Brain-specific angiogenesis inhibitor 1 (BAI1) antibody and its uses

Abstract

This disclosure provides antibodies that bind to human adhesion G protein-coupled receptor B1 (BAI1) protein, compositions comprising said antibodies, and their use in detection, diagnostic, and therapeutic methods. Sequences of complementarity-determining regions (CDRs) in the variable heavy chain (VH) and variable light chain (VL) sequences, as well as the amino acid sequences of VH and VL, are also provided.

Description

[0001] References to sequence lists

[0002] This application includes a sequence list submitted electronically as a text file, named 18909900502SEQ, created on November 2, 2020, and measuring 25 kilobytes in size. This sequence list is incorporated herein by reference. Technical Field

[0003] This disclosure relates to antibodies and fragments thereof that bind to human brain-specific angiogenesis inhibitor 1 (BAI1) (also known as adhesion G protein-coupled receptor B1 (ADGRB1)), compositions comprising said antibodies and fragments thereof, and their use in detection methods, cell separation methods, exhaustion methods, diagnostic methods, and treatment methods. Background Technology

[0004] BAI1 is expressed in mononuclear cell lineage cells, astrocytes, neurons, and Myo / Nog cells, which express the skeletal muscle-specific transcription factor MyoD and the bone morphogenetic inhibitor noggin. + Cells are involved in innate immunity, wound healing, embryonic development, and neuroprotection. BAI1 + Cellular wound healing properties are partly reflected in the role of this molecule in phagocytosis and apoptosis of cells and Gram-negative bacteria through its binding to phosphatidylserine. BAI1 + Another function of cell subsets during wound healing is the differentiation into myofibroblasts. While myofibroblast contraction promotes wound closure, they can also disrupt tissue morphology and thus function. For example, secondary cataracts, or posterior capsular opacity (PCO), are lens diseases that impair vision and develop in some adults and most children after cataract surgery. BAI1 in the lens... + Cells develop into myofibroblasts and create wrinkles in the lens capsule (the thick basement membrane that surrounds the lens). Deformity of the lens capsule can affect vision.

[0005] Besides its role in phagocytosis, BAI1 also metabolizes to produce angiogenesis inhibitors, the process by which blood vessels develop from pre-existing vessels. In the retina, angiogenesis is a vision-threatening component in diabetic retinopathy and wet macular degeneration. Angiogenesis is also crucial for tumor growth; unless tumors acquire additional growth, they cannot grow beyond a few millimeters. + Cells are present in the retina and tumors. In some cancers, BAI1 is downregulated as the disease progresses, thus promoting angiogenesis. However, angiogenesis is also important for the distribution of chemotherapy drugs, such as those that attach to viruses. Summary of the Invention

[0006] This disclosure provides an antibody or antigen-binding fragment thereof that binds to human BAI1 protein, wherein the antibody or antigen-binding fragment thereof comprises: variable weight (V H The first complementarity-determining region (CDR) in the chain (V H -CDR1), which comprises or consists of the amino acid sequence according to SEQ ID NO:7; the V H The second CDR (V) in the chain H -CDR2), which comprises or consists of the amino acid sequence according to SEQ ID NO:8; the V H The third CDR (V) in the chain H -CDR3), which comprises or consists of the amino acid sequence according to SEQ ID NO:9; variable light (V L The first CDR (V) in the chain L -CDR1), which comprises or consists of the amino acid sequence according to SEQ ID NO:10; the V L The second CDR (V) in the chain L -CDR2), comprising or consisting of the amino acid sequence according to SEQ ID NO:11; and the V L The third CDR (V) in the chain L -CDR3), which contains or consists of the amino acid sequence according to SEQ ID NO:12.

[0007] This disclosure also provides isolated nucleic acid molecules of heavy chains encoding the antibody or an antigen-binding fragment thereof, wherein the nucleic acid molecule comprises or is composed of a nucleotide sequence according to SEQ ID NO:2 or SEQ ID NO:3.

[0008] This disclosure also provides isolated nucleic acid molecules encoding a light chain of the antibody or an antigen-binding fragment thereof, wherein the nucleic acid molecule comprises or is composed of a nucleotide sequence according to SEQ ID NO:5 or SEQ ID NO:6.

[0009] This disclosure also provides a method for detecting cells expressing BAI1, the method comprising contacting the cells with an antibody or an antigen-binding fragment thereof described herein, and detecting the antibody or the antigen-binding fragment thereof. The detection can occur in fixed tissues, cell cultures, and live animals, and is used for cell tracing and bioimaging.

[0010] This disclosure also provides methods for purifying BAI1, the methods comprising contacting the molecule with an antibody or an antigen-binding fragment thereof described herein. These methods include, for example, immunoprecipitation and column purification.

[0011] This disclosure also provides methods for isolating live cells expressing BAI1, the methods comprising contacting the cells with the antibody or an antigen-binding fragment thereof, and separating cells bound to the antibody or antigen-binding fragment from unbound cells as described herein. These methods include, for example, fluorescence-activated cell sorting (FACS) and magnetic cell sorting.

[0012] This disclosure also provides methods for analyzing BAI1 function, methods comprising contacting molecules and live cells, both in vitro and in vivo, with antibodies or antigen-binding fragments thereof described herein. These methods include, for example, blocking receptors and fragments thereof for enzyme-linked immunosorbent assay (ELISA), immunoprecipitation, Western blotting, and live cell assays.

[0013] This disclosure also provides methods for killing BAI1-expressing cells in vitro and in animals to determine cell function, and methods for killing said cells in human patients in need of this, the methods comprising administering the antibody described herein or an antigen-binding fragment thereof.

[0014] This disclosure also provides methods for treating cancers expressing BAI1 in cell cultures and in tumor-bearing animals and humans, said methods comprising administering the antibody described herein or an antigen-binding fragment thereof.

[0015] This disclosure also provides a method for treating posterior capsule opacification (PCO), the method comprising administering the antibody or antigen-binding fragment thereof described herein to tissue cultures, animals, and human patients in need of such treatment.

[0016] This disclosure also provides a method for treating fibrosis, the method comprising administering the antibody described herein or an antigen-binding fragment thereof to cultured cells, animals, or human patients in need of such treatment.

[0017] The present invention also provides a method for promoting wound healing, the method comprising administering to a patient in need an antibody or antigen-binding fragment thereof described herein, or BAI1. + Any type of wound in the cell. Attached Figure Description

[0018] Figure 1 An antigen identification workflow using the membrane proteome array (MPA) platform is shown.

[0019] Figure 2A The optimized immunoassay for G8 batch 3 / 21 / 13 in HEK-293T cells is shown. Each point represents the average of four replicates. Recommended working concentrations for each antibody, screened based on signal-to-background ratio (S / B) calculations and raw signal values, are highlighted in red.

[0020] Figure 2BThe optimized immunoassay for G8 batch PS30170160 in HEK-293T cells is shown. Each point represents the average of four replicates. Recommended working concentrations for each antibody, screened based on signal-to-background ratio (S / B) calculations and raw signal values, are highlighted in red.

[0021] Figure 3A The identification of membrane protein binding targets in batch G8, 3 / 21 / 13, is shown. Non-specific fluorescence was determined to be any value more than 3 standard deviations above the noise (dashed line). Targets showing increased antibody binding are shown above the dashed line and indicated in red.

[0022] Figure 3B The identification of membrane protein binding targets for G8 batch PS30170160 is shown. Non-specific fluorescence was determined to be any value above the noise (dashed line) by 3 standard deviations. Targets showing increased antibody binding are shown above the dashed line and indicated in red.

[0023] Figure 4A The validation of the combination of batch G8 3 / 21 / 13 is shown. Each point represents the average of four replicates.

[0024] Figure 4B The validation of the combination of G8 batch PS30170160 is shown. Each point represents the average of four replicates.

[0025] Figure 5 The results of RACE identification of the heavy and light chains of mouse G8 IgM are shown.

[0026] Figure 6 The results of ELISA assays for G8 IgM (box) and anti-BAI1 IgG (circle; also referred to herein as “G8 IgG”) are shown.

[0027] It should be understood that the foregoing overview and the following details are exemplary and illustrative only and not limiting of the implementation schemes claimed herein. Detailed Implementation

[0028] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be restrictive. Various terms relating to aspects of this disclosure are used throughout the specification and claims. Unless otherwise stated, such terms will be given their ordinary meaning in the art. Other specifically defined terms should be interpreted in a manner consistent with the definitions provided herein.

[0029] Unless otherwise expressly stated, it is by no means intended to interpret any method or aspect set forth herein as requiring its steps to be performed in any particular order. Where a method claim does not specifically specify in the claims or description that the steps are limited to a particular order, it is by no means intended that the order can be inferred in any respect. This applies to any possible non-explicit basis of interpretation, including logical questions concerning the arrangement of steps or the flow of operations, simple meanings derived from grammatical composition or punctuation, or the number or type of aspects described in the description.

[0030] As used herein, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” include multiple referents.

[0031] As used herein, the term “about” means that the listed values ​​are approximate and that small variations will not significantly affect the practice of the disclosed embodiments. When using numerical values, unless the context otherwise indicates, “about” means that the values ​​may vary by ±10% and still remain within the range of the disclosed embodiments.

[0032] As used herein, the term "antibody" refers to an immunoglobulin molecule that specifically binds to or is immunoreactive with a particular antigen, and includes its polyclonal, monoclonal, genetically engineered, and other modified forms, including but not limited to chimeric antibodies, humanized antibodies, and heteroconjugated antibodies (e.g., bispecific antibodies, double-stranded antibodies, triple-stranded antibodies, and quadruple-stranded antibodies).

[0033] As used herein, the phrase "its antigen-binding fragment" refers to an antibody fragment capable of binding to an antigen. Antigen-binding fragments include, but are not limited to, Fab, Fab', F(ab')2, Fv, scFv, scFv-Fc, double-chain antibodies, bispecific double antibodies, trispecific triple-chain antibodies, microantibodies, monospecific Fab2, bispecific Fab2, trispecific Fab3, nanobodies, IgNAR, V-NAR, hcIgG, and VhH fragments.

[0034] As used herein, the phrase "chimeric antibody" refers to an antibody having a variable sequence derived from a non-human immunoglobulin (such as a rat or mouse antibody) and a human immunoglobulin constant region typically selected from a human immunoglobulin template.

[0035] As used herein, the term "Fv" fragment refers to the smallest antibody fragment containing complete target recognition and binding sites. This region consists of a nonvalently associated dimer (V) of a heavy chain variable domain and a light chain variable domain. H -V L It consists of a dimer. It is in this configuration that the three CDRs of each variable structural domain interact to define V. H -V LTarget binding sites on the surface of the dimer.

[0036] As used herein, the phrase “human antibody” refers to an antibody having the amino acid sequence of a human immunoglobulin and includes antibodies isolated from a human immunoglobulin library or from animals that are transgenic to one or more human immunoglobulins and do not express endogenous immunoglobulins.

[0037] As used herein, the phrase "humanized antibody" refers to a chimeric antibody or antigen-binding fragment thereof containing a minimal sequence derived from a non-human immunoglobulin. Generally, a humanized antibody will contain at least one, and typically substantially all, of two variable domains, wherein all or substantially all of the CDR regions correspond to those CDR regions of the non-human immunoglobulin, and all or substantially all of the frame (FR) regions are those FR regions of the human immunoglobulin sequence. Humanized antibodies may also contain immunoglobulin constant regions (Fc), typically at least a portion of the constant regions of the common sequence of human immunoglobulins.

[0038] As used herein, the phrase "in need" means a "subject" or "patient" identified as needing a particular method, prevention, or treatment. In some implementations, identification may be performed by any diagnostic means. In any of the methods, preventions, and treatments described herein, a "subject" or "patient" may be in need.

[0039] As used in this article, a "nucleic acid molecule" is a polymer of nucleotides of any length, which may contain DNA and / or RNA, and may be single-stranded, double-stranded, or multi-stranded. One strand of a nucleic acid also refers to its complementary strand.

[0040] As used in this article, the phrase "primate-derived antibody" refers to an antibody that contains both monkey variable regions and human constant regions.

[0041] As used in this article, the phrase “regulatory sequence” is intended to include promoters, enhancers, and other expression control elements that control the transcription or translation of antibody chain genes, such as polyadenylation signals.

[0042] As used herein, the terms "single-chain Fv" or "scFv" refer to single-chain Fv antibodies, in which the variable domains (V1 and V2) derived from the heavy and light chains of conventional antibodies are used. H and V L The structural domains have been linked together to form a chain. Typically, Fv polypeptides also contain intermediates between V and V. H and V L A peptide linker between structural domains enables scFv to form the structure required for target binding.

[0043] As used herein, the terms “subject” and “patient” are used interchangeably. A subject includes any animal, including mammals. Mammals include, but are not limited to, farm animals (e.g., horses, cattle, pigs), companion animals (e.g., dogs, cats), laboratory animals (e.g., mice, rats, rabbits), and non-human primates (e.g., monkeys). In some embodiments, the subject or patient is a human.

[0044] As used in this article, the term "V" H "" refers to the variable region of the immunoglobulin heavy chain of the antibody (including, for example, the heavy chain of Fv, scFv or Fab fragments).

[0045] As used in this article, the term "V" L "" refers to the variable region of the immunoglobulin light chain of the antibody (including light chains such as Fv, scFv, dsFv or Fab fragments).

[0046] This disclosure provides antibodies or antigen-binding fragments thereof that bind to the BAI1 protein (also known as the G8 antigen). In some embodiments, the BAI1 protein comprises or consists of the following amino acid sequence: MRGQAAAPGPVWILAPLLLLL

[0047]

[0048] In some embodiments, the antibody or antigen-binding fragment described herein binds to an epitope within the human BAI1 protein, said epitope comprising or consisting of the following amino acids: Y83, F135, W415, W418, L420, T424, R432, R434, I458, W473, W476, R545, Y639, and L776. In some embodiments, the epitope within the human BAI1 protein bound by the antibody or antigen-binding fragment described herein comprises or consists of the following amino acids: at least 4 to 14, at least 4 to 13, at least 4 to 12, at least 4 to 11, at least 4 to 10, at least 4 to 9, at least 4 to 8, at least 4 to 7, or at least 4 to 6 of these amino acids. In some embodiments, the epitope in the human BAI1 protein bound by the antibody or antigen-binding fragment described herein comprises or consists of at least 6 to 14, at least 6 to 13, at least 6 to 12, at least 6 to 11, at least 6 to 10, at least 6 to 9, or at least 6 to 8 of these amino acids. In some embodiments, the epitope in the human BAI1 protein bound by the antibody or antigen-binding fragment described herein comprises or consists of at least 7 to 14, at least 7 to 13, at least 7 to 12, at least 7 to 11, at least 7 to 10, or at least 7 to 9 of these amino acids. In some embodiments, the antibody or antigen-binding fragment described herein binds to an epitope in the human BAI1 protein, said epitope comprising or consisting of the following amino acids: F135, W415, W418, L420, T424, R432, R434, and I458. In some embodiments, the antibody described herein or its antigen-binding fragment binds to an epitope within the human BAI1 protein, said epitope comprising or consisting of the following amino acids: W415, W418, L420, T424, R432, R434, and I458. In some embodiments, the antibody described herein or its antigen-binding fragment binds to an epitope within the human BAI1 protein, said epitope comprising or consisting of the following amino acids: T424, R432, R434, and I458.

[0049] This disclosure also provides antibodies or antigen-binding fragments thereof that bind to the human BAI1 protein. In some embodiments, the antibody or antigen-binding fragment thereof comprises three V... H CDR and three V L CDR.

[0050] In some embodiments, the antibody or its antigen-binding fragment contains V H The first CDR (V) in the chain H-CDR1), which contains the amino acid sequence GYSITSDY (SEQ ID NO:7) or is composed of said amino acid sequence. In some embodiments, the V H -CDR1 can contain one, two, or three conserved amino acid substitutions or be composed of one, two, or three conserved amino acid substitutions.

[0051] In some embodiments, the antibody or its antigen-binding fragment contains V H The second CDR (V) in the chain H -CDR2), which contains the amino acid sequence SYSGS (SEQ ID NO:8) or is composed of said amino acid sequence. In some embodiments, the V H -CDR2 can contain one or two conserved amino acid substitutions or be composed of one or two conserved amino acid substitutions.

[0052] In some embodiments, the antibody or its antigen-binding fragment contains V H The third CDR (V) in the chain H -CDR3), which contains the amino acid sequence AQGYAMDY (SEQ ID NO:9) or is composed of said amino acid sequence. In some embodiments, the V H -CDR3 can contain one, two, or three conserved amino acid substitutions or be composed of one, two, or three conserved amino acid substitutions.

[0053] In some embodiments, the antibody or its antigen-binding fragment contains V L The first CDR (V) in the chain L -CDR1), which comprises the amino acid sequence RASQSISDYLH (SEQ ID NO:10) or is composed of said amino acid sequence. In some embodiments, the V L -CDR1 can contain one, two, three, or four conserved amino acid substitutions or be composed of one, two, three, or four conserved amino acid substitutions.

[0054] In some embodiments, the antibody or its antigen-binding fragment contains V L The second CDR (V) in the chain L -CDR2), which contains the amino acid sequence YASQSIS (SEQ ID NO:11) or is composed of said amino acid sequence. In some embodiments, the V L -CDR2 can contain one or two conserved amino acid substitutions or be composed of one or two conserved amino acid substitutions.

[0055] In some embodiments, the antibody or its antigen-binding fragment contains V L The third CDR (V) in the chainL -CDR3), which contains the amino acid sequence QNGHSFPFT (SEQ ID NO:12) or is composed of said amino acid sequence. In some embodiments, the V L -CDR3 can contain one, two, or three conserved amino acid substitutions or be composed of one, two, or three conserved amino acid substitutions.

[0056] In some embodiments, the antibody or its antigen-binding fragment comprises: V H The first CDR (V) in the chain H -CDR1), which contains the amino acid sequence GYSITSDY (SEQ ID NO:7) or is composed of said amino acid sequence; V H The second CDR (V) in the chain H -CDR2), which contains the amino acid sequence SYSGS (SEQ ID NO:8) or is composed of said amino acid sequence; V H The third CDR (V) in the chain H -CDR3), which contains the amino acid sequence AQGYAMDY (SEQ ID NO:9) or is composed of said amino acid sequence; V L The first CDR (V) in the chain L -CDR1), which contains the amino acid sequence RASQSISDYLH (SEQ ID NO:10) or is composed of said amino acid sequence; V L The second CDR (V) in the chain L -CDR2), which contains the amino acid sequence YASQSIS (SEQ ID NO:11) or is composed of said amino acid sequence; and V L The third CDR (V) in the chain L -CDR3), comprising or consisting of the amino acid sequence QNGHSFPFT (SEQ ID NO:12). In some embodiments, CDR may have the conserved amino acid substitutions described herein.

