LILRB3-binding molecules and uses thereof

Abstract

The present invention provides novel anti-LILRB3 antibodies, pharmaceutical compositions containing such antibodies, and therapeutic methods using such antibodies and pharmaceutical compositions for the treatment of diseases such as cancer, autoimmune diseases, or allergic inflammation. The present invention can also be used to regulate osteoclast differentiation.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of priority to U.S. Provisional Application No. 62 / 794,064, filed January 18, 2019, the contents of which are expressly incorporated herein in their entirety for all purposes.

[0002] Sequence Listing This application contains a Sequence Listing that has been submitted electronically in ASCII format and is incorporated herein by reference in its entirety. The ASCII copy, created on January 15, 2020, is named 011506-5022_ST25.txt and is 72 kilobytes in size.

[0003] The present disclosure relates to antibodies that specifically bind to LILRB3, for example, human LILRB3 (hLILRB3), and pharmaceutical compositions thereof that include such LILRB3-binding antibodies. Methods of using the antibodies of the present invention to detect human LILRB3 or modulate human LILRB3 activity in the treatment of various diseases, including inflammatory diseases, autoimmune diseases, and cancer, are also included in the present invention. [Background technology]

[0004] The human leukocyte Ig-like receptor (LILR) family belongs to a superfamily of paired receptors that may transmit stimulatory or inhibitory signals depending on the presence or absence of tyrosine-based signaling motifs in the cytoplasmic tail. Human LILRs consist of five stimulatory receptors (LILRA1-5), six inhibitory receptors (LILRB1-6), and two pseudogenes. LILRs are expressed in various cells, including lymphoid and myeloid cells, and the expression patterns of each receptor are different. Polymorphisms and copy number variation contribute to human diversity. In general, LILR activity causes up- or down-regulation of both innate and adaptive immune functions, with various effects on different cell types. Recent studies have found that several LILRB family members are expressed by cancer cells, especially hematopoietic cancer cells, and may support cancer initiation and recurrence, as well as cancer stem cell activity.

[0005] Human LILRB3 (also called CD85A, ILT5, LIR3, or HL9) contains four extracellular immunoglobulin domains, a transmembrane domain, and four cytoplasmic immunoreceptor tyrosine-based inhibitory motifs (ITIMs). Expression of LILRB3 has been reported in monocytes, monocyte-derived osteoclasts, granulocytes, dendritic cells, osteoclasts, and precursor mast cells. No ligand for LILRB3 has been identified, and little is known about the function of LILRB3. Taken together, these findings suggest that the development of drugs useful for modulating signaling from LILRB3 would be highly beneficial in diseases involving immune system dysregulation, including inflammatory diseases, autoimmune diseases, and cancer. Summary of the Invention

[0006] In one aspect, the present invention relates to novel anti-LILRB3 antibodies. In some embodiments, the anti-LILRB3 antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:1 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:2. In some embodiments, the anti-LILRB3 antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:3 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:4. In some embodiments, the anti-LILRB3 antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:5 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:6. In some embodiments, the anti-LILRB3 antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:7 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:8. In some embodiments, the anti-LILRB3 antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:9 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:10. In some embodiments, the anti-LILRB3 antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:11 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:12. In some embodiments, the anti-LILRB3 antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 13 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 14. In some embodiments, the anti-LILRB3 antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 15 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 16. In some embodiments, the anti-LILRB3 antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 17 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 18. In some embodiments, the anti-LILRB3 antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 19 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 20. In some embodiments, the anti-LILRB3 antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 21 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 22. In some embodiments, the anti-LILRB3 antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 23 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 24. In some embodiments, the anti-LILRB3 antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:25 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:26.

[0007] In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO:27, a vhCDR2 comprising SEQ ID NO:28, a vhCDR3 comprising SEQ ID NO:29, a vlCDR1 comprising SEQ ID NO:30, a vlCDR2 comprising SEQ ID NO:31, and a vlCDR3 comprising SEQ ID NO:32. In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO:33, a vhCDR2 comprising SEQ ID NO:34, a vhCDR3 comprising SEQ ID NO:35, a vlCDR1 comprising SEQ ID NO:36, a vlCDR2 comprising SEQ ID NO:37, and a vlCDR3 comprising SEQ ID NO:38. In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO:39, a vhCDR2 comprising SEQ ID NO:40, a vhCDR3 comprising SEQ ID NO:41, a vlCDR1 comprising SEQ ID NO:42, a vlCDR2 comprising SEQ ID NO:43, and a vlCDR3 comprising SEQ ID NO:44. In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO: 45, a vhCDR2 comprising SEQ ID NO: 46, a vhCDR3 comprising SEQ ID NO: 47, a vlCDR1 comprising SEQ ID NO: 48, a vlCDR2 comprising SEQ ID NO: 49, and a vlCDR3 comprising SEQ ID NO: 50. In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO: 51, a vhCDR2 comprising SEQ ID NO: 52, a vhCDR3 comprising SEQ ID NO: 53, a vlCDR1 comprising SEQ ID NO: 54, a vlCDR2 comprising SEQ ID NO: 55, and a vlCDR3 comprising SEQ ID NO: 56. In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO: 57, a vhCDR2 comprising SEQ ID NO: 58, a vhCDR3 comprising SEQ ID NO: 59, a vlCDR1 comprising SEQ ID NO: 60, a vlCDR2 comprising SEQ ID NO: 61, and a vlCDR3 comprising SEQ ID NO: 62. In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO: 63, a vhCDR2 comprising SEQ ID NO: 64, a vhCDR3 comprising SEQ ID NO: 65, a vlCDR1 comprising SEQ ID NO: 66, a vlCDR2 comprising SEQ ID NO: 67, and a vlCDR3 comprising SEQ ID NO: 68. In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO: 69, a vhCDR2 comprising SEQ ID NO: 70, a vhCDR3 comprising SEQ ID NO: 71, a vlCDR1 comprising SEQ ID NO: 72, a vlCDR2 comprising SEQ ID NO: 73, and a vlCDR3 comprising SEQ ID NO: 74.In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO: 75, a vhCDR2 comprising SEQ ID NO: 76, a vhCDR3 comprising SEQ ID NO: 77, a vlCDR1 comprising SEQ ID NO: 78, a vlCDR2 comprising SEQ ID NO: 79, and a vlCDR3 comprising SEQ ID NO: 80. In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO: 81, a vhCDR2 comprising SEQ ID NO: 82, a vhCDR3 comprising SEQ ID NO: 83, a vlCDR1 comprising SEQ ID NO: 84, a vlCDR2 comprising SEQ ID NO: 85, and a vlCDR3 comprising SEQ ID NO: 86. In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO: 87, a vhCDR2 comprising SEQ ID NO: 88, a vhCDR3 comprising SEQ ID NO: 89, a vlCDR1 comprising SEQ ID NO: 90, a vlCDR2 comprising SEQ ID NO: 91, and a vlCDR3 comprising SEQ ID NO: 92. In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO: 93, a vhCDR2 comprising SEQ ID NO: 94, a vhCDR3 comprising SEQ ID NO: 95, a vlCDR1 comprising SEQ ID NO: 96, a vlCDR2 comprising SEQ ID NO: 97, and a vlCDR3 comprising SEQ ID NO: 98. In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO: 99, a vhCDR2 comprising SEQ ID NO: 100, a vhCDR3 comprising SEQ ID NO: 101, a vlCDR1 comprising SEQ ID NO: 102, a vlCDR2 comprising SEQ ID NO: 103, and a vlCDR3 comprising SEQ ID NO: 104.

