule) was determined. Using fluorescent microscopy, it was shown that at concentrations of 10 μg/ml mAbs L1AM04 binds to both avirulent (H37Ra, BCG) and virulent laboratory (H37Rv and Erdman) as well as clinical strains (CDC1551 and Beijing) of the Mtb complex group (
To demonstrate the utility of L1AM04 for the detection of Mtb and LAM in the tissue of CDC1551 and Erdman infected mice, mAbs binding was evaluated by immunohistochemistry (IHC) staining, using Acid-Fast Bacilli (AFB) staining (Ziehl-Neelsen) as a positive control. Both L1AM04 and control antibody T1AM09 detected extracellular and intracellular bacilli and AM/LAM throughout infected lungs with minimal off-target effects (
Monoclonal antibody P1AM25 was generated using the targeted, flow cytometry-based strategy described in Example 1. Donor P1 was selected for B cell sorting and antibody generation. Donor P1 was an asymptomatic, Mantoux tuberculin skin test (TST)+ and interferon-gamma release assay (IGRA; QuantiFERON-TB Gold In-Tube) positive foreign-born adult with a reported history of childhood TB.
The CDR and variable chain sequences of P1AM25 are provided in Tables 6 and 7.
The binding of antibody P1AM25 to capsular AMV was assessed using an ELISA. For this, AM isolated from H37Rv was coated on a 96-well Maxisorp plate at 10 μg/mL. Anti-Mtb AM mAbs P1AM25, T1AM09, and L1AM04 were applied as primary antibodies and the binding was detected using an HRP-conjugated anti-human IgG-Fc.
Human monoclonal antibody P1AM25 showed an exceptionally high affinity compared to high affinity anti-AM monoclonal antibodies T1AM109 and L1AM04 (
To determine M. tuberculosis phagocytosis by U937R3a cells or THP1 cells (both human monocyte cell lines), respectively, in presence of anti-AM mAbs, phorbol-12-myristate-13-acetate (PMA)-differentiated U937R3a cells or THP1 cells, respectively, were seeded at 5×104 (U937R3a cells) or 1×105 (THP1 cells) per well in a 96-well plate. The cells were infected with H37Ra-FITC at MOI of 20 in the presence of different anti-AM mAbs at for 3 hours.
Enhanced M. tuberculosis phagocytosis by U937R3a cells (
The reactivity of P1AM25 to mycobacterial envelope glycan epitopes was compared to murine mAb CS35 and human mAbs T1AM09 and L1AM04 using a panel of 63 synthetically generated oligosaccharides (
The binding affinity of antibody P1AM25 was determined with BLI (biotinylated AM: 0.5 μg/mL; antibody 2.3 nM-37.5 nM). The KD was determined to be 3.38 10−9 M.
Epitope binning experiments for P1AM25 were performed using BLI. Performed were two-phase binding experiment detecting P1AM25 and A194 (
To determine the effect of antibody P1AM25 on intracellular Mtb growth in PMA-differentiated THP-1 cells, the cells seeded at 0.5×105 per well in a 96-well plate. The cells were infected with H37Rv at MOI of 1 in the presence of different AM mAbs at 5 μg/mL for 2 hours (D1). Wells were washed and cell lysates were plated on 7H10 agar plate after infection to determine the uptake of bacteria on D1. Wells for D3 were washed, refilled with fresh media containing mAbs, and incubated for 48 hours. Supernatant and cell lysates were plated on 7H10 agar plate on D3. An intracellular growth reduction of Mtb in THP-1 cell in the presence of P1AM25 was observed (
This invention was made with government support under grant number 1 R01 AI146329 awarded by National Institutes of Health/National Institute of Allergy and Infectious Diseases. The government has certain rights in the invention.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2021/063461 | 12/15/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63199235 | Dec 2020 | US |