[0057] In some embodiments, the antibody or its antigen-binding fragment contains V H A chain that contains or is composed of the following amino acid sequence: SDVQLQESGPG

[0058] LVKPSQSLSLTCTVTGYSITSDYAWNWIRQFPGNKLEWMGYISYSGSTSYNPSLKSRISITRDTSKNQFFLQLNSVTTEDTATYYCANAQGYAMDYWGQGTSVTVSS (SEQ ID NO:1). In some embodiments, the antibody or its antigen-binding fragment comprises a V consisting of an amino acid sequence according to SEQ ID NO:1. H chain.

[0059] In some embodiments, the antibody or its antigen-binding fragment contains V H The chain comprises or consists of an amino acid sequence having at least about 85%, at least about 90%, at least about 92%, at least about 94%, at least about 96%, or at least about 98% sequence identity with SEQ ID NO:1. In some embodiments, the antibody or its antigen-binding fragment comprises V H The chain comprises or consists of an amino acid sequence having at least about 85% sequence identity with SEQ ID NO:1. In some embodiments, the antibody or its antigen-binding fragment comprises V H A chain comprising or consisting of an amino acid sequence having at least about 90% sequence identity with SEQ ID NO:1. In some embodiments, the antibody or its antigen-binding fragment comprises V H The chain comprises or consists of an amino acid sequence having at least about 92% sequence identity with SEQ ID NO:1. In some embodiments, the antibody or its antigen-binding fragment comprises V H The chain comprises or consists of an amino acid sequence having at least about 94% sequence identity with SEQ ID NO:1. In some embodiments, the antibody or its antigen-binding fragment comprises V H The chain comprises or consists of an amino acid sequence having at least about 96% sequence identity with SEQ ID NO:1. In some embodiments, the antibody or its antigen-binding fragment comprises V H A chain comprising or consisting of an amino acid sequence having at least about 98% sequence identity with SEQ ID NO:1. In some embodiments, V H The chain contains any V described in this article. H CDR. In some implementations, V H The CDR contains the amino acid sequences according to SEQ ID NO:7, SEQ ID NO:8, and SEQ ID NO:9. In some embodiments, V HThe chain contains one, two, three, four, five, six, seven, or eight conserved amino acid substitutions, or is composed of one, two, three, four, five, six, seven, or eight conserved amino acid substitutions. In some embodiments, V H The chain contains one, two, three, four, five, six, seven, or eight conserved amino acid substitutions outside the CDR, or is composed of one, two, three, four, five, six, seven, or eight conserved amino acid substitutions outside the CDR.

[0060] In some embodiments, the antibody or its antigen-binding fragment contains V L A chain that contains or is composed of the following amino acid sequence: DIVMTQSPA

[0061] TLSVTPGDRVSLSCRASQSISDYLHWYQQKSHESPRLLIKYASQSISGIPSRFSGSGS

[0062] GSDFTLSINSVEPEDVGVYYCQNGHSFPFTFGSGTKLEIK (SEQ ID NO:4). In some embodiments, the antibody or its antigen-binding fragment comprises a V consisting of an amino acid sequence according to SEQ ID NO:4. L chain.

[0063] In some embodiments, the antibody or its antigen-binding fragment contains V L The chain comprises or consists of an amino acid sequence having at least about 85%, at least about 90%, at least about 92%, at least about 94%, at least about 96%, or at least about 98% sequence identity with SEQ ID NO:4. In some embodiments, the antibody or its antigen-binding fragment comprises V L The chain comprises or consists of an amino acid sequence having at least about 85% sequence identity with SEQ ID NO:4. In some embodiments, the antibody or its antigen-binding fragment comprises V L The chain comprises or consists of an amino acid sequence having at least about 90% sequence identity with SEQ ID NO:4. In some embodiments, the antibody or its antigen-binding fragment comprises V L The chain comprises or consists of an amino acid sequence having at least about 92% sequence identity with SEQ ID NO:4. In some embodiments, the antibody or its antigen-binding fragment comprises V LThe chain comprises or consists of an amino acid sequence having at least about 94% sequence identity with SEQ ID NO:4. In some embodiments, the antibody or its antigen-binding fragment comprises V L The chain comprises or consists of an amino acid sequence having at least about 96% sequence identity with SEQ ID NO:4. In some embodiments, the antibody or its antigen-binding fragment comprises V L A chain comprising or consisting of an amino acid sequence having at least about 98% sequence identity with SEQ ID NO:4. In some embodiments, V L The chain contains any V described in this article. L CDR. In some implementations, V L The CDR contains the amino acid sequences according to SEQ ID NO:10, SEQ ID NO:11, and SEQ ID NO:12. In some embodiments, V L The chain contains one, two, three, four, five, six, seven, or eight conserved amino acid substitutions. In some embodiments, V L The chain contains one, two, three, four, five, six, seven, or eight conserved amino acid substitutions outside the CDR.

[0064] In some embodiments, the antibody or its antigen-binding fragment comprises V containing the amino acid sequence according to SEQ ID NO:1. H The chain and V containing the amino acid sequence according to SEQ ID NO:4 L Chain. In some embodiments, the antibody or its antigen-binding fragment comprises a V consisting of an amino acid sequence according to SEQ ID NO:1. H The chain and the V composed of the amino acid sequence according to SEQ ID NO:4 L chain.

[0065] In some embodiments, the antibody or its antigen-binding fragment contains V H Chain and V L The chain comprises, respectively, an amino acid sequence having at least about 85%, at least about 90%, at least about 92%, at least about 94%, at least about 96%, or at least about 98% sequence identity with SEQ ID NO:1 and SEQ ID NO:4, or is composed of said amino acid sequences. In some embodiments, the antibody or its antigen-binding fragment comprises V H Chain and V LThe chain comprises, or is composed of, an amino acid sequence having at least about 85% sequence identity with SEQ ID NO:1 and SEQ ID NO:4. In some embodiments, the antibody or its antigen-binding fragment comprises V H Chain and V L The chain comprises, or is composed of, an amino acid sequence having at least about 90% sequence identity with SEQ ID NO:1 and SEQ ID NO:4. In some embodiments, the antibody or its antigen-binding fragment comprises V H Chain and V L The chain comprises, or is composed of, an amino acid sequence having at least about 92% sequence identity with SEQ ID NO:1 and SEQ ID NO:4. In some embodiments, the antibody or its antigen-binding fragment comprises V H Chain and V L The chain comprises, or is composed of, an amino acid sequence having at least about 94% sequence identity with SEQ ID NO:1 and SEQ ID NO:4, respectively. In some embodiments, the antibody or its antigen-binding fragment comprises V H Chain and V L The chain comprises, or is composed of, an amino acid sequence having at least about 96% sequence identity with SEQ ID NO:1 and SEQ ID NO:4. In some embodiments, the antibody or its antigen-binding fragment comprises V H Chain and V L The chains, respectively comprising or consisting of amino acid sequences having at least about 98% sequence identity with SEQ ID NO:1 and SEQ ID NO:4. In some embodiments, V H Chain and V L The chain contains any V described in this article. H CDR and V L CDR. In some implementations, V H The CDR contains the amino acid sequences according to SEQ ID NO:7, SEQ ID NO:8, and SEQ ID NO:9. In some embodiments, V L The CDR comprises or consists of the amino acid sequences according to SEQ ID NO:10, SEQ ID NO:11, and SEQ ID NO:12. In some embodiments, V H Chain and V LEach chain may contain one, two, three, four, five, six, seven, or eight conserved amino acid substitutions, or be composed of one, two, three, four, five, six, seven, or eight conserved amino acid substitutions. In some embodiments, V H Chain and V L Each chain may contain one, two, three, four, five, six, seven, or eight conserved amino acid substitutions outside the CDR, or may be composed of one, two, three, four, five, six, seven, or eight conserved amino acid substitutions outside the CDR.

[0066] The antibody or its antigen-binding fragment can be any isotype. In some embodiments, the antibody is an IgM or IgG antibody. In some embodiments, the antibody is an IgM antibody. In some embodiments, the antibody is an IgG antibody. In some embodiments, the antibody is an IgG1 antibody. In some embodiments, the IgG1 antibody is an allotype antibody of IgG1 Glm1, Glm2, Glm3, Glm17, nGlmI, nGlm2, or nGlm17. In some embodiments, the antibody is an IgG1 Glm17 allotype antibody.

[0067] In some embodiments, the variant IgG1 heavy chain pairs with the κ light chain of an allotype Km1, Km2, or Km3. In some embodiments, the variant IgG1 heavy chain pairs with the λ light chain.

[0068] In some embodiments, the antibody or its antigen-binding fragment is humanized and is IgG. In some embodiments, the antibody or its antigen-binding fragment is humanized and is IgG1.

[0069] In some embodiments, the antibody or its antigen-binding fragment is a chimeric antibody or its antigen-binding fragment. Methods for generating chimeric antibodies are known in the art (see Morrison, Science, 1985, 229, 1202-1207; Oi et al., BioTechniques, 1986, 4, 214-221; Gillies et al., J. Immunol. Methods, 1985, 125, 191-202; and U.S. Patent Nos. 5,807,715, 4,816,567, and 4,816,397).

[0070] In some embodiments, the chimeric antibody or its antigen-binding fragment is a primate-derived chimeric antibody or its antigen-binding fragment. Methods for generating primate-derived antibodies are known in the art (see U.S. Patents 5,658,570, 5,681,722, and 5,693,780).

[0071] In some embodiments, the chimeric antibody or its antigen-binding fragment is a humanized antibody or its antigen-binding fragment. Methods for generating humanized antibodies are known in the art (see Riechmann et al., Nature, 1988, 332, 323-327; Padlan, Mol. Immunol., 1991, 28, 489-498; Studnicka et al., Prot. Eng., 1994, 7, 805-814; Roguska et al., Proc. Natl. Acad. Sci., 1994, 91, 969-973; European Patent Nos. EP239400, EP592106 and EP519596; PCT Publication WO 91 / 09967; and US Patent Nos. 5,225,539, 5,530,101, 5,585,089, 5,693,761, 5,693,762, 6,180,370 and 5,565,332).

[0072] In some embodiments, the humanized antibody or its antigen-binding fragment comprises a heavy chain containing or consisting of the following amino acid sequence: VQLQESGPGLVKPSQSLSLTCTVTGYSITSDYAWNWIRQFPGNKLEWMGYISYSGST

[0073] SYNPSLKSRISITRDTSKNQFFLQLNSVTTEDTATYYCANAQGYAMDYWGQGTSVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMIS RTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLP PSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG(SEQ ID NO:13). In some embodiments, the humanized antibody or its antigen-binding fragment comprises a heavy chain consisting of an amino acid sequence according to SEQ ID NO:13.

[0074] In some embodiments, the humanized antibody or its antigen-binding fragment comprises a heavy chain containing or consisting of an amino acid sequence having at least about 85%, at least about 90%, at least about 92%, at least about 94%, at least about 96%, or at least about 98% sequence identity with SEQ ID NO:13. In some embodiments, the humanized antibody or its antigen-binding fragment comprises a heavy chain containing or consisting of an amino acid sequence having at least about 85% sequence identity with SEQ ID NO:13. In some embodiments, the humanized antibody or its antigen-binding fragment comprises a heavy chain containing or consisting of an amino acid sequence having at least about 90% sequence identity with SEQ ID NO:13. In some embodiments, the humanized antibody or its antigen-binding fragment comprises a heavy chain containing or consisting of an amino acid sequence having at least about 92% sequence identity with SEQ ID NO:13. In some embodiments, the humanized antibody or its antigen-binding fragment comprises a heavy chain containing or consisting of an amino acid sequence having at least about 94% sequence identity with SEQ ID NO:13. In some embodiments, the humanized antibody or its antigen-binding fragment comprises a heavy chain containing or consisting of an amino acid sequence having at least about 96% sequence identity with SEQ ID NO:13. In some embodiments, the humanized antibody or its antigen-binding fragment comprises a heavy chain containing or consisting of an amino acid sequence having at least about 98% sequence identity with SEQ ID NO:13. In some embodiments, the heavy chain comprises any of the V... H CDR. In some embodiments, the heavy chain CDR comprises the amino acid sequence according to SEQ ID NO:7, SEQ ID NO:8, and SEQ ID NO:9. In some embodiments, the heavy chain comprises one, two, three, four, five, six, seven, eight, nine, or ten conserved amino acid substitutions. In some embodiments, the heavy chain comprises one, two, three, four, five, six, seven, eight, nine, or ten conserved amino acid substitutions outside the CDR.

[0075] In some embodiments, the humanized antibody or its antigen-binding fragment comprises a light chain containing or consisting of the following amino acid sequence: DIVMTQSPATLSVTPGDRVSLSCRASQSISDYLHWYQQKSHESPRLLIKYASQSISGIP

[0076] SRFSGSGSGSDFTLSINSVEPEDVGVYYCQNGHSFPFTFGSGTKLEIKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC (SEQ ID NO:14). In some embodiments, the humanized antibody or its antigen-binding fragment comprises a light chain consisting of an amino acid sequence according to SEQ ID NO:14.

[0077] In some embodiments, the humanized antibody or its antigen-binding fragment comprises a light chain containing or consisting of an amino acid sequence having at least about 85%, at least about 90%, at least about 92%, at least about 94%, at least about 96%, or at least about 98% sequence identity with SEQ ID NO:14. In some embodiments, the humanized antibody or its antigen-binding fragment comprises a light chain containing or consisting of an amino acid sequence having at least about 85% sequence identity with SEQ ID NO:14. In some embodiments, the humanized antibody or its antigen-binding fragment comprises a light chain containing or consisting of an amino acid sequence having at least about 90% sequence identity with SEQ ID NO:14. In some embodiments, the humanized antibody or its antigen-binding fragment comprises a light chain containing or consisting of an amino acid sequence having at least about 92% sequence identity with SEQ ID NO:14. In some embodiments, the humanized antibody or its antigen-binding fragment comprises a light chain containing or consisting of an amino acid sequence having at least about 94% sequence identity with SEQ ID NO:14. In some embodiments, the humanized antibody or its antigen-binding fragment comprises a light chain containing or consisting of an amino acid sequence having at least about 96% sequence identity with SEQ ID NO:14. In some embodiments, the humanized antibody or its antigen-binding fragment comprises a light chain containing or consisting of an amino acid sequence having at least about 98% sequence identity with SEQ ID NO:14. In some embodiments, the light chain comprises any of the V... LCDR. In some embodiments, the light chain CDR comprises the amino acid sequence according to SEQ ID NO:10, SEQ ID NO:11, and SEQ ID NO:12. In some embodiments, the light chain comprises or is composed of one, two, three, four, five, six, seven, eight, nine, or ten conserved amino acid substitutions. In some embodiments, the light chain comprises or is composed of one, two, three, four, five, six, seven, eight, nine, or ten conserved amino acid substitutions outside the CDR.

[0078] In some embodiments, the humanized antibody or its antigen-binding fragment comprises a heavy chain and a light chain, which respectively comprise or consist of an amino acid sequence having at least about 85%, at least about 90%, at least about 92%, at least about 94%, at least about 96%, or at least about 98% sequence identity with SEQ ID NO:13 and SEQ ID NO:14. In some embodiments, the humanized antibody or its antigen-binding fragment comprises a heavy chain and a light chain, which respectively comprise or consist of an amino acid sequence having at least about 85% sequence identity with SEQ ID NO:13 and SEQ ID NO:14. In some embodiments, the humanized antibody or its antigen-binding fragment comprises a heavy chain and a light chain, which respectively comprise or consist of an amino acid sequence having at least about 90% sequence identity with SEQ ID NO:13 and SEQ ID NO:14. In some embodiments, the humanized antibody or its antigen-binding fragment comprises a heavy chain and a light chain, each comprising or consisting of an amino acid sequence having at least about 92% sequence identity with SEQ ID NO:13 and SEQ ID NO:14. In some embodiments, the humanized antibody or its antigen-binding fragment comprises a heavy chain and a light chain, each comprising or consisting of an amino acid sequence having at least about 94% sequence identity with SEQ ID NO:13 and SEQ ID NO:14. In some embodiments, the humanized antibody or its antigen-binding fragment comprises a heavy chain and a light chain, each comprising or consisting of an amino acid sequence having at least about 96% sequence identity with SEQ ID NO:13 and SEQ ID NO:14. In some embodiments, the humanized antibody or its antigen-binding fragment comprises a heavy chain and a light chain, each comprising or consisting of an amino acid sequence having at least about 98% sequence identity with SEQ ID NO:13 and SEQ ID NO:14. In some embodiments, the heavy chain and light chain comprise any of the V described herein. H CDR and V L CDR. In some implementations, V H The CDR contains the amino acid sequences according to SEQ ID NO:7, SEQ ID NO:8, and SEQ ID NO:9. In some embodiments, V LThe CDR comprises or is composed of the amino acid sequences according to SEQ ID NO:10, SEQ ID NO:11, and SEQ ID NO:12. In some embodiments, the heavy chain and light chain may each comprise or be composed of one, two, three, four, five, six, seven, eight, nine, or ten conserved amino acid substitutions. In some embodiments, the heavy chain and light chain may each comprise or be composed of one, two, three, four, five, six, seven, eight, nine, or ten conserved amino acid substitutions outside the CDR.

[0079] In some embodiments, the antibody or its antigen-binding fragment is fully humanized. Fully human antibodies may be ideal for therapeutic treatment of human patients. Methods for generating fully human antibodies are known in the art, including phage display methods using antibody libraries derived from human immunoglobulin sequences (see U.S. Patents 4,444,887 and 4,716,111; and PCT disclosures WO 98 / 46645, WO 98 / 50433, WO 98 / 24893, WO 98 / 16654, WO 96 / 34096, WO 96 / 33735, and WO 91 / 10741). Human antibodies can also be generated using transgenic mice that do not express functional endogenous immunoglobulins but can express human immunoglobulin genes (see PCT disclosures WO 98 / 24893, WO92 / 01047, WO 96 / 34096, and WO 96 / 33735; and US patents 5,413,923, 5,625,126, 5,633,425, 5,569,825, 5,661,016, 5,545,806, 5,814,318, 5,885,793, 5,916,771, and 5,939,598). Fully human antibodies that recognize selected epitopes can also be generated using a technique known as “guided selection” (see Jespers et al., Biotechnology, 1988, 12, 899-903).

[0080] In some embodiments, the antibody or its antigen-binding fragment is a bispecific antibody. A bispecific antibody has binding specificity to at least two different antigens (i.e., one binding specificity is against BAI1, and the other binding specificity is against any other antigen, such as cell surface proteins, receptors, receptor subunits, tissue-specific antigens, virus-derived proteins, virus-encoded envelope proteins, bacterial-derived proteins, or bacterial surface proteins, etc.).

[0081] In some embodiments, the antibody or its antigen-binding fragment is a derived antibody. For example, a derived antibody can be an antibody modified by glycosylation, acetylation, polyethylene glycolation, phosphorylation, amidation, derivatization by known protecting / blocking groups, proteolytic cleavage, or linking to cellular ligands or other proteins. Any of many chemical modifications can be performed using known techniques, including but not limited to specific chemical cleavage, acetylation, formylation, and the metabolic synthesis of tunicamycin. Additionally, the derivative may contain one or more non-natural amino acids, such as those obtained using ambrx technology (see Wolfson, Chem. Biol., 2006, 13, 1011-1012).