[0008] In some embodiments, the anti-LILRB3 antibodies described herein bind to human LILRB3.

[0009] In another aspect, the invention relates to a nucleic acid composition encoding any one of the anti-LILRB3 antibodies described herein.

[0010] Another aspect of the invention relates to an expression vector composition comprising any one of the nucleic acid compositions described herein. In some embodiments, the first nucleic acid is comprised in a first expression vector and the second nucleic acid is comprised in a second expression vector. In some other embodiments, the first nucleic acid and the second nucleic acid are comprised in a single expression vector.

[0011] Another aspect of the present invention relates to a host cell comprising any one of the expression vectors described herein.A method for producing an anti-LILRB3 antibody is also provided, which comprises culturing a host cell under conditions in which the antibody is expressed, and recovering the antibody.

[0012] In another aspect, the invention relates to a composition comprising any one of the anti-LILRB3 antibodies described herein and a pharma- ceutically acceptable carrier or diluent.

[0013] Also described are methods of modulating an immune response in a subject, the method comprising administering to the subject an effective amount of any one of the anti-LILRB3 antibodies described herein, or any one of the compositions described herein. In some embodiments, the method comprises administering to the subject an effective amount of an anti-LILRB3 antibody that functions as a LILRB3 antagonist, or a pharmaceutical composition thereof. In some embodiments, the method comprises administering to the subject an effective amount of an anti-LILRB3 antibody that functions as a LILRB3 agonist, or a pharmaceutical composition thereof.

[0014] In another aspect, the present invention relates to a method of treating cancer in a subject, the method comprising administering to the subject an effective amount of an anti-LILRB3 antibody described herein or any one of the compositions described herein. In some embodiments, the cancer being treated upregulates LILRB3 compared to corresponding non-cancerous tissue. In some embodiments, the subject being treated expresses high levels of LILRB3 on hematopoietic cells. The cancer being treated can be any cancer. In some embodiments, the anti-LILRB3 antibody is used in combination with one or more additional therapeutic agents to treat cancer. In some embodiments, such anti-cancer therapeutic agents are other immune checkpoint inhibitors such as ipilimumab, nivolumab, pembrolizumab, avelumab, durvalumab, and atezolizumab.

[0015] In another aspect, the invention relates to a method of treating an autoimmune disease in a subject, the method comprising administering to the subject an effective amount of any one of the anti-LILRB3 antibodies described herein, or any one of the compositions described herein.

[0016] In another aspect, the invention relates to a method of treating an autoimmune disease in a subject, the method comprising administering to the subject an effective amount of an anti-LILRB3 antibody described herein, or any one of the compositions described herein.

[0017] In a further aspect, the invention relates to a method of treating allergic inflammation in a subject, the method comprising administering to the subject an effective amount of any one of the anti-LILRB3 antibodies described herein, or any one of the compositions described herein.

[0018] In a further aspect, the invention relates to a method for modulating osteoclast differentiation, the method comprising administering to a subject an effective amount of any one of the anti-LILRB3 antibodies described herein, or any one of the compositions described herein.

[0019] The invention is best understood from the following detailed description when read in conjunction with the accompanying drawing figures, in which: [Brief description of the drawings]

[0020] [Figure 1A] FIG. 1A shows LILBR3 surface expression on various hematopoietic subsets using flow cytometry. [Figure 1B] FIG. 1B shows LILBR3 surface expression on various hematopoietic subsets using flow cytometry. [Diagram 2] FIG. 2 shows the effect of LILRB3 antibody or LILRB3-Fc protein on T cell responsiveness in the primary mixed lymphocyte reaction (MLR). [Figure 3A]FIG. 3 shows the ability of PBMCs to modulate surface expression of activation markers in response to T cell stimulation following incubation with LILRB3 7C5 antibody. [Figure 3B] FIG. 3 shows the ability of PBMCs to modulate surface expression of activation markers in response to T cell stimulation following incubation with LILRB3 7C5 antibody. [Figure 4] FIG. 4 shows the effect of LILRB3 7C5 antibody on cytokine production by PBMCs in response to T cell stimulation. [Diagram 5] FIG. 5 shows cytokine release in unstimulated blood upon incubation with LILRB3 7C5 antibody. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The present disclosure provides novel anti-LILRB3 antibodies. In some embodiments, the anti-LILRB3 antibodies act to regulate immune responses in a subject, for example, to treat cancer or an autoimmune disease. In some embodiments, the anti-LILRB3 antibodies act to treat allergic inflammation. In some embodiments, the anti-LILRB3 antibodies regulate osteoclast differentiation.

[0022] To facilitate the understanding of this invention, several terms and phrases are defined below.

[0023] As used herein, each of the following terms has the meaning associated with it in this section.

[0024] The articles "a" and "an" are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. By way of example, "an element" means one element or more than one element.

[0025] As used herein, "about" when referring to a measurable value, such as an amount or temporal duration, is meant to encompass a ±20% or ±10% variation, more preferably a ±5% variation, even more preferably a ±1% variation, and even more preferably a ±0.1% variation from the specified value, where such variations are appropriate for performing the disclosed methods.