[0082] In some embodiments, the antibody or its antigen-binding fragment is derived via glycosylation. A suitable dual-antenna complex may consist of a core structure having two N-acetylglucosamine (GlcNAc), three mannose residues, and two GlcNAc residues β-1,2 linked to α-6 mannose and α-3 mannose to form two antennas. One or more fucose (Fuc), galactose (Gal), high-mannan Man-5 or Man-9, bipartite GlcNAc, and sialic acid (including N-acetylneuraminic acid (NANA) or N-glycosidic neuraminic acid (NGNA) residues) may be attached to the core. N-linked glycoforms can include G0 (a protein with a core dual-antenna glycosylation structure), G0F (fucosylated G0), G0F GlcNAc, G1 (a protein with a core glycosylation structure containing one galactose residue), G1F (fucosylated G1), G2 (a protein with a core glycosylation structure containing two galactose residues), and / or G2F (fucosylated G2). In some embodiments, the anti-BAI1 antibody has a G0F glycan.

[0083] The antibody or its antigen-binding fragment can be prepared by recombinantly expressing immunoglobulin light and heavy chain genes in host cells. To recombinantly express the antibody, host cells are transfected with one or more recombinant expression vectors carrying DNA fragments encoding the immunoglobulin light and heavy chains of the antibody, causing the light and heavy chains to be expressed in the host cells and optionally secreted into the culture medium from which the antibody can be recovered. Standard recombinant DNA methods can be used to obtain the antibody heavy and light chain genes, incorporate these genes into a recombinant expression vector, and introduce the vector into host cells (see, Molecular Cloning; A Laboratory Manual, 2nd edition, edited by Sambrook, Fritsch, and Maniatis, Cold Spring Harbor, NY, 1989; Current Protocols in Molecular Biology, edited by Ausubel et al., Greene Publishing Associates, 1989; and U.S. Patent No. 4,816,397).

[0084] In some implementations, to generate nucleic acid molecules encoding antibodies or antigen-binding fragments thereof described herein, DNA fragments encoding the light and heavy chain variable regions are first obtained. These DNAs can be obtained by amplifying and modifying germline DNA or cDNA encoding the light and heavy chain variable sequences, for example, using polymerase chain reaction (PCR). Germline DNA sequences of human heavy and light chain variable region genes are known in the art (see, “VBASE” human germline sequence database; Kabat et al., 1991, Sequences of Proteins of Immunological Interest, 5th edition, USDapartment of Health and Human Services, NIH Publication No. 91-3242; Tomlinson et al., J. Mol. Biol., 1992, 22T, 116-198; and Cox et al., Eur. J. Immunol., 1994, 24, 827-836). DNA fragments encoding the variable regions of the heavy or light chains can be synthesized and used as templates for mutagenesis to generate the variants described herein using conventional mutagenesis techniques; alternatively, DNA fragments encoding the variants can be synthesized directly.

[0085] This disclosure provides V encoding an antibody or an antigen-binding fragment thereof. H A chain of isolated nucleic acid molecules, wherein the nucleic acid molecule comprises or is composed of the following nucleotide sequence: TCTGATGTGCAGCTTCAGGAGTCGG

[0086] GACCTGGCCTGGTGAAACCTTCTCAGTCTCTGTCCCTCACCTGCACTGTCACTGGCTACTCAATCACCAGTGATTATGCCTGGAACTGGATCCCGGCAGTTTCCAGGAAACAAACTGGAGTGGATGGGCTACATAAGCTACAGTGGTAGCACTAGCTACAACCCATC TCTCAAAAGTCGAATCTCTATCACTCGAGACACATCCAAGAACCAGTTCTTCCTGCAGTTGAATTCTGTGACTACTGAGGACACAGCCACATATTACTGTGCCAATGCCCAGGGGTTATGCTATGGACTACTGGGGTCAAGGAACCTCAGTCACCGTCTCCTCA(SEQ ID NO: 2; DNA) or UCUGAUGUGCAGCUUCAGGAGUCGGGACCUGGCCUGGU

[0087] GAAACCUUCUCAGUCUCUGUCCCUCACCUGCACUGUCACUGGCUACUCAAUCACCAGUGAUUAUGCCUGGAACUGGAUCCGGCAGUUUCCAGGAAACAAACUGGAGUGGAUGGGCUACAUAAGCUACAGUGGUAGCACUAGCUACAACCCAUCUCAAA AGUCGAAUCUCUAUCACUCGAGACACAUCCAAGAACCAGUUCUUCCUGCAGUUGAAUUCUGUGACUACUGAGGACACAGCCACAUAUUACUGUGCCAAUGCCCAGGGGUAUGCUAUGGACUACUGGGGUCAAGGAACCUCAGUCACCGUCUCCUCA(SEQ ID NO: 3; RNA).

[0088] This disclosure also provides V encoding an antibody or an antigen-binding fragment thereof. L A chain of isolated nucleic acid molecules, wherein the nucleic acid molecule contains or is composed of the following nucleotide sequence: GACATTGTGATGACTCAGT

[0089] CTCCAGCCACCCTGTCTGTGACTCCAGGAGATAGAGTCTCTCTTTCCTGCAGGGCCAGCCAGAGTATTAGCGACTACTTACACTGGTATCAACAAAAATCACATGAGTCTCCAAGGCTTCTCATCAAATATGCTTCCCAATCCATCTCTGGGA TCCCCTCCAGGTTCAGTGGCAGTGGATCAGGGTCAGATTTCACTCTCAGTATCAACAGTGTGGAACCTGAAGATGTTGGAGTGTATTACTGTCAAAATGGTCACAGCTTTCCATTCACGTTCGGCTCGGGGACAAAGTTGGAAATAAAA(SEQ ID NO:5,DNA) or GACAUUGUGAUG

[0090] ACUCAGUCUCCAGCCACCCUGUGUGACUCCAGGAGAUAGAGUCUCUUUCCUGCAGGGCCAGCCAGAGUAUUAGCGACUACUUACACUGGUAUCAACAAAAAUCACAUGAGUCUCCAAGGCUUCUCAUCAAAUAUGCUUCCCAAUCCAUCUCU GGGAUCCCCUCCAGGUUCAGUGGCAGUGGAUCAGGGUCAGAUUUCACUCUCAGUAUCAACAGUGUGGAACCUGAAGAUGUUGGAGUGUAUUACUGUCAAAAUGGUCACAGCUUUCCAUUCACGUUCGGCUCGGGGACAAAGUUGGAAAUAAAA(SEQ ID NO: 6, RNA).

[0091] These DNA fragments can be further manipulated using standard recombinant DNA techniques, for example, to convert variable region genes into full-length antibody chain genes, Fab fragment genes, or scFv genes. In these manipulations, the gene encoding V will be... H or V L The DNA fragment is operatively linked to another DNA fragment encoding a different protein (such as an antibody constant region or a flexible linker). As used in this text, the phrase "operatively linked" means that the two DNA fragments are linked such that the amino acid sequences encoded by the two DNA fragments remain within the frame.

[0092] By encoding V HThe DNA is operatively linked to another DNA molecule encoding the heavy chain constant region (CH1, CH2, CH3, and optionally CH4), thereby encoding V H The isolated DNA molecules from the region are converted into full-length heavy chain genes. The sequences of human heavy chain constant region genes are known in the art (see, Kabat et al., 1991, Sequences of Proteins of Immunological Interest, 5th ed., Department of Health and Human Services, NIH Publication No. 91-3242) and DNA fragments encompassing these regions can be obtained by standard PCR amplification. Heavy chain constant regions can be IgG1, IgG2, IgG3, IgG4, IgA, IgE, IgM, or IgD constant regions. In some embodiments, the heavy chain constant region is an IgG1 or IgG4 constant region. For Fab fragment heavy chain genes, encoding V... H The DNA can be operatively linked to another DNA molecule that encodes only the CH1 constant region of the heavy chain.

[0093] By encoding V L DNA and encoding the light chain constant region C L Another DNA molecule can be operatively linked to encode V L The isolated DNA from the region is converted into a full-length light chain gene (and a Fab light chain gene). The sequences of human light chain constant region genes are known in the art (see, Kabat et al., 1991, Sequences of Proteins of Immunological Interest, 5th edition (USDepartment of Health and Human Services, NIH Publication No. 91-3242)) and DNA fragments covering these regions can be obtained by standard PCR amplification. Light chain constant regions can be κ or λ constant regions. In some embodiments, the light chain constant region is a κ constant region. To generate the scFv gene, the gene encoding V... H and V L The DNA fragment can be operatively linked to another fragment encoding a flexible linker, such as the amino acid sequence (Gly4Ser)3, so that V H and V L The sequence can be expressed as a continuous single-chain protein, where V H and V LThe regions are connected by flexible joints (see Bird et al., Science, 1988, 242, 423-426; Huston et al., Proc. Natl. Acad. Sci. USA, 1988, 85, 5879-5883; and McCafferty et al., Nature, 1990, 348, 552-554).

[0094] To express the antibodies or antigen-binding fragments described herein, DNA molecules encoding the partial or full-length light and heavy chains as described herein can be inserted into an expression vector, such that the gene is operatively linked to transcriptional and translational control sequences. In this context, the phrase "operatively linked" is intended to mean linking the antibody gene to a vector such that the transcriptional and translational control sequences in the vector perform their intended functions of regulating the transcription and translation of the antibody gene. Expression vectors and expression control sequences compatible with the host cells used for expression can be selected. The antibody light chain gene and antibody heavy chain gene can be inserted into separate vectors, or more typically, both genes can be inserted into the same expression vector.

[0095] Antibody genes can be inserted into expression vectors using standard methods, such as ligating the antibody gene fragment to a complementary restriction site on the vector, or blunt-end ligation if no restriction site is present. The expression vector may already carry the antibody constant region sequence before the light or heavy chain sequence is inserted. For example, V... H and V L One method to convert sequences into full-length antibody genes is to insert them separately into expression vectors that already encode the heavy chain constant region and the light chain constant region, thus enabling V... H C in the segment and carrier H The segments are operatively connected, while V L C in the segment and carrier L The segments are operatively linked. Alternatively, the recombinant expression vector can encode a signal peptide that promotes the secretion of the antibody chain from the host cell. The antibody chain gene can be cloned into the vector such that the signal peptide frame is linked to the amino terminus of the antibody chain gene. The signal peptide can be an immunoglobulin signal peptide or a heterologous signal peptide, such as a signal peptide derived from a non-immunoglobulin.

[0096] In addition to antibody chain genes, recombinant expression vectors can carry regulatory sequences that control the expression of antibody chain genes in host cells. Such regulatory sequences are described, for example, in Goeddel, Gene Expression Technology: Methods in Enzymology 185 (Academic Press, San Diego, Calif., 1990). Those skilled in the art will recognize that the design of expression vectors, including the selection of regulatory sequences, can depend on factors such as the choice of host cells to be transformed and the desired protein expression level. Suitable regulatory sequences for mammalian host cell expression include viral elements that direct high-level protein expression in mammalian cells, such as promoters and / or enhancers derived from cytomegalovirus (CMV) (such as CMV promoters / enhancers), simian virus 40 (SV40) (such as SV40 promoters / enhancers), adenoviruses (such as the adenovirus major late promoter (AdMLP)), and polyomaviruses. Viral regulatory elements and their sequences are known in the art (see, for example, U.S. Patent Nos. 5,168,062, 4,510,245, and 4,968,615).

[0097] The recombinant expression vectors disclosed herein may also carry additional sequences, such as sequences regulating vector replication in host cells (e.g., origin of replication) and selection marker genes. Selection marker genes facilitate the selection of host cells into which the vector has been introduced (see U.S. Patents 4,399,216, 4,634,665, and 5,179,017). Typically, for example, selection marker genes confer resistance to drugs such as G418, puromycin, isoprothiolane, hygromycin, or methotrexate to host cells into which the vector has been introduced. Suitable selection marker genes include dihydrofolate reductase (DHFR) genes (for DHFRs with methotrexate selection / amplification). - In host cells) and the neo gene (used for G418 selection). To express the light and heavy chains, expression vectors encoding the heavy and light chains are transfected into host cells using standard techniques. The various forms of the term "transfection" are intended to encompass a wide range of techniques commonly used to introduce exogenous DNA into prokaryotic or eukaryotic host cells, such as electroporation, lipid transfection, calcium phosphate precipitation, DEAE-glucan transfection, etc.

[0098] The antibody or its antigen-binding fragment can be expressed in prokaryotic or eukaryotic host cells. In some embodiments, expression of the antibody or its antigen-binding fragment can be performed in eukaryotic cells (such as mammalian host cells) to secrete properly folded and immunologically active antibodies. Exemplary mammalian host cells for expressing the recombinant antibodies or their antigen-binding fragments of this disclosure include Chinese hamster ovary (CHO) cells (including DHFR CHO cells (see, Urlaub, Proc. Natl. Acad. Sci. USA, 1980, 77, 4216-4220) (used with DHFR selection markers (see, Kaufman, Mol. Biol., 1982, 159, 601-621)), NSO myeloma cells, COS cells, 293 cells, and SP2 / 0 cells. When a recombinant expression vector encoding an antibody gene is introduced into a mammalian host cell, the antibody is produced by culturing the host cell for a period of time sufficient to allow the antibody to be expressed in the host cell or secreted into the culture medium in which the host cell is grown. The antibody or its antigen-binding fragment can be recovered from the culture medium using standard protein purification methods. Host cells can also be used to generate parts of the complete antibody, such as Fab fragments or scFv molecules. It should be understood that variations of the above procedure are within the scope of this disclosure. For example, it may be desirable to transfect host cells with DNA encoding the light or heavy chain (but not both) of the antibody described herein or its antigen-binding fragment.

[0099] Recombinant DNA technology can also be used to remove some or all of the DNA encoding one or both of the light and heavy chains that are not necessary for binding with BAI1. Molecules expressed by such truncated DNA molecules are also included in the antibodies or antigen-binding fragments described herein.

[0100] Alternatively, the disclosed antibody can be cross-linked with a second antibody using a standard chemical cross-linking method to generate a bifunctional antibody or its antigen-binding fragment, wherein one heavy chain and one light chain are the disclosed antibody, while the other heavy chain and light chain are specific to antigens other than BAI1. Bifunctional antibodies can also be prepared by expressing nucleic acids engineered to encode bifunctional antibodies.

[0101] For the recombinant expression of the antibodies or their antigen-binding fragments described herein, host cells can be co-transfected using the two expression vectors disclosed herein, with the first vector encoding a heavy-chain-derived polypeptide and the second vector encoding a light-chain-derived polypeptide. Typically, each of the two vectors contains a separate selection marker. Alternatively, a single vector encoding both heavy-chain and light-chain polypeptides can be used.

[0102] Once a nucleic acid encoding an antibody having the desired CDR sequence or one or more portions of its antigen-binding fragment is generated, further modifications can be introduced into the coding sequence, for example, to generate nucleic acids encoding antibodies with different CDR sequences, antibodies with reduced affinity for the Fc receptor, or antibodies of different subclasses.

[0103] The antibodies or antigen-binding fragments thereof described herein can also be produced by chemical synthesis (such as by the methods described in SolidPhase Peptide Synthesis, 2nd ed., 1984, The Pierce Chemical Co., Rockford, Ill). Variant antibodies or antigen-binding fragments thereof can also be produced using a cell-free platform (see, Chu et al., Biochemia, 2001, 2).

[0104] Once the antibody or its antigen-binding fragment described herein has been generated through recombinant expression, it can be purified using any method known in the art for the purification of immunoglobulin molecules, such as chromatography (e.g., ion exchange chromatography, affinity chromatography, particularly selective affinity chromatography for protein A, protein G, or protein L, and sizing column chromatography), centrifugation, differential dissolution, or any other standard technique for protein purification. Furthermore, the antibody or its antigen-binding fragment described herein may be fused with heterologous polypeptide sequences described herein or otherwise known in the art to facilitate purification.

[0105] Once separated, the antibody or its antigen-binding fragment can be further purified if needed, such as by high-performance liquid chromatography (see Fisher, Laboratory Techniques in Biochemistry and Molecular Biology (edited by Work and Burdon, Elsevier, 1980)), or by Superdex. TM 75-column gel filtration chromatography (Pharmacia Biotech AB, Uppsala, Sweden).

[0106] This disclosure provides vectors comprising any of the nucleic acid molecules described herein. This disclosure also provides vector-transformed prokaryotic host cells. This disclosure further provides vector-transformed eukaryotic host cells. In some embodiments, the eukaryotic host cells are mammalian host cells.

[0107] In some embodiments, the antibody or its antigen-binding fragment is conjugated to an effector moiety. In some embodiments, the antibody or its antigen-binding fragment is modified by covalent attachment of any type of molecule to the antibody or its antigen-binding fragment, such that the covalent attachment does not interfere with binding to BAI1. In some embodiments, the effector moiety is a detectable label, cytotoxic agent, chemotherapeutic agent, or nucleic acid molecule. The effector moiety may also be an antitumor agent, drug, toxin, bioactive protein (such as an enzyme), another antibody or antibody fragment, synthetic or naturally occurring polymer, nucleic acid molecule, radionuclide (such as radioiodide), radioisotope, chelated metal, nanoparticle, or reporter group (such as a fluorescent compound or a compound detectable by NMR or ESR spectroscopy).

[0108] In some embodiments, the antibody or its antigen-binding fragment may be partially conjugated to a cytotoxic agent, radionuclide, or drug to alter a specific biological response. The effector moiety may be a protein or polypeptide, such as toxins (e.g., absinthecin, ricin A, saponins, Pseudomonas exotoxin, diphtheria toxin, ethidium bromide, or PE40, PE38, white tree toxin, RNase, peptide nucleic acid (PNA), ribosome-inactivating protein (RIP) type 1 or 2, pokeweed antiviral protein (PAP), bryodin, bitter melon protein, chemotherapeutic agents, and bouganin); signaling molecules (e.g., α-interferon, β-interferon). Interferon, nerve growth factor, platelet-derived growth factor or tissue plasminogen activator; thrombotic agents or anti-angiogenic agents (such as angiostatin or endostatin) or biological response modifiers, such as cytokines or growth factors (such as interleukin-1 (IL-1), interleukin-2 (IL-2), interleukin-6 (IL-6), granulocyte-macrophage colony-stimulating factor (GM-CSF), granulocyte colony-stimulating factor (G-CSF) or nerve growth factor (NGF)).

[0109] In some embodiments, the cytotoxic agent is a small molecule, a prodrug, a maytansinoid, or a toxin. In some embodiments, the antibody or its antigen-binding fragment contains 3 to 5 maytansinoid molecules in each antibody or its antigen-binding fragment. In some embodiments, the maytansinoid is conjugated to the antibody or its antigen-binding fragment via a chemical linker selected from N-succinimidyl-3-(2-pyridyldithio)propionate, N-succinimidyl-4-(2-pyridylthio)valerate (SPP), and succinimidyl-4-(N-maleimidemethyl)cyclohexane-1-carboxylate. In some implementation schemes, the cytotoxic agents are paclitaxel, cytochalasin B, bacitracin D, ethidium bromide, emetine, mitomycin, etoposide, tenoposide, vincristine, vinblastine, colchicine, doxorubicin, daunorubicin, dihydroxyanthraquinone, mithramycin, and actinomycin D.

[0110] 1-Dehydrotestosterone, glucocorticoids, procaine, tetracaine, lidocaine, propranolol, or puromycin.

[0111] In some embodiments, the detectable label is a radioactive compound, a fluorescent compound, a chromophore, an enzyme, a developer, a metal ion, or a substrate. In some embodiments, the fluorescent portion includes, but is not limited to, fluorescein, fluorescein isothiocyanate, rhodamine, 5-dimethylamine-1-naphthalenesulfonyl chloride, phycoerythrin, etc. Useful enzyme labels include, but are not limited to, alkaline phosphatase, horseradish peroxidase, glucose oxidase, etc.

[0112] In some implementations, the effector component is an antimetabolite (such as methotrexate, 6-mercaptopurine, 6-thioguanine, cytarabine, and 5-fluorouracil decarbazine), an alkylating agent (such as nitrogen mustard, thioepa, chlorambucil, melphalan, carmustine (BSNU), and lomustine (CCNU), cyclophosphamide, busulfan, etc.), etc. (e.g., dibromomannitol, streptozotocin, mitomycin C5 and cis-dichlorodiamineplatin(II)(DDP)cisplatin), anthracycline antibiotics (such as daunorubicin (formerly known as doxorubicin) and doxorubicin), antibiotics (such as dermatomycin (formerly known as actinomycin), bleomycin, photomycin, ammoniated cytosine (AMC), calicheamicin or duocarmycin)) or antimitotic agents (such as vincristine and vinblastine).

[0113] In some implementations, the radionuclide is, but is not limited to, 13 N、 18 F, 32 P, 64 Cu、 66 Ga、 67 Ga、 68 Ga、 67 Cu、 77 Br、 80m Br、 82 Rb、 86 Y、 90 Y、 95 Ru、 97 Ru、 99m Tc, 103 Ru、 105 Ru、 111 In、 113m In、 113 Sn、 121m Te、 122m Te、 125m Te、 123 I, 124 I, 125 I, 126 I, 131 I, 133 I, 165 Tm、 167 Tm、 168 Tm、 177 Lu、 186 Re、 188 Re、 195mHg, 211 At、 212 Bi、 213 Bihe 225 Ac.

[0114] In some implementation schemes, the chemotherapy agents are cisplatin, carboplatin, oxaliplatin, nedaplatin, triplatin tetranitrate, phenanthriplatin, picoplatin, satraplatin, methotrexate, vincristine, doxorubicin, tunicamycin, oligomycin, bortezomib, and MG132.

[0115] 5-Fluorouracil, sorafenib, flavopiridol, gemcitabine, paclitaxel, mercaptopurine, thioguanine, hydroxyurea, cytarabine, mitomycin, cyclophosphamide, ifosfamide, nitrosourea, dacarbazine, procaine, etoposide, camptothecin, bleomycin, idarubicin, dactinomycin, distamycin A A) etidium, netropsin, auristatin, amsacrine, prodigiosin, bortezomib, pibenzimol, tomaymycin, plicamycin SA, mitoxantrone, asparaginase, vinblastine, vinorelbine, paclitaxel, docetaxel, CPT-11, gleevec, erlotinib, gefitinib, ibrutinib, crizotinib, ceritinib, lapatinib, navitoclax, or regorafenib.

[0116] In some implementations, the nucleic acid molecule is a monolayer nucleic acid carrier, a 1.5-layer nucleic acid carrier, a bilayer nucleic acid carrier, a 2.5-layer nucleic acid carrier, or a trilayer nucleic acid carrier (such as those disclosed in, for example, PCT disclosures WO 17 / 143156 and WO 17 / 143171).

[0117] The technique of conjugating such effector components with antibodies is well known in the art (see Hellstrom et al., Controlled Drug Delivery, 2nd ed., pp. 623-53 (edited by Robinson et al., 1987)); Thorpe et al., Immunol Rev., 1982, 62, 119-58; and Dubowchik et al., Pharmacology and Therapeutics, 1999, 83, 67-123).

[0118] In some embodiments, the antibody or its antigen-binding fragment may be fused to an amino acid sequence (or a portion thereof; for example, a portion of at least 10, 20, or 50 amino acids of the protein) of another protein via a covalent bond (such as a peptide bond), through the N-terminus or C-terminus of the antibody, or internally. The antibody or its antigen-binding fragment may be linked to another protein at the N-terminus of a constant domain of the antibody. Such fusions can be generated using recombinant DNA procedures, for example, as described in PCT Publication WO86 / 01533 and European Patent EP0392745. In some embodiments, the effector portion may increase the in vivo half-life of the antibody and / or enhance the delivery of the antibody across the epithelial barrier to the immune system. Examples of suitable effector portions of this type include polymers, albumins, albumin-binding proteins, or albumin-binding compounds, such as those described in PCT Publication WO 2005 / 117984.

[0119] In some embodiments, the antibody or its antigen-binding fragment may be conjugated to a small molecule toxin. In some embodiments, the antibody or its antigen-binding fragment may be conjugated to scabrain or scabrain peptide analogs or derivatives (such as auristatin) (see U.S. Patent Nos. 5,635,483 and 5,780,588). The scabrain or auristatin pharmaceutical moiety may be attached to the antibody via its N-terminus, C-terminus, or internally (see PCT Publication WO 02 / 088172). Exemplary auristatin embodiments include N-terminally linked monomethyl auristatin pharmaceutical moietys DE and DF, as disclosed in U.S. Patent No. 7,498,298 (which discloses linkers and methods for preparing monomethylvaline compounds, such as MMAE and MMAF conjugated to linkers).

[0120] Antibodies or their antigen-binding fragments can also be conjugated to liposomes for targeted delivery (see Park et al., Adv. Pharmacol., 1997, 40, 399-435; and Marty et al., Methods Molec. Med., 2004, 109, 389-401).

[0121] In some embodiments, the antibody or its antigen-binding fragment may be attached to a poly(ethylene glycol) (PEG) moiety. In some embodiments, the antibody or its antigen-binding fragment and the PEG moiety may be attached via any available amino acid side chain or terminal amino acid functional group located on the antibody or its antigen-binding fragment, such as any free amino, imino, thiol, hydroxyl, or carboxyl group. Such amino acids may be naturally present in the antibody or its antigen-binding fragment, or may be engineered into the fragment using recombinant DNA methods (see, U.S. Patent No. 5,219,996). Multiple sites may be used to attach two or more PEG moieties. The PEG moiety may be covalently linked via a thiol group located on at least one cysteine ​​residue in the antibody or its antigen-binding fragment. When the thiol group is used as an attachment site, a suitably activated effector moiety may be used, such as a thiol-selective derivative, such as maleimide and cysteine ​​derivatives.

[0122] In some embodiments, the antibody or its antigen-binding fragment may comprise a polyethylene glycol-modified Fab' fragment. The PEG portion may be attached to a cysteine ​​residue in the hinge region. In some embodiments, the PEG-modified Fab' fragment has a maleimide group covalently linked to a single thiol group in the modified hinge region. Lysine residues may be covalently linked to the maleimide group, and each amino group on the lysine residue may be attached to a methoxylated poly(ethylene glycol) polymer with a molecular weight of approximately 20,000 Da. Therefore, the total molecular weight of the PEG attached to the Fab' fragment is approximately 40,000 Da.

[0123] In some embodiments, the antigen-binding fragment may be Fab, F(ab')2, Fv, scFv, scFv-Fc, a double-chain antibody, or a microantibody fragment. In some embodiments, the antigen-binding fragment may be a Fab fragment. In some embodiments, the antigen-binding fragment may be an F(ab')2 fragment. In some embodiments, the antigen-binding fragment may be an Fv fragment. In some embodiments, the antigen-binding fragment may be an scFv fragment. In some embodiments, the antigen-binding fragment may be an scFv-Fc fragment. In some embodiments, the antigen-binding fragment may be a double-chain antibody fragment. In some embodiments, the antigen-binding fragment may be a microantibody fragment.

[0124] This disclosure also provides pharmaceutical compositions comprising the antibodies or antigen-binding fragments thereof described herein and a pharmaceutically acceptable carrier. In some embodiments, the pharmaceutical compositions further comprise a tonic agent, a surfactant, a preservative, and / or a buffer system with a pH of about 4.0 to about 8.0. In some embodiments, the pharmaceutical compositions further comprise one or more additional therapeutic agents, such as combination therapeutic agents described herein. In some embodiments, the pharmaceutical compositions are liquid pharmaceutical compositions.

[0125] In some embodiments, the pharmaceutical composition may be presented in unit dose form, each dose containing a predetermined amount of the antibody or its antigen-binding fragment described herein. Pharmaceutically acceptable carriers used in the pharmaceutical composition may take various forms, depending on the condition to be treated or the route of administration.

[0126] Pharmaceutical compositions containing the antibodies or antigen-binding fragments thereof described herein can be prepared into lyophilized formulations or aqueous solutions for storage by mixing an antibody or antigen-binding fragment of the desired purity with optional pharmaceutically acceptable carriers, excipients or stabilizers (all referred to herein as “carriers”), such as buffers, stabilizers, preservatives, isotonic agents, nonionic detergents, antioxidants and various other additives commonly used in the art.

[0127] Buffers help maintain pH values ​​within a range close to physiological conditions. They can be present at concentrations ranging from about 2 mM to about 50 mM. Suitable buffers used in the pharmaceutical compositions described herein may include organic and inorganic acids and their salts, such as citrate buffers (e.g., monosodium citrate-disodium citrate mixtures, trisodium citrate mixtures, monosodium citrate-citrate mixtures, etc.), succinate buffers (e.g., monosodium succinate-succinate mixtures, succinate-sodium hydroxide mixtures, succinate-disodium succinate mixtures, etc.), tartrate buffers (e.g., tartaric acid-sodium tartrate mixtures, tartaric acid-potassium tartrate mixtures, tartaric acid-sodium hydroxide mixtures, etc.), and fumarate buffers (e.g., fumaric acid-fumaric acid-sodium tartrate mixtures). Sodium buffers, fumarate-disodium fumarate mixtures, monosodium fumarate-disodium fumarate mixtures, etc.; gluconate buffers (such as gluconate-sodium gluconate mixtures, gluconate-sodium hydroxide mixtures, gluconate-potassium gluconate mixtures, etc.); oxalate buffers (such as oxalate-sodium oxalate mixtures, oxalate-sodium hydroxide mixtures, oxalate-potassium oxalate mixtures, etc.); lactate buffers (such as lactate-sodium lactate mixtures, lactate-sodium hydroxide mixtures, lactate-potassium lactate mixtures, etc.); and acetate buffers (such as acetate-sodium acetate mixtures, acetate-sodium hydroxide mixtures, etc.). Additionally, phosphate buffers, histidine buffers, and trimethylamine salts, such as Tris, can be used.

[0128] Preservatives may be added to pharmaceutical compositions to reduce microbial growth, and may be added in amounts ranging from about 0.2% to about 1% (w / v). Suitable preservatives for use with the pharmaceutical compositions described herein include, but are not limited to, phenol, benzyl alcohol, m-cresol, methylparaben, propylparaben, octadecyl dimethyl benzyl ammonium chloride, benzalkonium chloride (such as chloride, bromide, and iodide), hexamethyl diammonium chloride, and alkylparabens such as methylparaben or propylparaben, catechol, resorcinol, cyclohexanol, and 3-pentanol.

[0129] Isotonic agents, sometimes called "stabilizers," can be added to ensure the isotonicity of liquid compositions. These are polyols, such as triols or higher sugar alcohols, including glycerol, erythritol, arabinitol, xylitol, sorbitol, and mannitol. Stabilizers refer to a broad class of excipients whose functions range from fillers to dissolving agents or additives that help prevent denaturation or adhesion to container walls. Typical stabilizers can be polyols (listed above); amino acids, such as arginine, lysine, glycine, glutamine, asparagine, histidine, alanine, ornithine, L-leucine, 2-phenylalanine, glutamic acid, threonine, etc.; organic sugars or sugar alcohols, such as lactose, trehalose, stachyose, mannitol, sorbitol, xylitol, ribitol, inositol, galactitol, glycerol, etc., including cyclic polyols such as inositol; polyethylene glycol; amino acid polymers; and sulfur-containing reducing agents. Stabilizers, such as urea, glutathione, lipoic acid, sodium thioglycolate, thioglycerol, α-monothioglycerol, and sodium thiosulfate; low molecular weight peptides (such as peptides with 10 residues or fewer); proteins, such as human serum albumin, bovine serum albumin, gelatin, or immunoglobulins; hydrophilic polymers, such as polyvinylpyrrolidone monosaccharides, such as xylose, mannose, fructose, and glucose; disaccharides such as lactose, maltose, and sucrose; and trisaccharides such as raffinose; and polysaccharides such as dextran. Stabilizers may be present in the range of about 0.1 to about 10,000 parts by weight per part by weight of active protein.

[0130] Nonionic surfactants or detergents (also known as "wetting agents") can also be added to pharmaceutical compositions to help dissolve antibodies or their antigen-binding fragments, and to protect the antibodies or their antigen-binding fragments described herein from agitation-induced aggregation. This also allows the formulation to be exposed to shear surface stress without causing protein denaturation. Suitable nonionic surfactants include polysorbates (20, 80, etc.), poloxamer (184, 188, etc.), Pluronic polyols, and polyoxyethylene dehydrated sorbitol monoether (TWEEN). TM -20, TWEEN TM-80, etc.). Nonionic surfactants may be present in the range of about 0.05 mg / mL to about 1.0 mg / mL, for example, about 0.07 mg / mL to about 0.2 mg / mL.

[0131] Additional excipients, such as fillers (e.g., starch), chelating agents (e.g., EDTA), antioxidants (e.g., ascorbic acid, methionine, and vitamin E), and solubilizers, may also be added to the pharmaceutical composition.

[0132] This disclosure also provides pharmaceutical kits containing antibodies or antigen-binding fragments thereof (including antibody conjugates) described herein. The pharmaceutical kit may be a package containing antibodies or antigen-binding fragments thereof described herein (e.g., in lyophilized or aqueous form) and one or more of the following: a combination therapy, a device for administering the antibody or antigen-binding fragment, such as a pen, needle, and / or syringe; and pharmaceutical-grade water or buffer for resuspending the antibody or antigen-binding fragment (if the antibody is in lyophilized form).

[0133] In some embodiments, each unit dose of the antibody or its antigen-binding fragment is individually packaged, and the kit may contain one or more unit doses (e.g., two unit doses, three unit doses, four unit doses, five unit doses, eight unit doses, ten unit doses, or more unit doses). In some embodiments, the one or more unit doses are each contained in a syringe or pen.

[0134] This document also covers diagnostic kits containing antibodies or antigen-binding fragments thereof (including antibody conjugates) described herein. A diagnostic kit may be a package containing antibodies or antigen-binding fragments thereof described herein (e.g., in lyophilized or aqueous form) and one or more reagents that can be used to perform diagnostic assays. In cases where the antibody or antigen-binding fragment is enzyme-labeled, the kit may include substrates and cofactors required for the enzyme (e.g., providing substrate precursors for detecting chromophores or fluorophores). Additionally, other additives may be included, such as stabilizers, buffers (e.g., blocking buffers or lysis buffers), etc. In some embodiments, the antibody or antigen-binding fragment included in the diagnostic kit may be immobilized on a solid surface, or the diagnostic kit may include a solid surface (such as a glass slide or plate) on which the antibody or antigen-binding fragment may be immobilized. The relative amounts of various reagents may be varied to provide reagent concentrations in solution that significantly optimize assay sensitivity. In some embodiments, the antibody or antigen-binding fragment, along with one or more reagents, may be provided in dry powder form (alone or in combination), typically lyophilized, including excipients that provide a reagent solution with an appropriate concentration upon dissolution.

[0135] This disclosure also provides a method for detecting cells expressing BAI1, the method comprising contacting the cells with an antibody or an antigen-binding fragment thereof described herein, and detecting the antibody or the antigen-binding fragment thereof. In some embodiments, the cells are present in a biological sample obtained from a human, and the cells are contacted with the antibody or the antigen-binding fragment thereof in vitro. In some embodiments, the cells are present in a human, and the cells are contacted with the antibody or the antigen-binding fragment thereof in vivo.

[0136] In some embodiments, the antibody or antigen-binding fragment described herein has a high binding affinity for BAI1. In some embodiments, the antibody or antigen-binding fragment has a specific association rate constant (k). on or k A value), dissociation rate constant (k off or k D (value), affinity constant (K) A value), dissociation constant (K) D (value) and / or IC 50 value.

[0137] In some embodiments, the antibody or its antigen-binding fragment binds to BAI1, whose K A (k on / k off (at least about 10) 10 M -1 At least approximately 4×10 11 M -1 At least about 10 11 M -1 At least approximately 4×10 12 M -1 At least about 10 12 M -1 At least approximately 4×10 13 M -1 At least about 10 13 M -1 At least approximately 4×10 14 M -1 At least about 10 14 M -1 At least approximately 4×10 15 M -1 Or at least about 10 15 M -1 or its K A It has any range from any pair of the aforementioned values ​​to any pair of the aforementioned values ​​(e.g., approximately 4 × 10⁻⁶). 11 M -1 To approximately 4×10 13 M -1 Or approximately 4×10 12 M -1To approximately 4×10 15 M -1 ).

[0138] In some embodiments, the antibody or its antigen-binding fragment binds to BAI1, whose K D (k off / k on (approximately 10) -10 Or lower, approximately 4×10 -11 M or lower, approximately 10 -11 M or lower, approximately 4×10 -12 M or lower, approximately 10 -12 M or lower, approximately 4×10 13 M or lower, approximately 10 -13 M or lower, approximately 4×10 14 M or lower, approximately 10 -14 M or lower, approximately 4×10 -15 M or lower or around 10 -15 M or lower, or its K D It has any range from any pair of the aforementioned values ​​to any pair of the aforementioned values ​​(e.g., approximately 4 × 10⁻⁶). - 11 M to approximately 4 × 10 -13 M or approximately 4 × 10 -12 M to approximately 4 × 10 -15 M).

[0139] In some implementation schemes, K D (k off / k on The value is determined by methods well-known in the art, such as ELISA, isothermal titration calorimetry (ITC), fluorescence polarization assay, or any other biosensor, such as BIAcore.