[0026] As used herein, "antigen binding domain" or "ABD" refers to a set of six complementarity determining regions (CDRs) that, when present as part of a polypeptide sequence, specifically bind to a target antigen as discussed herein. Thus, an "antigen binding domain" binds to a target antigen as outlined herein. As known in the art, these CDRs are generally present as a first set of variable heavy chain CDRs (vhCDRs or VHCDRs or CDR-HC) and a second set of variable light chain CDRs (vlCDRs or VLCDRs or CDR-LC), each of which comprises three CDRs, namely vhCDR1, vhCDR2, vhCDR3 for the heavy chain, and vlCDR1, vlCDR2, and vlCDR3 for the light chain. The CDRs are present in the variable heavy chain domain and the variable light chain domain, respectively, and together form the Fv region. Thus, in some cases, the six CDRs of the antigen binding domain are provided by the variable heavy chain and the variable light chain. In the "Fab" format, the set of six CDRs is provided by two distinct polypeptide sequences, a variable heavy domain (vh or VH; comprising vhCDR1, vhCDR2 and vhCDR3) and a variable light domain (vl or VL; comprising vlCDR1, vlCDR2 and vlCDR3), with the C-terminus of the vh domain attached to the N-terminus of the CH1 domain of the heavy chain and the C-terminus of the vl domain attached to the N-terminus of the constant light domain (thereby forming the light chain). In the scFv format, the VH and VL domains are covalently linked into a single polypeptide sequence, typically by the use of a linker, as outlined herein, which may be either (starting from the N-terminus) vh-linker-vl or vl-linker-vh, with the former generally being preferred (with optional domain linkers on either side depending on the format used).As understood in the art, the CDRs are separated by respective framework regions of the variable heavy and variable light domains, where for the light variable region these are FR1-vlCDR1-FR2-vlCDR2-FR3-vlCDR3-FR4, and for the heavy variable region these are FR1-vhCDR1-FR2-vhCDR2-FR3-vhCDR3-FR4, the framework regions showing high identity to human germline sequences. Antigen binding domains of the present invention include Fab, Fv and scFv.

[0027] The term "antibody" is used in the broadest sense and includes, for example, intact immunoglobulins or antigen-binding portions. Antigen-binding portions may be produced by recombinant DNA techniques or by enzymatic or chemical cleavage of intact antibodies. Thus, the term antibody includes conventional tetrameric antibodies consisting of two heavy and two light chains, as well as antigen-binding fragments such as Fv, Fab, scFv, etc. In some cases, the invention provides bispecific antibodies comprising at least one antigen-binding domain as outlined herein.

[0028] "Modification" herein means substitution, insertion, and / or deletion of an amino acid in a polypeptide sequence, or modification to a moiety chemically linked to a protein. For example, a modification may be an altered carbohydrate or PEG structure attached to a protein. "Amino acid modification" herein means substitution, insertion, and / or deletion of an amino acid in a polypeptide sequence. For clarity, unless otherwise stated, amino acid modifications are always to amino acids encoded by DNA, e.g., the 20 amino acids for which DNA and RNA have codons.

[0029] "Amino acid substitution" or "substitution" herein refers to replacing an amino acid at a particular position in a parent polypeptide sequence with a different amino acid. In particular, in some embodiments, the substitution is for an amino acid that does not naturally occur (either not naturally occurring in an organism or not occurring in any organism) at the particular position. For example, the substitution M252Y refers to a variant polypeptide, in this case an Fc variant, in which the methionine at position 252 is replaced with a tyrosine. For clarity, a protein that has been engineered to change the nucleic acid coding sequence but not the starting amino acid (e.g., replacing CGG (which codes for arginine) with CGA (which still codes for arginine) to increase host organism expression levels) is not an "amino acid substitution". That is, if the protein has the same amino acid at the particular position where it starts, despite the creation of a new gene that codes for the same protein, it is not an amino acid substitution.

[0030] As used herein, "variant protein" or "protein variant" or "variant" refers to a protein that differs from that of a parent protein based on at least one amino acid modification. A protein variant may refer to the protein itself, a composition comprising the protein, or an amino acid sequence encoding it. Preferably, a protein variant has at least one amino acid modification compared to the parent protein, e.g., about 1 to about 70 amino acid modifications compared to the parent, and preferably about 1 to about 5 amino acid modifications. As described below, in some embodiments, the parent polypeptide, e.g., an Fc parent polypeptide, is a human wild-type sequence, such as an Fc region from IgG1, IgG2, IgG3, or IgG4. The sequence of the protein variant herein preferably has at least about 80% identity to the parent protein sequence, most preferably at least about 90% identity, and more preferably at least about 95%-98%-99% identity. A variant protein may refer to the variant protein itself, a composition comprising the protein variant, or a DNA sequence encoding it.

[0031] Thus, as used herein, "antibody variant" or "variant antibody" refers to an antibody that differs from a parent antibody by virtue of at least one amino acid modification, and as used herein, "IgG variant" or "variant IgG" refers to an antibody that differs from a parent IgG (again, often derived from human IgG) by virtue of at least one amino acid modification, and as used herein, "immunoglobulin variant" or "variant immunoglobulin" refers to an immunoglobulin sequence that differs from that of a parent immunoglobulin sequence by virtue of at least one amino acid modification. As used herein, "Fc variant" or "variant Fc" refers to a protein that comprises an amino acid modification in the Fc domain. The Fc variants of the present invention are defined according to the amino acid modifications that compose them. Thus, for example, M252Y or 252Y is an Fc variant with a substitution serine at position 252 relative to the parent Fc polypeptide, where the numbering is according to the EU index. Similarly, M252Y / S254T / T256E defines an Fc variant with substitutions M252Y, S254T, and T256E relative to the parent Fc polypeptide. The identity of the wild type amino acids may not be specified, in which case the variant is referred to as 252Y / 254T / 256E. It is understood that the order in which the substitutions are provided is arbitrary, in other words, for example, 252Y / 254T / 256E is the same Fc variant as 254T / 252Y / 256E. For all positions discussed in the present invention related to antibodies, unless otherwise stated, the numbering of amino acid positions is according to Kabat for the numbering of variable regions and according to EU index for constant regions, including Fc regions. EU index, or EU index similar to Kabat or EU numbering scheme, refers to EU antibody numbering (Edelman et al., 1969, Proc Natl Acad Sci USA 63:78-85, incorporated herein by reference in its entirety). Modifications can be additions, deletions, or substitutions. Substitutions can include naturally occurring amino acids and, in some cases, synthetic amino acids.

[0032] As used herein, "protein" means at least two covalently attached amino acids, including proteins, polypeptides, oligopeptides, and peptides. Peptidyl groups include naturally occurring amino acids and peptide bonds.

[0033] As used herein, "Fab" or "Fab region" refers to a polypeptide comprising the VH, CH1, VL, and CL immunoglobulin domains. Fab may refer to this region in isolation, or this region in the context of a full-length antibody, an antibody fragment, or a Fab fusion protein. As used herein, "Fv" or "Fv fragment" or "Fv region" refers to a polypeptide comprising the VL and VH domains of a single antibody binding region (ABD). As will be appreciated by those skilled in the art, these are generally composed of two chains or can be combined (generally via a linker as discussed herein) to form an scFv.

[0034] As used herein, "amino acid" and "amino acid identity" refer to one of the 20 naturally occurring amino acids encoded by DNA and RNA.

[0035] "Parent polypeptide" as used herein refers to a starting polypeptide that is subsequently modified to generate a variant. A parent polypeptide may be a naturally occurring polypeptide, or a variant or modified version of a naturally occurring polypeptide. A parent polypeptide may refer to the polypeptide itself, a composition that includes the parent polypeptide, or the amino acid sequence that encodes it. Thus, a "parent immunoglobulin" as used herein refers to an unmodified immunoglobulin polypeptide that is modified to generate a variant, and a "parent antibody" as used herein refers to an unmodified antibody that is modified to generate a variant antibody. It is noted that "parent antibodies" include known commercially available recombinantly produced antibodies, as outlined below.