[0140] In some embodiments, the antibody or its antigen-binding fragment binds to BAI1 and inhibits the binding of BAI1 to its ligand, with an IC50 value of 100%. 50 Less than approximately 0.02 nM, less than approximately 0.01 nM, less than approximately 0.005 nM, less than approximately 0.002 nM, less than approximately 0.001 nM, less than approximately 5 × 10 -4 nM, less than approximately 2 × 10 -4 nM, less than approximately

[0141] 1×10 -4 nM, less than approximately 5 × 10 -5 nM, less than approximately 2 × 10 -5 nM, less than approximately 1×10 -4 nM, less than approximately 5 × 10 - 6nM, less than approximately 2 × 10 -6 nM, less than approximately 1×10 -6 nM, less than approximately 5 × 10 -7 nM, less than approximately 2 × 10 -7 nM or less than about 1×10 -7 nM, or its IC 50 Any range from any of the aforementioned values ​​to any of the aforementioned values ​​(e.g., about 0.02 nM to about 2 × 10⁻⁶). - 5 nM or approximately 5 × 10 -5 nM to approximately 1×10 -7 nM). IC 50 It can be measured using methods well-known in the art, such as ELISA.

[0142] The antibodies or antigen-binding fragments thereof, including those that have been modified, such as by biotinylation, horseradish peroxidase, or any other detectable portion (including those mentioned above), may be used for diagnostic purposes.

[0143] In some embodiments, the antibody or its antigen-binding fragment can be used to purify or detect BAI1, including in vitro and in vivo diagnostic methods. For example, the antibody or its antigen-binding fragment can be used in immunoassays to qualitatively and quantitatively measure BAI1 levels in biological samples, or to identify the location, quantity, behavior, and / or similar properties of BAI1 in animals. For example, measuring BAI1 levels using the antibody or its antigen-binding fragment described herein can be used, for example: 1) to diagnose or determine an increased risk of developing cancer in a patient, 2) to determine a patient's prognosis, including tumor stage and grade (particularly whether the cancer is metastatic or likely to be metastatic) and / or its potential sensitivity to BAI1 therapy, 3) to determine the origin of the tumor, and / or 4) to determine the efficacy of treatment in a patient.

[0144] In some embodiments, the antibody or its antigen-binding fragment can, for example, be combined with a compound screening assay to evaluate the effect of an agent on the expression and / or activity of the BAI1 gene product. Additionally, the antibody or its antigen-binding fragment can be used in conjunction with gene therapy techniques to, for example, evaluate the success of transfection for normal and / or engineered BAI1 expression.

[0145] This disclosure also provides methods for diagnosing neurological diseases, comprising detecting the amount or activity of BAI1 expressed in neural tissue or any tissue associated with non-CNS target organs, such as the lungs, liver, kidneys, spleen, etc. The diagnostic method may employ an antibody or an antigen-binding fragment thereof conjugated to a diagnostic agent. The antibody or antigen-binding fragment thereof may be used for diagnosis, for example, detecting the expression of BAI1 in specific cells, tissues, or serum; or monitoring the development or progression of an immune response as part of a clinical testing procedure to, for example, determine the efficacy of a specific treatment regimen. Detection can be facilitated by conjugating the antibody or its antigen-binding fragment to a detectable substance. Examples of detectable substances include, but are not limited to, various enzymes, prosthetic groups, fluorescent materials (such as fluorescein and rhodamine and their derivatives), luminescent materials, bioluminescent materials, optical reagents (such as porphyrins, anthraquinones, anthraquinones, perylenequinones, xanthannes, anthocyanins, acridines, phenoxazines, and phenothiazines), radioactive materials, positron-emitting metals using various positron emission tomography techniques, and non-radioactive paramagnetic metal ions (such as Gd(III), Eu(III), Dy(III), Pr(III), Pa(IV), Mn(II), Cr(III), Co(III), Fe(III), Cu(II), Ni(II), Ti(III), and V(IV)). Detectable substances can be directly conjugated or conjugated to antibodies or their antigen-binding fragments, or indirectly conjugated or conjugated via intermediates (e.g., linkers known in the art) using techniques known in the art. Examples of enzyme-labeled enzymes include luciferases (such as firefly luciferase and bacterial luciferase; see, U.S. Patent No. 4,737,456), luciferin, 2,3-dihydrophthalazinedione, malate dehydrogenase, urease, peroxidases (such as horseradish peroxidase (HRPO)), alkaline phosphatase, β-galactosidase, acetylcholinesterase, glucosylamylase, lysozyme, sugar oxidases (such as glucose oxidase, galactose oxidase, and glucose-6-phosphate dehydrogenase), heterocyclic oxidases (such as uricase and xanthine oxidase), lactoperoxidase, microperoxidase, etc. Examples of suitable cofactor complexes include, but are not limited to, streptavidin / biotin and avidin / biotin; examples of suitable fluorescent materials include, but are not limited to, umbelliferone, luciferin, luciferin isothiocyanate, rhodamine, dichlorotriazineamine luciferin, dansyl chloride, or phycoerythrin; examples of luminescent materials include luminol; examples of bioluminescent materials include, but are not limited to, luciferase, luciferin, and jellyfish luminescent protein; and examples of suitable radioactive materials include, but are not limited to, […]. 125 I, 131 I, 111 In or 99 Tc.

[0146] This disclosure also provides a method for detecting BAI1 expression on cells, comprising contacting a biological sample from a patient with one or more antibodies described herein or antigen-binding fragments thereof (optionally conjugated to a detectable portion) and detecting whether the sample is positive for BAI1 expression or whether the sample has altered (e.g., reduced or increased) expression compared to a control sample. Biological samples may include biopsies of various tissues, including but not limited to: skin, muscle, breast, prostate, cervix, ovary, brain, testis, and lungs. Examples of cells in biological samples include tumor cells, skin cells, muscle cells, blood cells, ovarian cells, brain cells, prostate cells, breast cells, testicular cells, cervical cells, and lung cells. Biological samples may also be biological fluids.

[0147] The presence of BAI1-expressing cells in biological samples indicates the presence of cancer and can indicate metastasis, especially when their numbers are greater than those in healthy subjects. Over time, a loss of BAI1-expressing cells in patients (particularly those undergoing treatment) indicates disease remission (i.e., treatment success), while no change in BAI1-expressing cell levels in treated patients indicates resistance to the therapy and suggests the possibility of a different treatment strategy. Similarly, an increase in BAI1-expressing cells in patients over time can indicate recurrence. Additionally, the imaging techniques described herein can be used to monitor tumor size to determine the efficacy of treatment. In some embodiments, other cancer diagnostic assays can be performed to confirm the results obtained using the methods described herein.

[0148] In some implementations, biological samples (such as tumor samples) can be obtained from the subject, and the presence of cells expressing BAI1 can be determined. The number of cells expressing BAI1 can be correlated with tumor grade. In some implementations, the number of cells expressing BAI1 in the biological sample is compared with the number of cells expressing BAI1 in a corresponding biological sample from a healthy individual to determine the regulation of BAI1-expressing cells in the tumor. Subjects with tumors can be treated with pharmaceutical agents to regulate the activity of BAI1-expressing cells to normal, healthy levels.

[0149] Diseases that can be diagnosed using the methods of this invention include, but are not limited to, cancers of the nervous system, such as primary brain tumors, including gliomas (glioblastomas), meningiomas, schwannomas, pituitary adenomas, medulloblastomas, craniopharyngiomas, hemangiomas, epidermoid tumors, sarcomas, and intracranial metastases from other tumor sources. In some embodiments, the antibodies described herein or their antigen-binding fragments can be used to diagnose glioblastoma multiforme (GBM).

[0150] This disclosure also provides a method for treating cancers expressing BAI1, the method comprising administering to a patient in need of the antibody described herein or an antigen-binding fragment thereof. In some embodiments, the method involves administering to a patient with a solid tumor a specific amount of the antibody described herein or an antigen-binding fragment thereof to provide therapeutic benefit.

[0151] In some embodiments, the antibodies or antigen-binding fragments described herein can be administered to patients via a variety of routes, such as oral, percutaneous, subcutaneous, intranasal, intravenous, intraarterial, intramuscular, intraocular, topical, local, intrathecal, intraventricular, intraspinal, and intracranial. In any given case, the most suitable route of administration will depend on the specific antibody, the subject, the nature and severity of the disease, and the subject's physical condition. In some embodiments, the antibodies or antigen-binding fragments may be formulated as an aqueous solution. In some embodiments, the antibodies or antigen-binding fragments may be administered intravenously or intracranially.

[0152] The antibodies or antigen-binding fragments thereof described herein can be used to treat various BAI1-expressing growths. In some embodiments, the antibodies or antigen-binding fragments thereof described herein can be used to treat BAI1-expressing cancers, such as sarcomas with skeletal muscle characteristics and skin tumors. In some embodiments, the antibodies or antigen-binding fragments thereof described herein can be used to treat BAI1-expressing neurological cancers in patients, such as brain tumors or small brain lesions, such as micrometastases. In some embodiments, the BAI1-expressing cancer is a neurological cancer. In some embodiments, the neurological cancer is a primary brain tumor, glioblastoma, glioma, meningioma, schwannoma, pituitary adenoma, medulloblastoma, craniopharyngioma, hemangioma, epidermoid tumor, sarcoma, or intracranial metastases from other tumor sources. In some embodiments, the neurological cancer is glioblastoma. In some embodiments, the glioblastoma is glioblastoma multiforme (GBM).

[0153] In some embodiments, the brain tumor expressing BAI1 is a GBM tumor containing GBM tumor-initiating cells. In some embodiments, treatment with the antibody or antigen-binding fragment thereof described herein causes inhibition of GBM tumor-initiating cell proliferation. In some embodiments, the antibody or antigen-binding fragment thereof also inhibits the self-renewal of GBM tumor-initiating cells. Inhibition of cell proliferation and / or self-renewal can lead to improvement in signs or symptoms of the disease. For example, such therapy can cause an increase in survival (overall survival and / or progression-free survival) and / or can cause an objective clinical response (partial or complete). In some embodiments, the antibody or antigen-binding fragment thereof is internalized by GBM tumor cells, causing an increase in the therapeutic efficacy of the antibody or antigen-binding fragment thereof in killing the GBM tumor cells to which it is bound. In some embodiments, the antibody or antigen-binding fragment thereof acts as an antagonist of BAI1 biological activity and can also be used as a method for inhibiting aberrant BAI1 activity.

[0154] In some embodiments, the antibody or its antigen-binding fragment can be used to treat non-nervous systemic tumors expressing BAI1, including cancers and benign tumors. Cancers readily treatable with the antibodies or their antigen-binding fragments described herein include cancers overexpressing BAI1. In some embodiments, cancers readily treatable with the antibodies or their antigen-binding fragments described herein include epithelial cell carcinoma. In some embodiments, cancers readily treatable with the antibodies or their antigen-binding fragments described herein include, but are not limited to, breast cancer, ovarian cancer, lung cancer, colorectal cancer, anal cancer, prostate cancer, kidney cancer, bladder cancer, head and neck cancer, ovarian cancer, pancreatic cancer, skin cancer, oral cancer, esophageal cancer, vaginal cancer, cervical cancer, spleen cancer, testicular cancer, thymic cancer, head and neck cancer, and colorectal cancer. The cancer may be newly diagnosed and untreated, or may be recurrent, refractory, or recurrent and refractory, or a metastatic form of a solid tumor.

[0155] In some implementations, the antibodies or antigen-binding fragments described herein may be used to treat hematologic malignancies expressing BAI1, including but not limited to myeloma (such as multiple myeloma), lymphoma (such as Hodgkin's lymphoma, non-Hodgkin's lymphoma, Waldenström macroglobulinemia). Macroglobulinemia and mantle cell lymphoma), leukemias (such as chronic lymphocytic leukemia, acute myeloid leukemia, and acute lymphoblastic leukemia), and myelodysplastic syndromes. In some embodiments, the method includes administering the antibody described herein or an antigen-binding fragment thereof to a patient with a hematologic malignancy to provide therapeutic benefit.

[0156] In some implementations, the administration of the antibody or antigen-binding fragment thereof described herein is repeated after one day, two days, three days, five days, one week, two weeks, three weeks, one month, five weeks, six weeks, seven weeks, eight weeks, two months, or three months. Repeated administration may be at the same dose or at different doses. Administration may be repeated once, twice, three times, four times, five times, six times, seven times, eight times, nine times, ten times, or more. For example, depending on certain dosing regimens, patients may receive prolonged anti-BAI1 therapy, such as for six months, one year, or longer. The amount of the antibody or antigen-binding fragment thereof described herein administered to the patient is a therapeutically effective amount. As used herein, a “therapeuticly effective” amount of the antibody or antigen-binding fragment thereof described herein may be administered as a single dose or during a treatment regimen, such as over a period of one week, two weeks, three weeks, one month, three months, six months, one year, or longer. Exemplary treatment regimens are further described herein. Treatment of disease encompasses the treatment of patients diagnosed with any form of disease at any clinical stage or presentation; the delay of the onset, evolution, aggravation, or worsening of disease symptoms or signs; and / or prevention and / or mitigation of the severity of the disease.

[0157] Treating a patient’s cancer with the antibodies or antigen-binding fragments described herein may produce any proven clinical benefit compared to no treatment (where appropriate) or to known standards of care. Clinical benefit can be assessed by any method known to a person skilled in the art. In some embodiments, clinical benefit is assessed based on objective response rate (ORR) (determined using RECIST version 1.1), duration of response (DOR), progression-free survival (PFS), and / or overall survival (OS). In some embodiments, a complete response indicates a treatment benefit. In some embodiments, a partial response indicates a treatment benefit. In some embodiments, stable disease indicates a treatment benefit. In some embodiments, an increase in overall survival indicates a treatment benefit. In some embodiments, a treatment benefit may include improvement in time to disease progression and / or improvement in symptoms or quality of life. In some embodiments, a treatment benefit may not translate into an increase in disease control but may significantly reduce the burden of symptoms, resulting in an improvement in quality of life. As will be apparent to those skilled in the art, treatment benefit can be observed using the antibodies or antigen-binding fragments described herein alone (monotherapy) or in combination with other anticancer therapies and / or targeted or non-targeted anticancer agents, either adjuvant or in combination.

[0158] In some implementations, the benefit of treatment may be assessed using standard clinical trials designed to measure response to new cancer therapies. To assess the therapeutic benefit of the antibodies or their antigen-binding fragments described herein, one or a combination of the following trials may be used: 1) Evaluation Criteria for Solid Tumor Response (RECIST) version 1.1; 2) Immune-Related RECIST (irRECIST); 3) Eastern Cooperative Oncology Group (ECOG) activity status; 4) Immune-Related Response Criteria (irRC); 5) Disease evaluable by assessment of tumor antigens; 6) Validated patient-reported outcome scales; and / or 7) Kaplan-Meier estimates of overall survival and progression-free survival.

[0159] This disclosure also provides a combination therapy method comprising administering to a patient at least two agents, the first being an antibody or antigen-binding fragment thereof described herein, and the second being a combination therapy agent. The antibody or antigen-binding fragment thereof described herein and the combination therapy agent may be administered simultaneously, sequentially, or individually. The combination therapy method can produce an effect greater than the sum of its components.

[0160] In the method of this invention, the antibodies or antigen-binding fragments thereof described herein and the combination therapeutic agents can be administered concurrently, simultaneously, or sequentially. If the antibodies or antigen-binding fragments thereof described herein and the combination therapeutic agents are administered to a patient on the same day (e.g., during the same patient visit), they are administered sequentially. Sequential administration can be performed at intervals of 1, 2, 3, 4, 5, 6, 7, or 8 hours. Conversely, if the antibodies or antigen-binding fragments thereof described herein and the combination therapeutic agents are administered to a patient on different days, they are administered individually, for example, at intervals of 1 day, 2 or 3 days, 1 week, 2 weeks, or monthly. In the method of this disclosure, the administration of the antibodies or antigen-binding fragments thereof described herein can be before or after the administration of the combination therapeutic agent. In some embodiments, the antibodies or antigen-binding fragments thereof described herein and the combination therapeutic agents can be administered concurrently for a period of time, followed by alternating administration of the antibodies or antigen-binding fragments thereof and the combination therapeutic agent for a second period of time.

[0161] In some embodiments, the combination therapy is a chemotherapy agent, an anti-angiogenic agent, an antirheumatic drug, an anti-inflammatory agent, a radiotherapy agent, an immunosuppressant, or a cytotoxic agent. The antibodies or antigen-binding fragments thereof described herein may be used in combination with conventional cancer therapies such as surgery, radiotherapy, chemotherapy, or combinations thereof. In some embodiments, the method further includes surgical resection of tumor cells and / or administration of one or both of radiotherapy. In some embodiments, other therapeutic agents that can be used in combination with the antibodies or antigen-binding fragments thereof for cancer therapy include antagonists of other factors involved in tumor growth (such as HER2, HER3, HER4, VEGF, or TNF-α), such as antibodies. In some embodiments, administration of one or more cytokines to the patient may also be beneficial for cancer treatment. In some embodiments, the antibodies or antigen-binding fragments thereof described herein are co-administered with growth inhibitors.

[0162] For the treatment of cancer, anti-inflammatory agents may be used in combination with the antibodies or their antigen-binding fragments described herein. Anti-inflammatory agents include, but are not limited to, acetaminophen, diphenhydramine, meperidine, dexamethasone, pentamethasone, mesalazine, asacol, codeine phosphate, benorylate, fenbufen, naproxen, diclofenac, etodolac, indomethacin, aspirin, and ibuprofen.

[0163] For the treatment of cancer, chemotherapy agents can be used in combination with antibodies or their antigen-binding fragments as described herein. Chemotherapy agents include, but are not limited to, radioactive molecules, toxins (such as cytotoxic agents or cytotoxic agents), including any agent harmful to cell viability, agents containing chemotherapeutic compounds, and liposomes or other vesicles. Examples of suitable chemotherapy agents include, but are not limited to, 1-dehydrotestosterone,

[0164] 5-Fluorouracil aminopyrimidine, 6-mercaptopurine, 6-thioguanine, actinomycin D, doxorubicin, aldehyde-interleukin, anti-α5β1 integrin antibody, alkylating agents, allopurinol sodium, hexamethylmelamine, amifostine, anastrozole, amiodarone (AMC), antimitotic agents, cis-dichlorodiamineplatin(II) (DDP), cisplatin, diaminodichloroplatinum, anthracycline antibiotics, antibiotics, antimetabolites, asparaginase, live BCG (BCG) (intravesical), betamethasone sodium phosphate and betamethasone acetate, bicalutamide, bleomycin sulfate, busulfan, calcium leucovorin (calcium) Leucouorin, calicimycin, capecitabine, carboplatin, lomustine (CCNU), carmustine (BSNU), chlorambucil, cisplatin, cladribine, colchicine, conjugated estrogens, cyclophosphamide, cyclothioprine, cytarabine, cytarabine, cytochalasin B, cytoxan, dacarbazine, actinomycin D, actinomycin D (formerly known as actinomycin), daunorubicin, donomycin citrate, denileukin diftitox, dexrazoxane, dibromomannitol, dihydroxyanthracin dione, docetaxel, dolasetron mesylate mesylate, doxorubicin, dronabinol, Escherichia coli L-asparaginase, eolociximab, emetine, epoetin-α, Erwinia L-asparaginase, esterified estrogen, estradiol, estradiol phosphate, ethinyl estradiol, etidronate, etoposide citrororum Factor), etoposide phosphate, filgrastim, fluxuridine, fluconazole, fludarabine phosphate, fluorouracil, flutamide, leucovorin, gemcitabine, glucocorticoids, goserelin acetate, bacitracin D, granisetron, hydroxyurea, idarubicin, ifosfamide, interferon alpha-2b, irinotecan, letrozole, calcium leucovorin, leuprolide acetateAcetate), levamisole, lidocaine, lomustine, maytansine alkaloids, dichloromethyldiethylamine, medroxyprogesterone acetate, megestrol acetate, melphalan, mercaptopurine, mesna, methotrexate, methyltestosterone, photomycin, mitomycin C, mitotane, mitoxantrone, nilumethicone, octreotide acetate, ondansetron, paclitaxel, disodium pamidronate, pentostatin, pirocarpine, plimycin, polyphenylpropionate 20 with carmustine implants, porphyrin sodium, procaine The method may include, but is not limited to, procarbazine, propranolol, rituximab, sargramostim, streptozotocin, tamoxifen, paclitaxel, teniposide, testolactone, tetracaine, thioguanine, thiotepa, topotecan, toremifene citrate, trastuzumab, tretinoin, valrubicin, vinblastine sulfate, vincristine sulfate, and vinorelbine tartrate, or any salts thereof. In some embodiments, the method comprises administering at least one chemotherapeutic agent to the patient.