[0036] By "heavy chain constant region" herein is meant the CH1-hinge-CH2-CH3 portion of an antibody, typically derived from human IgG1, human IgG2, or human IgG4.

[0037] As used herein, "target antigen" refers to a molecule to which the variable region of a given antibody specifically binds. In this case, the target antigen is the LILRB3 protein.

[0038] As used herein, "target cell" means a cell that expresses a target antigen.

[0039] As used herein, "variable region" refers to a region of an immunoglobulin that is substantially encoded by either a Vκ (V.kappa) gene, a Vλ (V.lambda) gene, and / or a VH gene, each of which contains one or more Ig domains that constitute the kappa immunoglobulin locus, the lambda immunoglobulin locus, and the heavy chain immunoglobulin locus.

[0040] "Wild-type or WT" herein refers to an amino acid or nucleotide sequence found in nature, including allelic variations. A WT protein has an amino acid or nucleotide sequence that has not been intentionally modified.

[0041] "Position" as used herein means a location in a sequence of a protein. Positions may be numbered sequentially or according to established formats, such as the EU index for antibody numbering.

[0042] As used herein, "residue" refers to a position in a protein and its associated amino acid identity. For example, asparagine 297 (also referred to as Asn297 or N297) is the residue at position 297 in the protein sequence.

[0043] The antibodies of the invention are typically recombinant, meaning that the antibody is produced using recombinant nucleic acid techniques in an exogenous host cell.

[0044] "Percent (%) amino acid sequence identity" with respect to protein sequences is defined as the percentage of amino acid residues in a candidate sequence that are identical to amino acid residues in a particular (parent) sequence after aligning the sequences to achieve the maximum percent sequence identity, introducing gaps if necessary, and not considering any conservative substitutions as part of the sequence identity. Alignment to determine percent amino acid sequence identity can be accomplished in a variety of ways that are within the skill of the art, for example, using publicly available computer software such as BLAST, BLAST-2, ALIGN, or Megalign (DNASTAR) software. Those skilled in the art can determine appropriate parameters for measuring alignment, including any algorithms required to achieve maximum alignment over the entire length of the sequences being compared. One particular program is the ALIGN-2 program, as outlined in paragraphs

[0279] to

[0280] of US Patent Application Publication No. 2016 / 0244525, which is incorporated herein by reference. Another approximate alignment of nucleic acid sequences is provided by the local homology algorithm of Smith and Waterman, Advances in Applied Mathematics, 2:482-489 (1981). This algorithm can be applied to amino acid sequences by using a scoring matrix developed by Dayhoff, Atlas of Protein Sequences and Structure, MO Dayhoff ed., 5suppl.3:353-358, National Biomedical Research Foundation, Washington, DC, USA, and normalized by Gribskov, Nucl.Acids Res.14(6):6745-6763 (1986).

[0045] An example implementation of this algorithm for determining percent identity of sequences is provided by the Genetics Computer Group (Madison, Wis.) in the "BestFit" utility application. The default parameters for this method are described in the Wisconsin Sequence Analysis Package Program Manual, Version 8 (1995), available from the Genetics Computer Group (Madison, Wis.). Another way to establish percent identity in the context of the present invention is to use the MPSRCH package of programs copyrighted by the University of Edinburgh, developed by John F. Collins and Shane S. Sturrok, and distributed by IntelliGenetics, Inc. (Mountain View, Calif.). From this set of packages, the Smith-Waterman algorithm can be used with default parameters for the scoring table (e.g., gap open penalty 12, gap extension penalty 1, gap 6). From the data generated, the "match" value reflects the "sequence ID". Other suitable programs for calculating percent identity or similarity between sequences are generally known in the art, for example, another alignment program is BLAST used with default parameters. For example, BLASTN and BLASTP can be used with the following default parameters:filter=none;strand=both;cutoff=60;expect=10;Matrix=BLOSUM62;Descriptions=50 sequences;sort by=HIGH SCORE;Databases=non-redundant,GenBank+EMBL+DDBJ+PDB+GenBank CDS translations+Swiss protein+Spupdate+PIR.Details of these programs can be found at the Internet address blast.ncbi.nlm.nih.gov / Blast.cgi, which can be retrieved by preceding it with http: / / .

[0046] The degree of identity between an amino acid sequence of the present invention ("sequence of the present invention") and a parent amino acid sequence is calculated as the number of exact matches in an alignment of the two sequences, divided by the length of the "sequence of the present invention" or the length of the parent sequence, whichever is shorter. The result is expressed as a percentage identity.

[0047] In some embodiments, the two or more amino acid sequences are at least 50%, 60%, 70%, 80%, or 90% identical, hi some embodiments, the two or more amino acid sequences are at least 95%, 97%, 98%, 99%, or even 100% identical.

[0048] "Specific binding" to a particular antigen or epitope, or "specifically binds to" or "specific for" a particular antigen or epitope, refers to binding that is measurably different from non-specific interactions. Specific binding can be measured, for example, by determining the binding of a molecule compared to the binding of a control molecule, which is generally a molecule of similar structure that has no binding activity. For example, specific binding can be determined by competition with a control molecule that is similar to the target.

[0049] As used herein, the term "Ka" or "Ka" is intended to refer to the association rate of a particular antibody-antigen interaction, while the term "Kdis" or "Kd" is intended to refer to the dissociation rate of a particular antibody-antigen interaction. D The term "dissociation constant" is intended to refer to the ratio of Kd to Ka (i.e., Kd / Ka) and expressed as a molar concentration (M). D Values ​​can be determined using methods well established in the art. In some embodiments, the K D A method for determining the K of an antibody is through the use of surface plasmon resonance, for example, through the use of a biosensor system such as a BIACORE® system. In some embodiments, the K of an antibody is D is determined by biolayer interferometry. In some embodiments, K D In another embodiment, the K D The K value is measured with an immobilized antibody (e.g., a parent mouse antibody, a chimeric antibody, or a humanized antibody variant). D The K value is measured in bivalent binding mode. D Values ​​are measured in the monovalent binding mode.

[0050] "Disease" includes a condition in the health of an animal, including a human, in which the animal is unable to maintain homeostasis and the animal's health continues to deteriorate if the disease is not ameliorated.

[0051] On the other hand, a "disorder" in an animal, including a human, includes a state of health in which the animal is able to maintain homeostasis but in which the animal's state of health is less favorable than it would be in the absence of the disorder. If left untreated, the disorder does not necessarily result in an animal's state of health being further impaired.

[0052] The terms "treatment", "treating", "treating" and the like refer to obtaining a desired pharmacological and / or physiological effect. This effect may be preventative in that it completely or partially prevents or reduces the likelihood of a disease or its symptoms, and / or it may be therapeutic in that it partially or completely cures the disease and / or side effects caused by the disease. As used herein, "treatment" encompasses any treatment of a disease in a mammal, particularly a human, and includes (a) preventing the disease from occurring in a subject who may be susceptible to the disease but has not yet been diagnosed as having the disease, (b) inhibiting the disease, i.e., arresting the development or progression of the disease, and (c) palliating the disease, i.e., causing regression of the disease and / or reducing one or more disease symptoms. "Treatment" is also meant to encompass delivery of an agent to provide a pharmacological effect, even in the absence of disease or symptoms. For example, "treatment" encompasses delivery of a composition capable of eliciting an immune response or conferring immunity in the absence of a pathology, e.g., in the case of a vaccine.

[0053] As used herein, the term "mammal" refers to any mammal, including, but not limited to, rodent mammals, such as mice and hamsters, and rabbit mammals, such as rabbits. In some embodiments, the mammal is from the order Carnivora, including felines (cats) and canines (dogs). In some embodiments, the mammal is from the order Artiodactyla, including bovines (cows) and porcines (pigs), or from the order Equines (horses). Most preferably, the mammal is from the order Primates, Ceboids, or Simoids (monkeys), or the order Anthropoids (humans and apes). In some embodiments, the mammal is a human. In some embodiments, the mammal is a cynomolgus monkey.

[0054] The term "regression" as used herein, and words derived therefrom, does not necessarily mean 100% or complete regression. Rather, there are various degrees of regression that one of skill in the art would recognize as having potential benefit or therapeutic effect. In this regard, the disclosed methods can provide any amount, any level of regression of cancer in a mammal. Furthermore, the regression provided by the methods of the invention can include regression of one or more conditions or symptoms of a disease (e.g., cancer). Also, as used herein, "regression" can include delaying the onset of a disease, delaying the onset of a symptom, and / or delaying the onset of the condition. With respect to progressive diseases and disorders, "regression" can include delaying the progression of a disease or disorder, delaying the progression of a symptom of a disease or disorder, and / or delaying the progression of the condition.

[0055] An "effective amount" or "therapeutically effective amount" of a composition includes an amount of the composition sufficient to provide a beneficial effect to a subject to which the composition is administered. An "effective amount" of a delivery vehicle includes an amount sufficient to effectively bind or deliver the composition.

[0056] "Individual" or "host" or "subject" or "patient" means any mammalian subject for whom diagnosis, treatment, or therapy is desired, particularly humans. Other subjects may include cynomolgus monkeys, cows, dogs, cats, guinea pigs, rabbits, rats, mice, horses, etc.

[0057] The term "in combination with" as used herein refers to use when a first treatment is administered during the entire course of administration of a second treatment, and when a first treatment is administered during an overlapping period with administration of a second treatment, such as when administration of a first treatment is initiated before administration of a second treatment and the administration of the first treatment is terminated before administration of the second treatment is terminated, when administration of a second treatment is initiated before administration of a first treatment and the administration of the second treatment is terminated before administration of the first treatment is terminated, when administration of a first treatment is initiated before administration of a second treatment begins and the administration of the second treatment is terminated before administration of the first treatment is terminated, when administration of a second treatment is initiated before administration of a first treatment begins and the administration of the first treatment is terminated before administration of the second treatment is terminated. Thus, "in combination with" may also refer to a regimen that includes administration of two or more therapies. As used herein, "in combination with" also refers to administration of two or more therapies, which may be administered in the same or different formulations, by the same or different routes, and in the same or different dosage form types.

[0058] As used herein, the term "allergic inflammation" refers to a localized or generalized hypersensitivity reaction to at least one specific allergen. The symptoms of "allergic inflammation" can vary widely in impact and intensity.

[0059] The term "encode" includes the inherent property of, and biological properties resulting from, a particular nucleotide sequence in a polynucleotide, such as a gene, cDNA, or mRNA, to serve as a template for the synthesis of other polymers and macromolecules in biological processes, either having a defined sequence of nucleotides (i.e., rRNA, tRNA, and mRNA) or a defined sequence of amino acids. Thus, for example, a gene codes for a protein when a protein is produced in a cell or other biological system by transcription and translation of the mRNA corresponding to that gene. Both the coding strand, whose nucleotide sequence is identical to that of the mRNA sequence and is usually depicted in a sequence listing, and the non-coding strand, which is used as a template for transcription of the gene or cDNA, can be said to code for the protein or other product of that gene or cDNA.

[0060] The term "nucleic acid" includes RNA or DNA molecules having two or more nucleotides in any form, including single-stranded, double-stranded, oligonucleotide or polynucleotide. The term "nucleotide sequence" includes the sequence of nucleotides in an oligonucleotide or polynucleotide in the single-stranded form of a nucleic acid.

[0061] "Nucleic acid construct" refers to a nucleic acid sequence that has been constructed to contain one or more functional units that are not found together in nature. Examples include circular, linear, double-stranded, extrachromosomal DNA molecules (plasmids), cosmids (plasmids containing COS sequences from lambda phage), viral genomes that contain non-naturally occurring nucleic acid sequences, etc.

[0062] The term "operably linked" as used herein includes a polynucleotide in a functional relationship with another polynucleotide, for example, a single-stranded or double-stranded nucleic acid moiety containing two polynucleotides arranged such that at least one of the two polynucleotides can exert a physiological effect characterized thereby on the other in the nucleic acid moiety. As an example, a promoter operably linked to a coding region of a gene can promote transcription of the coding region. The order specified when indicating operably linked is not important. For example, the phrases "a promoter operably linked to a nucleotide sequence" and "a nucleotide sequence operably linked to a promoter" are used interchangeably herein and are considered to be equivalent. In some cases, when the nucleic acid encoding a desired protein further includes a promoter / regulatory sequence, the promoter / regulatory sequence is positioned at the 5' end of the desired protein coding sequence to drive expression of the desired protein in the cell.

[0063] The terms "oligonucleotide", "polynucleotide" and "nucleic acid molecule", used interchangeably herein, refer to polymeric forms of nucleotides of any length, either ribonucleotides or deoxyribonucleotides. Thus, the terms include, but are not limited to, single-stranded, double-stranded or multi-stranded DNA or RNA, genomic DNA, cDNA, DNA-RNA hybrids or polymers containing purine and pyrimidine bases or other naturally occurring bases, chemically or biochemically modified bases, non-natural bases or derivatized nucleotide bases. The backbone of a polynucleotide may contain sugars and phosphate groups (as typically found in RNA or DNA), or modified or substituted sugar or phosphate groups.