[0165] Any anti-angiogenic agent may be used in conjunction with the antibody or its antigen-binding fragment described herein. In some embodiments, the anti-angiogenic agent is a VEGF antagonist or another VEGF receptor antagonist, such as a VEGF variant, a soluble VEGF receptor fragment, an aptamer capable of blocking VEGF or VEGFR, a neutralizing anti-VEGFR antibody, a low molecular weight inhibitor of VEGFR tyrosine kinase, and any combination thereof. Alternatively, or additionally, an anti-VEGF antibody may be co-administered to the patient.

[0166] The treatment regimen administered to the patient can vary depending on the patient's age, weight, and disease condition. Treatment regimens can last from 2 weeks to indefinitely. In some implementations, the treatment regimen may last from approximately 2 weeks to approximately 6 months, from approximately 3 months to approximately 5 years, from approximately 6 months to approximately 1 year, or from approximately 2 years, or from approximately 8 months to approximately 18 months. The treatment regimen can be a fixed-dosing regimen or a multi-variable-dosing regimen.

[0167] The dosage of the antibody or its antigen-binding fragment described herein may depend on a variety of factors, including but not limited to the specific type of solid tumor being treated, the stage of the solid tumor being treated, the route of administration, the frequency of administration, the desired therapeutic benefit, and other parameters such as the patient's age, weight, and other characteristics. Determining the effective dose for a specific route of administration and frequency of administration to provide therapeutic benefit is within the capabilities of those skilled in the art. An effective dose to provide therapeutic benefit can be initially estimated from in vivo animal models or clinical trials. Animal models suitable for a variety of diseases are known in the art. The antibody or its antigen-binding fragment described herein may be administered via any route appropriate to the condition to be treated.

[0168] In some embodiments, the antibodies or antigen-binding fragments thereof described herein are provided as lyophilized powder in vials. The vials may contain about 100 mg, about 125 mg, about 150 mg, about 200 mg, about 250 mg, about 300 mg, or about 400 mg of the antibody or antigen-binding fragments thereof. Prior to administration, the lyophilized powder can be reconstituted with sterile water for injection (SWFI) or other suitable media to provide a solution containing the antibodies or antigen-binding fragments thereof described herein. In some embodiments, the resulting reconstituted solution is further diluted with saline or other suitable infusion media and administered via, for example, IV infusion, twice every 7 days, once every 7 days, once every 14 days, once every 21 days, once every 28 days, once every 35 days, once every 42 days, once every 49 days, or once every 56 days. In some embodiments, for the first cycle, the infusion occurs within 90 minutes. In some embodiments, subsequent infusions occur within 60 minutes.

[0169] In some embodiments, the antibody or antigen-binding fragment described herein is administered as an IV infusion every 7 days at a dose of about 0.1 mg / kg, about 0.5 mg / kg, about 1.0 mg / kg, about 2.0 mg / kg, about 3.0 mg / kg, about 4.0 mg / kg, about 5.0 mg / kg, about 6.0 mg / kg, about 8.0 mg / kg, or about 10.0 mg / kg. In some embodiments, the antibody or antigen-binding fragment described herein is administered as an IV infusion every 14 days at a dose of about 0.1 mg / kg, about 0.5 mg / kg, about 1.0 mg / kg, about 2.0 mg / kg, about 3.0 mg / kg, about 4.0 mg / kg, about 5.0 mg / kg, about 6.0 mg / kg, about 8.0 mg / kg, or about 10.0 mg / kg. In some embodiments, the antibody or antigen-binding fragment described herein is administered as an IV infusion every 21 days at a dose of about 0.1 mg / kg, about 0.5 mg / kg, about 1.0 mg / kg, about 2.0 mg / kg, about 3.0 mg / kg, about 4.0 mg / kg, about 5.0 mg / kg, about 6.0 mg / kg, about 8.0 mg / kg, or about 10.0 mg / kg. In some embodiments, the antibody or antigen-binding fragment described herein is administered as an IV infusion every 28 days at a dose of about 0.1 mg / kg, about 0.5 mg / kg, about 1.0 mg / kg, about 2.0 mg / kg, about 3.0 mg / kg, about 4.0 mg / kg, about 5.0 mg / kg, about 6.0 mg / kg, about 8.0 mg / kg, or about 10.0 mg / kg.

[0170] When used in conjunction with or in combination with other agents (such as other chemotherapeutic agents), the antibodies or antigen-binding fragments described herein may be administered on the same schedule as or on a different schedule than the other agents. When administered on the same schedule, the antibodies or antigen-binding fragments described herein may be administered before, after, or concurrently with the other agent. In some embodiments, when the antibodies or antigen-binding fragments described herein are used in conjunction with or in combination with standard of care, the antibodies or antigen-binding fragments may be initiated before the start of standard of care, for example, one day, several days, one week, several weeks, one month, or even several months before the start of standard of care. In some embodiments, when the antibodies or antigen-binding fragments described herein are used in conjunction with or in combination with standard of care, the antibodies or antigen-binding fragments described herein may be initiated after the start of standard of care, for example, one day, several days, one week, several weeks, one month, or even several months after the start of standard of care.

[0171] Subcutaneous administration regimens can vary from once every six months to once daily, depending on a number of clinical factors, including the type and severity of the disease and the patient’s sensitivity to the antibodies or antigen-binding fragments described herein.

[0172] This disclosure also provides a method for treating posterior capsule opacification (PCO), the method comprising administering the antibody described herein or an antigen-binding fragment thereof to a patient in need of this treatment. In some embodiments, the antibody or antigen-binding fragment thereof is applied to the eye.

[0173] This disclosure also provides a method for treating fibrosis, the method comprising administering the antibody or antigen-binding fragment thereof described herein to a patient in need of treatment. In some embodiments, the antibody or antigen-binding fragment thereof is administered to an organ. In some embodiments, the organ is a kidney or a lung.

[0174] In some embodiments, the antibodies or antigen-binding fragments described herein can be used in methods for isolating and / or purifying cells (e.g., myofibroblast progenitor cells) by sorting the cells to which they bind. Such cells can rapidly migrate to wounds in the skin, lens, retina, and brain, thereby contributing to wound healing. These cells have the potential to develop into contractile myofibroblasts. Human adipose tissue is a source of such cells (i.e., BAI1). + One source of BAI1 cells (unpublished results). The isolated BAI1 cells... + Cells are applied to the human body or implanted into slow-healing or unhealed wounds, such as diabetic ulcers and pressure sores, as well as severe surgical incisions, to promote wound healing.

[0175] In some embodiments, the antibodies or antigen-binding fragments thereof described herein can be used in methods for isolating neuroprotective cells by sorting cells to which they bind. In response to retinal and brain injury, the number of cells expressing BAI1 increases. Such cells can be applied to the retina and brain to reduce neuronal death. Following injury, BAI1 can be expressed... + Cells and / or the molecules they produce are injected into the vitreous humor of the eye or the vascular system of the brain.

[0176] The following representative implementation schemes are provided:

[0177] Implementation Scheme 1. An antibody or antigen-binding fragment thereof that binds to human adhesion G protein-coupled receptor B1 (BAI1) protein, wherein the antibody or antigen-binding fragment thereof comprises: variable weight (V H The first complementarity-determining region (CDR) in the chain (V H -CDR1), which contains the amino acid sequence according to SEQ ID NO:7; the V H The second CDR (V) in the chainH -CDR2), which contains the amino acid sequence according to SEQ ID NO:8; the V H The third CDR (V) in the chain H -CDR3), which contains the amino acid sequence according to SEQ ID NO:9; variable light (V L The first CDR (V) in the chain L -CDR1), which contains the amino acid sequence according to SEQ ID NO:10; the V L The second CDR (V) in the chain L -CDR2), which comprises the amino acid sequence according to SEQ ID NO:11; and the V L The third CDR (V) in the chain L -CDR3), which contains the amino acid sequence according to SEQ ID NO:12.

[0178] Implementation Scheme 2. The antibody or antigen-binding fragment thereof according to Implementation Scheme 1, wherein the antibody or antigen-binding fragment thereof comprises V H Chain, the V H The chain contains the amino acid sequence according to SEQ ID NO:1.

[0179] Implementation Scheme 3. The antibody or antigen-binding fragment thereof according to Implementation Scheme 1, wherein the antibody or antigen-binding fragment thereof comprises V L Chain, the V L The chain contains the amino acid sequence according to SEQ ID NO:4.

[0180] Implementation Scheme 4. The antibody or antigen-binding fragment thereof according to Implementation Scheme 1, wherein the antibody or antigen-binding fragment thereof comprises V containing the amino acid sequence according to SEQ ID NO:1. H The chain and V containing the amino acid sequence according to SEQ ID NO:4 L chain.

[0181] Implementation Scheme 5. An antibody or antigen-binding fragment thereof according to any one of Implementation Schemes 1 to 4, wherein the antibody is an IgM or IgG antibody.

[0182] Implementation Scheme 6. An antibody or antigen-binding fragment thereof according to any one of Implementation Schemes 1 to 4, wherein the antibody is an IgM antibody.

[0183] Implementation Scheme 7. An antibody or antigen-binding fragment thereof according to any one of Implementation Schemes 1 to 4, wherein the antibody is an IgG antibody.

[0184] Implementation Scheme 8. The antibody or antigen-binding fragment thereof as described in Implementation Scheme 7, wherein the antibody is an IgG1 antibody.

[0185] Implementation Scheme 9. The antibody or its antigen-binding fragment according to Implementation Scheme 7, wherein the antibody is an IgG1G1m17 alloantibody.

[0186] Implementation Scheme 10. An antibody or antigen-binding fragment thereof according to any one of Implementation Schemes 1 to 9, wherein the antibody or antigen-binding fragment thereof is humanized.

[0187] Implementation Scheme 11. The humanized antibody or antigen-binding fragment thereof according to Implementation Scheme 10, wherein the humanized antibody or antigen-binding fragment thereof comprises a heavy chain, the heavy chain comprising the amino acid sequence according to SEQ ID NO:13.

[0188] Implementation Scheme 12. The humanized antibody or antigen-binding fragment thereof according to Implementation Scheme 10, wherein the humanized antibody or antigen-binding fragment thereof comprises a light chain comprising an amino acid sequence according to SEQ ID NO:14.

[0189] Implementation Scheme 13. The humanized antibody or antigen-binding fragment thereof according to Implementation Scheme 10, wherein the humanized antibody or antigen-binding fragment thereof comprises a heavy chain containing an amino acid sequence according to SEQ ID NO:13 and a light chain containing an amino acid sequence according to SEQ ID NO:14.

[0190] Implementation Scheme 14. An antibody or antigen-binding fragment thereof according to any one of Implementation Schemes 1 to 13, wherein the antibody or antigen-binding fragment thereof is conjugated to an effector moiety.

[0191] Implementation Scheme 15. An antibody or antigen-binding fragment thereof according to Implementation Scheme 14, wherein the effector portion is a detectable marker, cytotoxic agent, chemotherapeutic agent or nucleic acid molecule.

[0192] Implementation Scheme 16. The antibody or antigen-binding fragment thereof according to Implementation Scheme 15, wherein the detectable label is a radioactive compound, fluorescent compound, chromophore, enzyme, imaging agent, metal ion or substrate.

[0193] Implementation Scheme 17. The antibody or its antigen-binding fragment according to Implementation Scheme 15, wherein the cytotoxic agent is a small molecule, a prodrug, maytansine alkaloid, or a toxin.

[0194] Implementation Scheme 18. An antibody or antigen-binding fragment thereof according to Implementation Scheme 15, wherein each antibody or antigen-binding fragment thereof contains 3 to 5 maytansine alkaloid molecules.

[0195] Implementation Scheme 19. The antibody or antigen-binding fragment thereof according to Implementation Scheme 18, wherein the maytansine alkaloid is conjugated to the antibody or antigen-binding fragment thereof via a chemical linker selected from N-succinimide-3-(2-pyridyldithio)propionate, N-succinimide-4-(2-pyridylthio)valerate (SPP) and succinimide-4-(N-maleimidemethyl)cyclohexane-1-carboxylate.

[0196] Implementation Scheme 20. The antibody or its antigen-binding fragment according to Implementation Scheme 15, wherein the cytotoxic agent is paclitaxel, cytochalasin B, bacitracin D, ethidium bromide, emetine, mitomycin, etoposide, teniposide, vincristine, vinblastine, colchicine, doxorubicin, daunorubicin, dihydroxyanthraquinone, mitoxantrone, glaucomacin, actinomycin D, 1-dehydrotestosterone, glucocorticoids, procaine, tetracaine, lidocaine, propranolol, or puromycin.

[0197] Implementation Scheme 21. The antibody or its antigen-binding fragment according to Implementation Scheme 15, wherein the chemotherapeutic agent is cisplatin, carboplatin, oxaliplatin, nedaplatin, triplatinum tetranitrate, phenanthreneplatin, pyridine, ceterplatin, methotrexate, vincristine, doxorubicin, tunicamycin, oligomycin, bortezomib, MG132, 5-fluorouracil, sorafenib, flapindole, gemcitabine, paclitaxel, mercaptopurine, thioguanine, hydroxyurea, cytarabine, mitomycin, cyclophosphamide, ifosfamide, nitrosourea, dacarbazine. Procaine, etoposide, camptothecin, bleomycin, idarubicin, daunorubicin, actinomycin D, phenobarbital A, etidine, fusiformin, auristatin, acridine, styracin, bortezomib, pipfenzidol, thromycin, pyroxine SA, procaine, mitoxantrone, asparaginase, vinblastine, vinorelbine, paclitaxel, docetaxel, CPT-11, glimepiride, erlotinib, gefitinib, ibrutinib, crizotinib, ceritinib, lapatinib, navittox, or regorafenib.

[0198] Implementation Scheme 22. The antibody or its antigen-binding fragment according to Implementation Scheme 15, wherein the nucleic acid molecule is a monolayer nucleic acid carrier, a 1.5-layer nucleic acid carrier, a bilayer nucleic acid carrier, a 2.5-layer nucleic acid carrier, or a trilayer nucleic acid carrier.

[0199] Implementation Scheme 23. An antibody or an antigen-binding fragment thereof according to any one of Implementation Schemes 1 to 22, wherein the antigen-binding fragment is Fab, F(ab')2, Fv, scFv, scFv-Fc, a double-chain antibody or a microantibody fragment.

[0200] Implementation Scheme 24. A pharmaceutical composition comprising an antibody or an antigen-binding fragment thereof as described in any one of claims 1 to 23, and a pharmaceutically acceptable carrier.

[0201] Implementation Scheme 25. The pharmaceutical composition according to Implementation Scheme 24, wherein the pharmaceutical composition is a liquid pharmaceutical composition.

[0202] Implementation Scheme 26. The pharmaceutical composition according to Implementation Scheme 24 or Implementation Scheme 25 further comprises a tension agent, a surfactant, a preservative and / or a buffer system with a pH of about 4.0 to about 8.0.

[0203] Implementation Scheme 27. An isolated nucleic acid molecule encoding a V-type antibody or antigen-binding fragment thereof according to any one of Implementation Schemes 1 to 9. H The chain, wherein the nucleic acid molecule comprises a nucleotide sequence according to SEQ ID NO:2 or SEQ ID NO:3.

[0204] Implementation Scheme 28. An isolated nucleic acid molecule encoding a V-type antibody or antigen-binding fragment thereof according to any one of Implementation Schemes 1 to 9. L The chain, wherein the nucleic acid molecule comprises a nucleotide sequence according to SEQ ID NO:5 or SEQ ID NO:6.

[0205] Implementation Scheme 29. A carrier comprising a nucleic acid molecule as described in Implementation Scheme 27 or Implementation Scheme 28.

[0206] Implementation Scheme 30. A prokaryotic host cell transformed with the vector according to Implementation Scheme 29.

[0207] Implementation Scheme 31. A eukaryotic host cell transformed with the vector according to Implementation Scheme 29.

[0208] Implementation Scheme 32. The eukaryotic host cell described in Implementation Scheme 31 is a mammalian host cell.

[0209] Implementation Scheme 33. A method for detecting cells expressing BAI1, the method comprising contacting the cells with an antibody or an antigen-binding fragment thereof according to any one of Implementation Schemes 1 to 23, and detecting the antibody or the antigen-binding fragment thereof.

[0210] Implementation Scheme 34. The method according to Implementation Scheme 33, wherein the cells are present in a biological sample obtained from a human, and the cells are contacted in vitro with an antibody or an antigen-binding fragment thereof.

[0211] Implementation Scheme 35. The method according to Implementation Scheme 33, wherein the cell is present in a human body and the cell is in contact with an antibody or an antigen-binding fragment thereof in vivo.

[0212] Implementation Scheme 36. A method for treating cancer expressing BAI1, the method comprising administering to a patient in need an antibody or an antigen-binding fragment thereof according to any one of Implementation Schemes 1 to 23.

[0213] Implementation Scheme 37. The method according to Implementation Scheme 36, wherein the cancer expressing BAI1 is a nervous system cancer.

[0214] Implementation Scheme 38. The method according to Implementation Scheme 37, wherein the nervous system cancer is a primary brain tumor, glioblastoma, glioma, meningioma, schwannoma, pituitary adenoma, medulloblastoma, craniopharyngioma, hemangioma, epidermoid tumor, sarcoma, or intracranial metastasis from other tumor sources.

[0215] Implementation Scheme 39. The method according to Implementation Scheme 38, wherein the nervous system cancer is glioblastoma.

[0216] Implementation Scheme 40. The method according to any one of Implementation Schemes 36 to 39, wherein the antibody or its antigen-binding fragment is administered intravenously or intracranially.

[0217] Implementation Scheme 41. The method according to any one of Implementation Schemes 36 to 40, further comprising administering at least one chemotherapeutic agent to the patient.

[0218] Implementation Scheme 42. The method according to any one of Implementation Schemes 36 to 41 further includes surgical resection of tumor cells and / or administration of radiotherapy, or both.

[0219] Implementation Scheme 43. A method for treating posterior capsule opacification (PCO), the method comprising administering to a patient in need an antibody or an antigen-binding fragment thereof according to any one of Implementation Schemes 1 to 23.

[0220] Implementation Scheme 44. The method according to Implementation Scheme 43, wherein the antibody or its antigen-binding fragment is applied to the eye.

[0221] Implementation Scheme 45. A method for treating fibrosis, the method comprising administering to a patient in need an antibody or an antigen-binding fragment thereof according to any one of Implementation Schemes 1 to 23.

[0222] Implementation Scheme 46. The method according to Implementation Scheme 45, wherein the antibody or its antigen-binding fragment is applied to an organ.

[0223] Implementation Scheme 47. The method according to Implementation Scheme 46, wherein the organ is a kidney or a lung.

[0224] Implementation Scheme 48. A method for promoting wound healing, the method comprising administering to a patient in need an antibody or an antigen-binding fragment thereof according to any one of Implementation Schemes 1 to 23.

[0225] Implementation Scheme 49. The method according to Implementation Scheme 48, wherein the wound is present in the skin, lens, retina or brain.

[0226] Implementation Scheme 50. The method according to Implementation Scheme 48, wherein the wound is a diabetic ulcer or a pressure ulcer.

[0227] Implementation Scheme 51. A method for promoting wound healing, the method comprising administering cells expressing BAI1 to a patient in need of such treatment.

[0228] To better understand the subject matter disclosed herein, examples are provided below. It should be understood that these examples are for illustrative purposes only and should not be construed as limiting the claimed subject matter in any way. In all these examples, unless otherwise stated, molecular cloning reactions and other standard recombinant DNA techniques were performed using commercially available reagents according to the methods described in Maniatis et al., Molecular Cloning—A Laboratory Manual, 2nd edition, Cold Spring Harbor Press (1989). As used herein, unless otherwise stated, the numbering of immunoglobulin amino acid residues is based on the immunoglobulin amino acid residue numbering system of Kabat et al.

[0229] Example

[0230] Example 1: Identification of G8 (BAI1) antigen

[0231] Membrane proteome arrays (MPAs) are platforms for analyzing the specificity of antibodies and other ligands targeting human membrane proteins. MPAs can be used to determine antibody target specificity, deconvolve orphan antibody targets, and characterize the target profile of biosimilar candidates. Flow cytometry is used to directly detect antibodies that bind to membrane proteins expressed in eukaryotic cells, such as human HEK-293 cells. Therefore, all MPA targets are designed with native conformations and appropriate post-translational modifications. The workflow of this process is as follows: Figure 1 As shown. The reactivity of the G8 antibody to an MPA library of over 4,500 human membrane proteins (including GPCRs, ion channels, and transporters) was tested. Identified targets were validated in a secondary screening to confirm reactivity.

[0232] To determine the optimal antibody concentration and minimize background reactivity, HEK-293T (human) cells expressing either protein A or protein G constructs or vectors were examined at different concentrations of G8 batch 3 / 21 / 13 and G8 batch PS30170160. These experiments were performed in 384-well format using a single dilution of the secondary antibody. Figure 2A and Figure 2B (Table 1). Data from the assay setup experiments were used to determine the optimal screening conditions for the high-throughput immunoassay (Table 2). In short, to optimize antibody detection conditions, cells were transfected in 384-well format with separate protein A and G expression constructs (positive controls for MAb binding) or vectors (negative controls), followed by detection of cell expression using high-throughput immunofluorescence flow cytometry. The immunoreactivity of each assay and control MAb serial dilution (starting from 4 μg / ml) against cells expressing separate proteins A and G or vectors was examined. IgM was found not to react strongly with the positive control construct. Therefore, these experiments were used to determine conditions exhibiting low background reactivity. Low background reactivity indicates that detection at high concentrations is possible and does not mask potential hits.

[0233] Table 1: Filtering Criteria

[0234]

[0235] Table 2: Experimental parameters for high-throughput immunoassay

[0236]

[0237]

[0238] Determination of antibody binding targets

[0239] To identify antibody binding targets, 5,300 different membrane proteins were expressed in HEK-293T cells arranged in individual wells of a 384-well plate. The cells were then matrixed by aggregating the columns and rows of each 384-well plate. The resulting MPA matrix was probed with G8 batch 3 / 21 / 13 and G8 batch PS30170160 at a concentration of 30 μg / ml, followed by detection with fluorescently labeled secondary antibodies. Fluorescence readings for each plate were validated using positive (constructs expressing known targets) and negative (empty vector) controls. Each individual membrane protein target was assigned a binding value corresponding to its unique set of rows and columns. The resulting binding values ​​(including row and column components) were normalized and transformed to give a single numerical value for antibody binding to each target protein (normalized target binding). Targets were then identified by detecting the binding of antibodies to overlapping sets of columns and rows from the same plate, allowing for specific deconvolution. Figure 3A and Figure 3B(Table 3). Antibody binding was detected by flow cytometry using fluorescent secondary antibodies.

[0240] Table 3: G8 batch: 3 / 21 / 13 and batch: PS30170160 membrane protein targets

[0241] Antibody Target gene (HGNC) Uniprot G8 batch 3 / 21 / 13 BAI1 E5RG74 G8 batch PS30170160 BAI1 E5RG74

[0242] This screening yielded binding targets, which were confirmed in a secondary flow cytometry assay using serial antibody dilutions. Figure 4A and Figure 4B To this end, HEK-293T cells were transfected with plasmid constructs expressing individual targets or vectors. The immunoreactivity of serial dilutions of each MAb on cells expressing individual target proteins or vectors was tested. Finally, the identities of all targets were re-verified by sequencing.

[0243] Example 2: RACE identification of G8 heavy and light chains

[0244] To identify the heavy and light chain nucleic acid molecules encoding the G8 antibody, a rapid cDNA end amplification (RACE) reaction was performed. The RACE PCR sample was analyzed on an agarose gel to make the amplified DNA fragments visible. The correct antibody variable region DNA fragments, with a size between 500-700 base pairs, were amplified. Figure 5 ).

[0245] DNA fragments amplified by PCR from 24 clones were recovered from agarose gels and sequenced. CDRs were identified using the VBASE2 tool.

[0246] Example 3: Construction, generation and characterization of humanized anti-BAI1 IgG

[0247] G8 IgG expression constructs were cloned into a high-expression mammalian vector. Each G8 IgG DNA construct was amplified for transfection and its sequence was confirmed. A transient production of 0.03 L was achieved in HEK293 cells (Tuna293). TM (Process). Conditioned culture medium from the transient production run is harvested and clarified by centrifugation and filtration. The supernatant is loaded onto a protein A column pre-equilibrated with binding buffer. Wash buffer is passed through the column until the OD is measured. 280 The NanoDrop (ThermoScientific) value is zero. The target protein is eluted with a low pH buffer, fractions are collected, and the OD value of each fraction is recorded. 280 Value. Fractions containing the target protein were combined and filtered through a 0.2 μm filter. (Oddi concentration) 280Protein concentration was calculated using the extinction coefficient and the calculated value, yielding 2.92 mg of G8 IgG. Data are summarized in Table 4 under Final Protein Yield, Aliquots, and Analysis.

[0248] Table 4

[0249]

[0250] Table 4 (continued)

[0251]

[0252] Subsequently, CE-SDS analysis was performed using LabChip GXII (Perkin Elmer). Endotoxin levels in purified samples were measured using the chromogenic horseshoe crab cell lysate assay (Endosafe-MCS, Charles River). Samples were run in duplicate. Experiments confirmed that all samples met the requirement of <1 EU / mg (Table 4). SE-UPLC analysis was performed, with the SEC standard (MEDNA, catalog number Y3101) used as a reference run for protein size. All proteins were observed to contain >99% monomers. Complete quality QC was performed by mass spectrometry, and the observed IgG molecular weights were within the expected range.

[0253] To measure the relative affinity of G8 IgM and anti-BAI1 IgG (referred to herein as "G8 IgG"), ELISA assays were performed on G8 IgG and G8 IgM. Briefly, plates were coated overnight at 4°C with 2 μg / ml human BAI1 and blocked for 1 hour at room temperature with 1% BSA in PBS. Initial incubation was performed for 1 hour at room temperature with either sequential 1:2 dilutions of G8 IgM (starting from 20 μg / ml) or sequential 1:2 dilutions of G8 IgG (anti-BAI1 IgG) (starting from 100 μg / ml). Secondary incubation was performed for 1 hour at room temperature with either HRP-conjugated anti-mouse IgM Fc (G8 IgM) or HRP-conjugated anti-human Fc (G8 IgG). Assays were performed by incubation with 3,3',5,5'-tetramethylbenzidine (TMB) for 15 minutes and terminated with 1M HCl. All assays were performed in duplicate. Results are shown in… Figure 6 In the ELISA test, both G8 IgG and G8 IgM control samples showed positive signals.