[0064] As used herein, the term "osteoclast" refers to large multinucleated cells with abundant acidophilic cytoplasm derived from hematopoietic stem cells, which function in the resorption and removal of bone tissue.

[0065] As used herein, the term "pharmaceutical composition" refers to a combination of an active agent with an inert or active carrier that makes the composition particularly suitable for in vivo or ex vivo diagnostic or therapeutic applications.

[0066] As used herein, the term "pharmaceutical acceptable carrier" refers to any of the standard pharmaceutical carriers, such as phosphate buffered saline, water, emulsions (such as oil / water or water / oil emulsions), and various types of wetting agents. The composition may also include stabilizers and preservatives. For examples of carriers, stabilizers, and adjuvants, see, for example, Martin, Remington's Pharmaceutical Sciences, 15th Ed., Mack Publ Co., Easton, PA

[1975] .

[0067] Throughout the description, where compositions are described as having, comprising, or including certain components, or where processes and methods are described as having, comprising, or including certain steps, it is further contemplated that there are compositions of the invention that consist essentially of or consist of the recited components, and that there are processes and methods of the invention that consist essentially of or consist of the recited processing steps.

[0068] Various aspects of the invention are described in the following sections. However, an aspect of the invention described in a particular section should not be limited to any particular section.

[0069] I. Antibodies The present disclosure provides novel anti-LILRB3 antibodies. Such antibodies bind to and / or affect the functional properties of human LILRB3. Table 1 lists peptide sequences of heavy and light chain variable regions of LILRB3 antibodies in combination as shown in Table 1. In some embodiments, the heavy and light chain variable regions are arranged in Fab format. In some embodiments, the heavy and light chain variable regions are linked together to form a scFv. [Table 1] JPEG0007631203000002.jpg189119 JPEG0007631203000003.jpg189120 JPEG0007631203000004.jpg43121

[0070] In some embodiments, an anti-LILRB3 antibody of the disclosure comprises a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:1, and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:2.

[0071] In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO:27, a vhCDR2 comprising SEQ ID NO:28, a vhCDR3 comprising SEQ ID NO:29, a vlCDR1 comprising SEQ ID NO:30, a vlCDR2 comprising SEQ ID NO:31, and a vlCDR3 comprising SEQ ID NO:32. In some embodiments, one or more of the six CDRs have one, two, three, four or five amino acid modifications. In further embodiments, a single CDR comprises one or two amino acid substitutions and the modified anti-LILRB3 antibody retains binding to human LILRB3.

[0072] In some embodiments, an anti-LILRB3 antibody of the disclosure comprises a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:3, and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:4.

[0073] In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO: 33, a vhCDR2 comprising SEQ ID NO: 34, a vhCDR3 comprising SEQ ID NO: 35, a vlCDR1 comprising SEQ ID NO: 36, a vlCDR2 comprising SEQ ID NO: 37, and a vlCDR3 comprising SEQ ID NO: 38. In further embodiments, a single CDR comprises one or two amino acid substitutions and the modified anti-LILRB3 antibody retains binding to human LILRB3.

[0074] In some embodiments, an anti-LILRB3 antibody of the disclosure comprises a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:5, and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:6.

[0075] In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO: 39, a vhCDR2 comprising SEQ ID NO: 40, a vhCDR3 comprising SEQ ID NO: 41, a vlCDR1 comprising SEQ ID NO: 42, a vlCDR2 comprising SEQ ID NO: 43, and a vlCDR3 comprising SEQ ID NO: 44. In some embodiments, one or more of the six CDRs have one, two, three, four or five amino acid modifications. In further embodiments, a single CDR comprises one or two amino acid substitutions and the modified anti-LILRB3 antibody retains binding to human LILRB3.

[0076] In some embodiments, an anti-LILRB3 antibody of the disclosure comprises a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:7, and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:8.

[0077] In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO: 45, a vhCDR2 comprising SEQ ID NO: 46, a vhCDR3 comprising SEQ ID NO: 47, a vlCDR1 comprising SEQ ID NO: 48, a vlCDR2 comprising SEQ ID NO: 49, and a vlCDR3 comprising SEQ ID NO: 50. In some embodiments, one or more of the six CDRs have one, two, three, four or five amino acid modifications. In further embodiments, a single CDR comprises one or two amino acid substitutions and the modified anti-LILRB3 antibody retains binding to human LILRB3.

[0078] In some embodiments, an anti-LILRB3 antibody of the disclosure comprises a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:9, and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:10.

[0079] In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO:51, a vhCDR2 comprising SEQ ID NO:52, a vhCDR3 comprising SEQ ID NO:53, a vlCDR1 comprising SEQ ID NO:54, a vlCDR2 comprising SEQ ID NO:55, and a vlCDR3 comprising SEQ ID NO:56. In some embodiments, one or more of the six CDRs have one, two, three, four or five amino acid modifications. In further embodiments, a single CDR comprises one or two amino acid substitutions and the modified anti-LILRB3 antibody retains binding to human LILRB3.

[0080] In some embodiments, an anti-LILRB3 antibody of the disclosure comprises a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:11, and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:12.

[0081] In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO: 57, a vhCDR2 comprising SEQ ID NO: 58, a vhCDR3 comprising SEQ ID NO: 59, a vlCDR1 comprising SEQ ID NO: 60, a vlCDR2 comprising SEQ ID NO: 61, and a vlCDR3 comprising SEQ ID NO: 62. In some embodiments, one or more of the six CDRs have one, two, three, four or five amino acid modifications. In further embodiments, a single CDR comprises one or two amino acid substitutions and the modified anti-LILRB3 antibody retains binding to human LILRB3.

[0082] In some embodiments, an anti-LILRB3 antibody of the disclosure comprises a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:13, and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:14.

[0083] In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO: 63, a vhCDR2 comprising SEQ ID NO: 64, a vhCDR3 comprising SEQ ID NO: 65, a vlCDR1 comprising SEQ ID NO: 66, a vlCDR2 comprising SEQ ID NO: 67, and a vlCDR3 comprising SEQ ID NO: 68. In some embodiments, one or more of the six CDRs have one, two, three, four or five amino acid modifications. In further embodiments, a single CDR comprises one or two amino acid substitutions and the modified anti-LILRB3 antibody retains binding to human LILRB3.

[0084] In some embodiments, an anti-LILRB3 antibody of the disclosure comprises a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:15, and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:16.

[0085] In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO:69, a vhCDR2 comprising SEQ ID NO:70, a vhCDR3 comprising SEQ ID NO:71, a vlCDR1 comprising SEQ ID NO:72, a vlCDR2 comprising SEQ ID NO:73, and a vlCDR3 comprising SEQ ID NO:74. In some embodiments, one or more of the six CDRs have one, two, three, four or five amino acid modifications. In further embodiments, a single CDR comprises one or two amino acid substitutions and the modified anti-LILRB3 antibody retains binding to human LILRB3.