[0254] Based on the foregoing description, various modifications to the described subject matter, other than those described herein, will be apparent to those skilled in the art. Such modifications are also intended to fall within the scope of the appended claims. Each reference cited in this application (including, but not limited to, journal articles, U.S. and non-U.S. patents, patent application publications, international patent application publications, gene bank accession numbers, etc.) is incorporated herein by reference in its entirety. sequence list <110> Genisphere, LLC Robert R. Gates J. Bowers (Jessica) M.E. George Weinstein (Mindy Ellen) J. Gerhart (Jacquelyn) <120> Brain-specific angiogenesis inhibitor 1 (BAI1) antibody and its uses <130> 189099.00502 (3035) <150> 62 / 929,986 <151> 2019-11-04 <160> 15 <170> PatentIn version 3.5 <210> 1 <211> 118 <212> PRT <213> Homo sapiens <400> 1 Ser Asp Val Gln Leu Gln Glu Ser Gly Pro Gly Leu Val Lys Pro Ser 1 5 10 15 Gln Ser Leu Ser Leu Thr Cys Thr Val Thr Gly Tyr Ser Ile Thr Ser 20 25 30 Asp Tyr Ala Trp Asn Trp Ile Arg Gln Phe Pro Gly Asn Lys Leu Glu 35 40 45 Trp Met Gly Tyr Ile Ser Tyr Ser Gly Ser Thr Ser Tyr Asn Pro Ser 50 55 60 Leu Lys Ser Arg Ile Ser Ile Thr Arg Asp Thr Lys Ser Asn Gln Phe 65 70 75 80 Phe Leu Gln Leu Asn Ser Val Thr Glu Asp Thr Ala Thr Tyr Tyr 85 90 95 Cys Only Asn Only Gln Gly Tyr Only Met Asp Tyr Trp Gly Gln Gly Thr 100 105 110 Will Be Thr Will Be 115 <210> 2 <211> 354 <212> DNA <213> Homo sapien <400> 2 tctgatgtgc agcttcagga gtcgggacct ggctggtga aaccttca gtctctgtcc 60 ctcacctgca ctgtcactgg ctactcaatc accagtgat atgcctggaa ctggatccgg 120 cagtttccag gaacaact ggagtgtg gctacataa gctacagtgg tagcactagc 180 tacaacccat ctctcaaag tcgaatctct atcactcgag accacatccaa gaaccagttc 240 ttcctgcagt tgaattctgt gactactgag gatacagcca catattactg tgccaatgcc 300 caggggtag ctatggacta ctggggtca ggaacctcag tcaccgtc ctca 354 <210> 3 <211> 354 <212> RNA <213> Homo sapien <400> 3 ucugaugugc agcuucagga gucgggaccu ggccugguga accucuca gucucugucc 60 cucaccugca cugucacugg cucucauc accagugauu augccuggaa cuggauccgg 120 caguuuccag gaacaacu ggaguggaug ggcuacauaa gcuacagugg uagcacuagc 180 hurricane cucucaaag ucgaaucucu aucacucgag hurricane gaaccaguuc 240 uuccugcagu ugaauucugu gacuacugag garcagcca cauauuacug ugccaaugcc 300 caggguaug cuauggacua cugggucha ggaaccucag ucaccgucuc cuca 354 <210> 4 <211> 107 <212> PRT <213> Homo sapien <400> 4 Asp Ile Val Met Thr Gln Ser Pro Ala Thr Leu Ser Val Thr Pro Gly 1 5 10 15 Asp Arg Will Be Leu Be Cys Arg Ala Be Gln Be Ile Be Asp Tyr 20 25 30 Leu His Trp Tyr Gln Gln Lys Ser His Glu Ser Pro Arg Leu Ile 35 40 45 Lys Tyr Ala Ser Gln Ser Ile Ser Gly Ile Pro Ser Arg Phe Ser Gly 50 55 60 Ser Gly Ser Gly Ser Asp Phe Thr Leu Ser Ile Asn Ser Val Glu Pro 65 70 75 80 Glu Asp Val Gly Val Tyr Tyr Cys Gln Asn Gly His Ser Phe Pro Phe 85 90 95 Thr Phe Gly Ser Gly Thr Lys Leu Glu Ile Lys 100 105 <210> 5 <211> 321 <212> DNA <213> Homo sapien <400> 5 gatattgtga tgactcagtc tccagccacc ctgtctgtga ctccaggaga tagatctct 60 ctttcctgca gggccagcca gagtattagc gactactac actggtatca acaaaaatca 120 catgagtctc caagcttct catcaatat gctcccaat catctctgg gatcccctcc 180 aggttcagtg gcagtgatc agggtcagat ttcactca gtatcacag tgtgaacct 240 gaagatgttg gagtgtatta ctgtcaaat ggtcacagct ttccattcac gttcggctcg 300 gggacaaagt tggaaataaa a 321 <210> 6 <211> 321 <212> RNA <213> Homo sapiens <400> 6 gacauuguga ugacucaguc uccagccacc cugucuguga cuccaggaga uagagucucu 60 cuuuccugca gggccagcca gaguauuagc gacuacuuac acugguauca acaaaaauca 120 caugagucuc caaggcuucu caucaaauau gcuucccaau ccaucucugg gauccccucc 180 agguucagug gcaguggauc agggucagau uucacucuca guaucaacag uguggaaccu 240 gaagauguug gaguguauua cugucaaaau ggucacagcu uuccauucac guucggcucg 300 gggacaaagu uggaaauaaa a 321 <210> 7 <211> 8 <212> PRT <213> Homo sapiens <400> 7 Gly Tyr Ser Ile Thr Ser Asp Tyr 1 5 <210> 8 <211> 5 <212> PRT <213> Homo sapiens <400> 8 Ser Tyr Ser Gly Ser 1 5 <210> 9 <211> 8 <212> PRT <213> Homo sapien <400> 9 Ala Gln Gly Tyr Ala Met Asp Tyr 1 5 <210> 10 <211> 11 <212> PRT <213> Homo sapien <400> 10 Arg Ala Ser Gln Ser Ile Ser Asp Tyr Leu His 1 5 10 <210> 11 <211> 7 <212> PRT <213> Homo sapien <400> 11 Tyr Ala Ser Gln Ser Ile Ser 1 5 <210> 12 <211> 9 <212> PRT <213> Homo sapien <400> 12 Gln Asn Gly His Ser Phe Pro Phe Thr 1 5 <210> 13 <211> 445 <212> PRT <213> Homo sapien <400> 13 Val Gln Leu Gln Glu Ser Gly Pro Gly Leu Val Lys Pro Ser Gln Ser 1 5 10 15 Leu Ser Leu Thr Cys Thr Val Thr Gly Tyr Ser Ile Thr Ser Asp Tyr 20 25 30 Ala Trp Asn Trp Ile Arg Gln Phe Pro Gly Asn Lys Leu Glu Trp Met 35 40 45 Gly Tyr Ile Ser Tyr Ser Gly Ser Thr Ser Tyr Asn Pro Ser Leu Lys 50 55 60 Ser Arg Ile Ser Ile Thr Arg Asp Thr Ser Lys Asn Gln Phe Phe Leu 65 70 75 80 Gln Leu Asn Ser Val Thr Thr Glu Asp Thr Ala Thr Tyr Tyr Cys Ala 85 90 95 Asn Ala Gln Gly Tyr Ala Met Asp Tyr Trp Gly Gln Gly Thr Ser Val 100 105 110 Thr Val Ser Ser Ala Ser Thr Lys Gly Pro Ser Val Phe Pro Leu Ala 115 120 125 Pro Ser Ser Lys Ser Thr Ser Gly Gly Thr Ala Ala Leu Gly Cys Leu 130 135 140 Val Lys Asp Tyr Phe Pro Glu Pro Val Thr Val Ser Trp Asn Ser Gly 145 150 155 160 Ala Leu Thr Ser Gly Val His Thr Phe Pro Ala Val Leu Gln Ser Ser 165 170 175 Gly Leu Tyr Ser Leu Ser Ser Val Val Thr Val Pro Ser Ser Ser Leu 180 185 190 Gly Thr Gln Thr Tyr Ile Cys Asn Val Asn His Lys Pro Ser Asn Thr 195 200 205 Lys Val Asp Lys Lys Val Glu Pro Lys Ser Cys Asp Lys Thr His Thr 210 215 220 Cys Pro Pro Cys Pro Ala Pro Glu Leu Leu Gly Gly Pro Ser Val Phe 225 230 235 240 Leu Phe Pro Pro Lys Pro Lys Asp Thr Leu Met Ile Ser Arg Thr Pro 245 250 255 Glu Val Thr Cys Val Val Val Asp Val Ser His Glu Asp Pro Glu Val 260 265 270 Lys Phe Asn Trp Tyr Val Asp Gly Val Glu Val His Asn Ala Lys Thr 275 280 285 Lys Pro Arg Glu Glu Gln Tyr Asn Ser Thr Tyr Arg Val Val Ser Val 290 295 300 Leu Thr Val Leu His Gln Asp Trp Leu Asn Gly Lys Glu Tyr Lys Cys 305 310 315 320 Lys Val Ser Asn Lys Ala Leu Pro Ala Pro Ile Glu Lys Thr Ile Ser 325 330 335 Lys Ala Lys Gly Gln Pro Arg Glu Pro Gln Val Tyr Thr Leu Pro Pro 340 345 350 Ser Arg Glu Glu Met Thr Lys Asn Gln Val Ser Leu Thr Cys Leu Val 355 360 365 Lys Gly Phe Tyr Pro Ser Asp Ile Ala Val Glu Trp Glu Ser Asn Gly 370 375 380 Gln Pro Glu Asn Asn Tyr Lys Thr Thr Pro Pro Val Leu Asp Ser Asp 385 390 395 400 Gly Ser Phe Phe Leu Tyr Ser Lys Leu Thr Val Asp Lys Ser Arg Trp 405 410 415 Gln Gln Gly Asn Val Phe Ser Cys Ser Val Met His Glu Ala Leu His 420 425 430 Asn His Tyr Thr Gln Lys Ser Leu Ser Leu Ser Pro Gly 435 440 445 <210> 14 <211> 214 <212> PRT <213> Homo sapiens <400> 14 Asp Ile Val Met Thr Gln Ser Pro Ala Thr Leu Ser Val Thr Pro Gly 1 5 10 15 Asp Arg Val Ser Leu Ser Cys Arg Ala Ser Gln Ser Ile Ser Asp Tyr 20 25 30 Leu His Trp Tyr Gln Gln Lys Ser His Glu Ser Pro Arg Leu Leu Ile 35 40 45 Lys Tyr Ala Ser Gln Ser Ile Ser Gly Ile Pro Ser Arg Phe Ser Gly 50 55 60 Ser Gly Ser Gly Ser Asp Phe Thr Leu Ser Ile Asn Ser Val Glu Pro 65 70 75 80 Glu Asp Val Gly Val Tyr Tyr Cys Gln Asn Gly His Ser Phe Pro Phe 85 90 95 Thr Phe Gly Ser Gly Thr Lys Leu Glu Ile Lys Arg Thr Val Ala Ala 100 105 110 Pro Ser Val Phe Ile Phe Pro Pro Ser Asp Glu Gln Leu Lys Ser Gly 115 120 125 Thr Ala Ser Val Val Cys Leu Leu Asn Asn Phe Tyr Pro Arg Glu Ala 130 135 140 Lys Val Gln Trp Lys Val Asp Asn Ala Leu Gln Ser Gly Asn Ser Gln 145 150 155 160 Glu Ser Val Thr Glu Gln Asp Ser Lys Asp Ser Thr Tyr Ser Leu Ser 165 170 175 Ser Thr Leu Thr Leu Ser Lys Ala Asp Tyr Glu Lys His Lys Val Tyr 180 185 190 Ala Cys Glu Val Thr His Gln Gly Leu Ser Ser Pro Val Thr Lys Ser 195 200 205 Phe Asn Arg Gly Glu Cys 210 <210> 15 <211> 1584 <212> PRT <213> Homo sapiens <400> 15 Met Arg Gly Gln Ala Ala Ala Pro Gly Pro Val Trp Ile Leu Ala Pro 1 5 10 15 Leu Leu Leu Leu Leu Leu Leu Leu Gly Arg Arg Ala Arg Ala Ala Ala 20 25 30 Gly Ala Asp Ala Gly Pro Gly Pro Glu Pro Cys Ala Thr Leu Val Gln 35 40 45 Gly Lys Phe Phe Gly Tyr Phe Ser Ala Ala Ala Val Phe Pro Ala Asn 50 55 60 Ala Ser Arg Cys Ser Trp Thr Leu Arg Asn Pro Asp Pro Arg Arg Tyr 65 70 75 80 Thr Leu Tyr Met Lys Val Ala Lys Ala Pro Val Pro Cys Ser Gly Pro 85 90 95 Gly Arg Val Arg Thr Tyr Gln Phe Asp Ser Phe Leu Glu Ser Thr Arg 100 105 110 Thr Tyr Leu Gly Val Glu Ser Phe Asp Glu Val Leu Arg Leu Cys Asp 115 120 125 Pro Ser Ala Pro Leu Ala Phe Leu Gln Ala Ser Lys Gln Phe Leu Gln 130 135 140 Met Arg Arg Gln Gln Pro Pro Gln His Asp Gly Leu Arg Pro Arg Ala 145 150 155 160 Gly Pro Pro Gly Pro Thr Asp Asp Phe Ser Val Glu Tyr Leu Val Val 165 170 175 Gly Asn Arg Asn Pro Ser Arg Ala Ala Cys Gln Met Leu Cys Arg Trp 180 185 190 Leu Asp Ala Cys Leu Ala Gly Ser Arg Ser Ser His Pro Cys Gly Ile 195 200 205 Met Gln Thr Pro Cys Ala Cys Leu Gly Gly Glu Ala Gly Gly Pro Ala 210 215 220 Ala Gly Pro Leu Ala Pro Arg Gly Asp Val Cys Leu Arg Asp Ala Val 225 230 235 240 Ala Gly Gly Pro Glu Asn Cys Leu Thr Ser Leu Thr Gln Asp Arg Gly 245 250 255 Gly His Gly Ala Thr Gly Gly Trp Lys Leu Trp Ser Leu Trp Gly Glu 260 265 270 Cys Thr Arg Asp Cys Gly Gly Gly Leu Gln Thr Arg Thr Arg Thr Cys 275 280 285 Leu Pro Ala Pro Gly Val Glu Gly Gly Gly Cys Glu Gly Val Leu Glu 290 295 300 Glu Gly Arg Gln Cys Asn Arg Glu Ala Cys Gly Pro Ala Gly Arg Thr 305 310 315 320 Ser Ser Arg Ser Gln Ser Leu Arg Ser Thr Asp Ala Arg Arg Arg Glu 325 330 335 Glu Leu Gly Asp Glu Leu Gln Gln Phe Gly Phe Pro Ala Pro Gln Thr 340 345 350 Gly Asp Pro Ala Ala Glu Glu Trp Ser Pro Trp Ser Val Cys Ser Ser 355 360 365 Thr Cys Gly Glu Gly Trp Gln Thr Arg Thr Arg Phe Cys Val Ser Ser 370 375 380 Ser Tyr Ser Thr Gln Cys Ser Gly Pro Leu Arg Glu Gln Arg Leu Cys 385 390 395 400 Asn Asn Ser Ala Val Cys Pro Val His Gly Ala Trp Asp Glu Trp Ser 405 410 415 Pro Trp Ser Leu Cys Ser Ser Thr Cys Gly Arg Gly Phe Arg Asp Arg 420 425 430 Thr Arg Thr Cys Arg Pro Pro Gln Phe Gly Gly Asn Pro Cys Glu Gly 435 440 445 Pro Glu Lys Gln Thr Lys Phe Cys Asn Ile Ala Leu Cys Pro Gly Arg 450 455 460 Ala Val Asp Gly Asn Trp Asn Glu Trp Ser Ser Trp Ser Ala Cys Ser 465 470 475 480 Ala Ser Cys Ser Gln Gly Arg Gln Gln Arg Thr Arg Glu Cys Asn Gly 485 490 495 Pro Ser Tyr Gly Gly Ala Glu Cys Gln Gly His Trp Val Glu Thr Arg 500 505 510 Asp Cys Phe Leu Gln Gln Cys Pro Val Asp Gly Lys Trp Gln Ala Trp 515 520 525 Ala Ser Trp Gly Ser Cys Ser Val Thr Cys Gly Ala Gly Ser Gln Arg 530 535 540 Arg Glu Arg Val Cys Ser Gly Pro Phe Phe Gly Gly Ala Ala Cys Gln 545 550 555 560 Gly Pro Gln Asp Glu Tyr Arg Gln Cys Gly Thr Gln Arg Cys Pro Glu 565 570 575 Pro His Glu Ile Cys Asp Glu Asp Asn Phe Gly Ala Val Ile Trp Lys 580 585 590 Glu Thr Pro Ala Gly Glu Val Ala Ala Val Arg Cys Pro Arg Asn Ala 595 600 605 Thr Gly Leu Ile Leu Arg Arg Cys Glu Leu Asp Glu Glu Gly Ile Ala 610 615 620 Tyr Trp Glu Pro Pro Thr Tyr Ile Arg Cys Val Ser Ile Asp Tyr Arg 625 630 635 640 Asn Ile Gln Met Met Thr Arg Glu His Leu Ala Lys Ala Gln Arg Gly 645 650 655 Leu Pro Gly Glu Gly Val Ser Glu Val Ile Gln Thr Leu Val Glu Ile 660 665 670 Ser Gln Asp Gly Thr Ser Tyr Ser Gly Asp Leu Leu Ser Thr Ile Asp 675 680 685 Val Leu Arg Asn Met Thr Glu Ile Phe Arg Arg Ala Tyr Tyr Ser Pro 690 695 700 Thr Pro Gly Asp Val Gln Asn Phe Val Gln Ile Leu Ser Asn Leu Leu 705 710 715 720 Ala Glu Glu Asn Arg Asp Lys Trp Glu Glu Ala Gln Leu Ala Gly Pro 725 730 735 Asn Ala Lys Glu Leu Phe Arg Leu Val Glu Asp Phe Val Asp Val Ile 740 745 750 Gly Phe Arg Met Lys Asp Leu Arg Asp Ala Tyr Gln Val Thr Asp Asn 755 760 765 Leu Val Leu Ser Ile His Lys Leu Pro Ala Ser Gly Ala Thr Asp Ile 770 775 780 Ser Phe Pro Met Lys Gly Trp Arg Ala Thr Gly Asp Trp Ala Lys Val 785 790 795 800 Pro Glu Asp Arg Val Thr Val Ser Lys Ser Val Phe Ser Thr Gly Leu 805 810 815 Thr Glu Ala Asp Glu Ala Ser Val Phe Val Val Gly Thr Val Leu Tyr 820 825 830 Arg Asn Leu Gly Ser Phe Leu Ala Leu Gln Arg Asn Thr Thr Val Leu 835 840 845 Asn Ser Lys Val Ile Ser Val Thr Val Lys Pro Pro Pro Arg Ser Leu 850 855 860 Arg Thr Pro Leu Glu Ile Glu Phe Ala His Met Tyr Asn Gly Thr Thr 865 870 875 880 Asn Gln Thr Cys Ile Leu Trp Asp Glu Thr Asp Val Pro Ser Ser Ser 885 890 895 Ala Pro Pro Gln Leu Gly Pro Trp Ser Trp Arg Gly Cys Arg Thr Val 900 905 910 Pro Leu Asp Ala Leu Arg Thr Arg Cys Leu Cys Asp Arg Leu Ser Thr 915 920 925 Phe Ala Ile Leu Ala Gln Leu Ser Ala Asp Ala Asn Met Glu Lys Ala 930 935 940 Thr Leu Pro Ser Val Thr Leu Ile Val Gly Cys Gly Val Ser Ser Leu 945 950 955 960 Thr Leu Leu Met Leu Val Ile Ile Tyr Val Ser Val Trp Arg Tyr Ile 965 970 975 Arg Ser Glu Arg Ser Val Ile Leu Ile Asn Phe Cys Leu Ser Ile Ile 980 985 990 Ser Ser Asn Ala Leu Ile Leu Ile Gly Gln Thr Gln Thr Arg Asn Lys 995 1000 1005 Val Val Cys Thr Leu Val Ala Ala Phe Leu His Phe Phe Phe Leu 1010 1015 1020 Ser Ser Phe Cys Trp Val Leu Thr Glu Ala Trp Gln Ser Tyr Met 1025 1030 1035 Ala Val Thr Gly His Leu Arg Asn Arg Leu Ile Arg Lys Arg Phe 1040 1045 1050 Leu Cys Leu Gly Trp Gly Leu Pro Ala Leu Val Val Ala Ile Ser 1055 1060 1065 Val Gly Phe Thr Lys Ala Lys Gly Tyr Ser Thr Met Asn Tyr Cys 1070 1075 1080 Trp Leu Ser Leu Glu Gly Gly Leu Leu Tyr Ala Phe Val Gly Pro 1085 1090 1095 Ala Ala Ala Val Val Leu Val Asn Met Val Ile Gly Ile Leu Val 1100 1105 1110 Phe Asn Lys Leu Val Ser Lys Asp Gly Ile Thr Asp Lys Lys Leu 1115 1120 1125 Lys Glu Arg Ala Gly Ala Ser Leu Trp Ser Ser Cys Val Val Leu 1130 1135 1140 Pro Leu Leu Ala Leu Thr Trp Met Ser Ala Val Leu Ala Val Thr 1145 1150 1155 Asp Arg Arg Ser Ala Leu Phe Gln Ile Leu Phe Ala Val Phe Asp 1160 1165 1170 Ser Leu Glu Gly Phe Val Ile Val Met Val His Cys Ile Leu Arg 1175 1180 1185 Arg Glu Val Gln Asp Ala Val Lys Cys Arg Val Val Asp Arg Gln 1190 1195 1200 Glu Glu Gly Asn Gly Asp Ser Gly Gly Ser Phe Gln Asn Gly His 1205 1210 1215 Ala Gln Leu Met Thr Asp Phe Glu Lys Asp Val Asp Leu Ala Cys 1220 1225 1230 Arg Ser Val Leu Asn Lys Asp Ile Ala Ala Cys Arg Thr Ala Thr 1235 1240 1245 Ile Thr Gly Thr Leu Lys Arg Pro Ser Leu Pro Glu Glu Glu Lys 1250 1255 1260 Leu Lys Leu Ala His Ala Lys Gly Pro Pro Thr Asn Phe Asn Ser 1265 1270 1275 Leu Pro Ala Asn Val Ser Lys Leu His Leu His Gly Ser Pro Arg 1280 1285 1290 Tyr Pro Gly Gly Pro Leu Pro Asp Phe Pro Asn His Ser Leu Thr 1295 1300 1305 Leu Lys Arg Asp Lys Ala Pro Lys Ser Ser Phe Val Gly Asp Gly 1310 1315 1320 Asp Ile Phe Lys Lys Leu Asp Ser Glu Leu Ser Arg Ala Gln Glu 1325 1330 1335 Lys Ala Leu Asp Thr Ser Tyr Val Ile Leu Pro Thr Ala Thr Ala 1340 1345 1350 Thr Leu Arg Pro Lys Pro Lys Glu Glu Pro Lys Tyr Ser Ile His 1355 1360 1365 Ile Asp Gln Met Pro Gln Thr Arg Leu Ile His Leu Ser Thr Ala 1370 1375 1380 Pro Glu Ala Ser Leu Pro Ala Arg Ser Pro Pro Ser Arg Gln Pro 1385 1390 1395 Pro Ser Gly Gly Pro Pro Glu Ala Pro Pro Ala Gln Pro Pro Pro 1400 1405 1410 Pro Pro Pro Pro Pro Pro Pro Pro Pro Gln Gln Pro Leu Pro Pro 1415 1420 1425 Pro Pro Asn Leu Glu Pro Ala Pro Pro Ser Leu Gly Asp Pro Gly 1430 1435 1440 Glu Pro Ala Ala His Pro Gly Pro Ser Thr Gly Pro Ser Thr Lys 1445 1450 1455 Asn Glu Asn Val Ala Thr Leu Ser Val Ser Ser Leu Glu Arg Arg 1460 1465 1470 Lys Ser Arg Tyr Ala Glu Leu Asp Phe Glu Lys Ile Met His Thr 1475 1480 1485 Arg Lys Arg His Gln Asp Met Phe Gln Asp Leu Asn Arg Lys Leu 1490 1495 1500 Gln His Ala Ala Glu Lys Asp Lys Glu Val Leu Gly Pro Asp Ser 1505 1510 1515 Lys Pro Glu Lys Gln Gln Thr Pro Asn Lys Arg Pro Trp Glu Ser 1520 1525 1530 Leu Arg Lys Ala His Gly Thr Pro Thr Trp Val Lys Lys Glu Leu 1535 1540 1545 Glu Pro Leu Gln Pro Ser Pro Leu Glu Leu Arg Ser Val Glu Trp 1550 1555 1560 Glu Arg Ser Gly Ala Thr Ile Pro Leu Val Gly Gln Asp Ile Ile 1565 1570 1575 Asp Leu Gln Thr Glu Val 1580

Claims

1. An antibody or an antigen-binding fragment thereof that binds to human adhesion G protein-coupled receptor B1 protein, wherein the antibody or antigen-binding fragment thereof comprises: The first complementarity determination region V in a variable heavy chain H -CDR1, the second complementarity-determining region V in variable heavy chains H -CDR2, the third complementarity-determining region V in variable heavy chains H -CDR3, the first complementarity-determining region V in the variable light chain L -CDR1, the second complementarity-determining region V in the variable light chain L -CDR2 and the third complementary determinant region V in the variable light chain L -CDR3; where: The V H The amino acid sequence of -CDR1 is SEQ ID NO: 7; The V H The amino acid sequence of -CDR2 is SEQ ID NO: 8; The V H The amino acid sequence of -CDR3 is SEQ ID NO: 9; The V L The amino acid sequence of -CDR1 is SEQ ID NO: 10; The V L The amino acid sequence of -CDR2 is SEQ ID NO: 11; and The V L The amino acid sequence of -CDR3 is SEQ ID NO:

12.

2. The antibody or antigen-binding fragment thereof according to claim 1, wherein the antibody or antigen-binding fragment thereof comprises a variable heavy chain and a variable light chain, the variable heavy chain comprising the amino acid sequence of SEQ ID NO: 1, and the variable light chain comprising the amino acid sequence of SEQ ID NO:

4.

3. The antibody or its antigen-binding fragment according to claim 1, wherein the antibody is an IgM or IgG antibody.

4. The antibody or antigen-binding fragment thereof according to claim 1, wherein the antibody or antigen-binding fragment thereof is humanized.

5. The antibody or antigen-binding fragment thereof according to claim 4, wherein the humanized antibody or antigen-binding fragment thereof comprises a heavy chain and a light chain.

6. The antibody or antigen-binding fragment thereof according to claim 5, wherein the heavy chain comprises the amino acid sequence of SEQ ID NO: 13, and the light chain comprises the amino acid sequence of SEQ ID NO:

14.

7. The antibody or antigen-binding fragment thereof according to claim 1, wherein the antibody or antigen-binding fragment thereof is conjugated to the effector moiety.

8. The antibody or antigen-binding fragment thereof according to claim 7, wherein the effector portion is a detectable marker, a cytotoxic agent, a chemotherapeutic agent, or a nucleic acid molecule.

9. The antibody or antigen-binding fragment thereof according to claim 8, wherein each antibody or antigen-binding fragment thereof contains 3 to 5 maytansine alkaloid molecules.

10. The antibody or antigen-binding fragment thereof according to claim 1, wherein the antigen-binding fragment is Fab, F(ab')2, Fv, scFv, scFv-Fc, a double-chain antibody or a microantibody.

11. A pharmaceutical composition comprising an antibody or an antigen-binding fragment thereof according to any one of claims 1 to 10 and a pharmaceutically acceptable carrier.

12. An isolated nucleic acid molecule encoding an antibody or an antigen-binding fragment thereof according to any one of claims 1 to 10.

13. The isolated nucleic acid molecule according to claim 12, wherein the nucleic acid sequence encoding the variable heavy chain of the antibody or its antigen-binding fragment comprises the nucleotide sequence of SEQ ID NO: 2 or SEQ ID NO: 3, and the nucleic acid sequence encoding the variable light chain of the antibody or its antigen-binding fragment comprises the nucleotide sequence of SEQ ID NO: 5 or SEQ ID NO:

6.

14. A vector comprising the nucleic acid molecule according to claim 13.

15. A host cell transformed with the vector according to claim 14.

16. Use of the antibody or antigen-binding fragment thereof according to any one of claims 1 to 10 in the preparation of a diagnostic agent for detecting cells expressing BAI1.

17. A method for detecting cells expressing BAI1 for non-diagnostic purposes, the method comprising contacting the cells with an antibody or an antigen-binding fragment thereof according to any one of claims 1 to 10, and detecting the antibody or the antigen-binding fragment thereof.

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