[0086] In some embodiments, an anti-LILRB3 antibody of the disclosure comprises a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:17, and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:18.

[0087] In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO: 75, a vhCDR2 comprising SEQ ID NO: 76, a vhCDR3 comprising SEQ ID NO: 77, a vlCDR1 comprising SEQ ID NO: 78, a vlCDR2 comprising SEQ ID NO: 79, and a vlCDR3 comprising SEQ ID NO: 80. In some embodiments, one or more of the six CDRs have one, two, three, four or five amino acid modifications. In further embodiments, a single CDR comprises one or two amino acid substitutions and the modified anti-LILRB3 antibody retains binding to human LILRB3.

[0088] In some embodiments, an anti-LILRB3 antibody of the disclosure comprises a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:19, and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:20.

[0089] In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO: 81, a vhCDR2 comprising SEQ ID NO: 82, a vhCDR3 comprising SEQ ID NO: 83, a vlCDR1 comprising SEQ ID NO: 84, a vlCDR2 comprising SEQ ID NO: 85, and a vlCDR3 comprising SEQ ID NO: 86. In some embodiments, one or more of the six CDRs have one, two, three, four or five amino acid modifications. In further embodiments, a single CDR comprises one or two amino acid substitutions and the modified anti-LILRB3 antibody retains binding to human LILRB3.

[0090] In some embodiments, an anti-LILRB3 antibody of the disclosure comprises a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:21, and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:22.

[0091] In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO: 87, a vhCDR2 comprising SEQ ID NO: 88, a vhCDR3 comprising SEQ ID NO: 89, a vlCDR1 comprising SEQ ID NO: 90, a vlCDR2 comprising SEQ ID NO: 91, and a vlCDR3 comprising SEQ ID NO: 92. In some embodiments, one or more of the six CDRs have one, two, three, four or five amino acid modifications. In further embodiments, a single CDR comprises one or two amino acid substitutions and the modified anti-LILRB3 antibody retains binding to human LILRB3.

[0092] In some embodiments, an anti-LILRB3 antibody of the disclosure comprises a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:23, and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:24.

[0093] In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO: 93, a vhCDR2 comprising SEQ ID NO: 94, a vhCDR3 comprising SEQ ID NO: 95, a vlCDR1 comprising SEQ ID NO: 96, a vlCDR2 comprising SEQ ID NO: 97, and a vlCDR3 comprising SEQ ID NO: 98. In some embodiments, one or more of the six CDRs have one, two, three, four or five amino acid modifications. In further embodiments, a single CDR comprises one or two amino acid substitutions and the modified anti-LILRB3 antibody retains binding to human LILRB3.

[0094] In some embodiments, an anti-LILRB3 antibody of the disclosure comprises a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:25, and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:26.

[0095] In some embodiments, the anti-LILRB3 antibody comprises a vhCDR1 comprising SEQ ID NO: 99, a vhCDR2 comprising SEQ ID NO: 100, a vhCDR3 comprising SEQ ID NO: 101, a vlCDR1 comprising SEQ ID NO: 102, a vlCDR2 comprising SEQ ID NO: 103, and a vlCDR3 comprising SEQ ID NO: 104. In some embodiments, one or more of the six CDRs have one, two, three, four or five amino acid modifications. In further embodiments, a single CDR comprises one or two amino acid substitutions and the modified anti-LILRB3 antibody retains binding to human LILRB3.

[0096] In addition to the sequence variants of the heavy and light chain variable regions and / or CDRs described herein, alterations can be made to the framework regions of the heavy and / or light variable regions. In some embodiments, variants in the framework regions (e.g., excluding the CDRs) retain at least about 80, 85, 90, or 95% identity to the germline sequence. Variants can be made that retain at least about 80, 85, 90, or 95% identity to any one of the light chain V-GENE, light chain J-GENE, heavy chain V-GENE, heavy chain J-GENE, and heavy chain D-GENE alleles.

[0097] In some embodiments, variations are made in framework regions that retain at least 80, 85, 90 or 95% identity to the germline gene sequence while leaving the six CDRs unchanged.

[0098] In some embodiments, variations are made in both framework regions that retain at least 80, 85, 90 or 95% identity to the germline gene sequence. The CDRs may have amino acid modifications (e.g., 1, 2, 3, 4 or 5 amino acid modifications in the set of CDRs (i.e., the CDRs may be modified as long as the total number of changes in the set of 6 CDRs is less than 6 amino acid modifications; any combination of CDRs may be altered, e.g., there may be one modification in vlCDR1, two modifications in vhCDR2, no modifications in vhCDR3, etc.).

[0099] By selecting the amino acid sequences of the CDRs and / or the heavy and light chain variable regions from those described herein and combining them, if necessary, with the amino acid sequences of the framework and / or constant regions of the heavy and light chains of the antibody, one skilled in the art can design an anti-LILRB3 antibody according to the present invention. The framework and / or constant regions (Fc domains) of the antibodies according to the present invention can be derived from any species of antibody, such as human, rabbit, dog, cat, mouse, horse or monkey.

[0100] In some embodiments, the constant region is derived from a human and includes a heavy chain constant region derived from IgG, IgA, IgM, IgE, and IgD subtypes or variants thereof, and a light chain constant region derived from a kappa or lambda subtype or variants thereof. In some embodiments, the heavy chain constant region is derived from human IgG, including IgG1, IgG2, IgG3, and IgG4. In some embodiments, the amino acid sequence of the heavy chain constant region is at least 80%, 85%, 90%, or 95% identical to the constant region of human IgG1, IgG2, IgG3, or IgG4. In some other embodiments, the amino acid sequence of the constant region is at least 80%, 85%, 90%, or 95% identical to an antibody constant region from another mammal, such as rabbit, dog, cat, mouse, horse, or monkey. In some embodiments, the antibody constant region includes a hinge, a CH2 domain, a CH3 domain, and optionally a CH1 domain.

[0101] In some embodiments, the antibodies described herein may be derived from a mixture from different species, for example, forming chimeric and / or humanized antibodies. In general, both "chimeric antibodies" and "humanized antibodies" refer to antibodies that combine regions from two or more species. For example, "chimeric antibodies" traditionally contain variable region(s) from mouse (or, in some cases, rat) and constant region(s) from human. "Humanized antibodies" generally refer to non-human antibodies in which the variable domain framework regions have been swapped with sequences found in human antibodies. Generally, in humanized antibodies, the entire antibody except for the CDRs is encoded by a polynucleotide of human origin or is identical to such an antibody except in its CDRs. CDRs encoded in part or in whole by nucleic acid originating from a non-human organism are grafted onto the beta sheet framework of a human antibody variable region to create an antibody whose specificity is determined by the grafted CDRs. The production of such antibodies is described, for example, in WO 92 / 11018; Jones, 1986, Nature 321:522-525; Verhoeyen et al., 1988, Science 239:1534-1536, all of which are incorporated by reference in their entireties. "Backmutation" of selected acceptor framework residues to the corresponding donor residues is often required to restore affinity lost in the initial grafting construct (U.S. Pat. Nos. 5,530,101; 5,585,089; 5,693,761; 5,693,762; 6,180,370; 5,859,205; 5,821,337; 6,054,297; 6,407,213, all of which are incorporated by reference in their entireties). A humanized antibody also optimally comprises at least a portion of an immunoglobulin constant region, typically that of a human immunoglobulin, e.g., typically comprises a human Fc region. Humanized antibodies can also be produced using mice with genetically engineered immune systems, as described in, for example, Roque et al., 2004, Biotechnol Prog. 20:639-654, incorporated by reference in its entirety.Various techniques and methods for humanizing and reshaping non-human antibodies are well known in the art (see Tsurushita & Vasquez, 2004, Humanization of Monoclonal Antibodies, Molecular Biology of B Cells, 533-545, Elsevier Science (USA), and references cited therein, all of which are incorporated by reference in their entirety). Humanization methods include those described in Jones et al., 1986, Nature 321:522-525; Riechmann et al., 1988, Nature 332:323-329; Verhoeyen et al., 1988, Science 239:1534-1536; Queen et al., 1989, Proc Natl Acad Sci, USA 86:10029-33; He et al., 1998, J. 160:1029-1035; Carter et al., 1992, Proc Natl Acad Sci USA 89:4285-9; Presta et al., 1997, Cancer Res. 57(20):4593-9; Gorman et al., 1991, Proc. Natl. Acad. Sci. USA 88:4181-4185; O'Connor et al., 1998, Protein Eng 11:321-8, all of which are fully incorporated by reference. Other methods of humanizing or reducing the immunogenicity of non-human antibody variable regions can include, for example, the resurfacing method described in Roguska et al., 1994, Proc. Natl. Acad. Sci. USA 91:969-973, all of which are fully incorporated by reference. Other humanization methods can include grafting only portions of the CDRs, including, but not limited to, the methods described in Tan et al., 2002, J. Immunol. 169:1119-1125, and De Pascalis et al., 2002, J. Immunol. 169:3076-3084, all of which are fully incorporated by reference.

[0102] In some embodiments, the antibodies of the invention comprise a heavy chain variable region derived from a particular human germline heavy chain immunoglobulin gene and / or a light chain variable region derived from a particular human germline light chain immunoglobulin gene. Such human antibodies may contain amino acid differences compared to the human germline sequence, for example due to naturally occurring somatic mutations or deliberately introduced site-specific mutations. However, a humanized antibody is typically at least 80% identical in amino acid sequence to an amino acid sequence encoded by a human germline immunoglobulin gene and contains amino acid residues that identify the antibody as derived from a human sequence when compared to the germline immunoglobulin amino acid sequence of another species (e.g., a mouse germline sequence). In certain cases, a humanized antibody may be at least 95, 96, 97, 98, or 99% identical in amino acid sequence to an amino acid sequence encoded by a human germline immunoglobulin gene, or may be at least 96%, 97%, 98%, or 99% identical in amino acid sequence to an amino acid sequence encoded by a human germline immunoglobulin gene. Typically, a humanized antibody derived from a particular human germline sequence will display no more than 10-20 amino acid differences from the amino acid sequence encoded by the human germline immunoglobulin gene, In certain cases, a humanized antibody may display no more than 5 amino acid differences, or even no more than 4, 3, 2, or 1 amino acid differences from the amino acid sequence encoded by the germline immunoglobulin gene.

[0103] In some embodiments, the antibodies of the disclosure are humanized and affinity matured as known in the art. Structure-based methods can be used for humanization and affinity maturation, for example, as described in U.S. Patent No. 7,657,380. Selection-based methods may be used to humanize and / or affinity mature antibody variable regions, including, but not limited to, those described in Wu et al., 1999, J. Mol. Biol. 294:151-162; Baca et al., 1997, J. Biol. Chem. 272(16):10678-10684; Rosok et al., 1996, J. Biol. Chem. 271(37):22611-22618; Rader et al., 1998, Proc. Natl. Acad. Sci. USA 95:8910-8915; Krauss et al., 2003, Protein Engineering 16(10):753-759, all of which are incorporated herein by reference in their entireties.

[0104] II. Antibody Characteristics In some embodiments, the anti-LILRB3 antibodies described herein bind to human LILRB3. In some embodiments, the binding of the anti-LILBR3 antibodies to human LILRB3 is measured by flow cytometry, such as the exemplary assay described in Example 1.

[0105] In some embodiments, the anti-LILRB3 antibodies exhibit low immunogenicity when administered to a human subject. These antibodies may comprise an Fc domain derived from human IgG1, human IgG2, or human IgG3. In some embodiments, these antibodies are humanized using framework regions derived from human immunoglobulins.

[0106] In some embodiments, anti-LILRB3 antibodies affect T cell responsiveness. In some embodiments, anti-LILRB3 antibodies modulate surface expression of activation markers in response to different types of T cell stimulation, such as the exemplary assay described in Example 3. In some embodiments, anti-LILRB3 antibodies modulate cytokine production by PBMCs in response to T cell stimulation, such as the exemplary assay described in Example 4.

[0107] In some embodiments, the described anti-LILRB3 antibodies act as LILRB3 agonists. As a result, such anti-LILRB3 antibodies inhibit the activity of LILRB3.

[0108] In some other embodiments, the anti-LIRB3 antibodies described herein act as LILRB3 agonists. As a result, such anti-LILRB3 antibodies promote the activity of LILRB3.

[0109] The effect of anti-LILRB3 antibodies on T cell function can be assessed using various methods known in the art and described herein. Thus, anti-LILRB3 antibodies can function as LILRB3 antagonists or LILRB3 agonists.

[0110] III. Nucleic Acids of the Invention Also included in the disclosure are nucleic acids encoding the anti-LILRB3 antibodies described herein, as well as expression vectors containing such nucleic acids, and host cells transformed with such nucleic acids and / or expression vectors. As will be appreciated by those of skill in the art, the protein sequences set forth herein may be encoded by any number of possible nucleic acid sequences due to the degeneracy of the genetic code, and such nucleic acid sequences can be readily identified by one of skill in the art based on the amino acid sequences provided herein.

[0111] In some embodiments, nucleic acid compositions encoding anti-LILRB3 antibodies and / or LILRB3 binding domains are also encompassed by the present invention. As will be understood by those skilled in the art, in the case of an antigen binding domain, the nucleic acid composition generally comprises a first nucleic acid encoding a heavy chain variable region and a second nucleic acid encoding a light chain variable region. In the case of an scFv, a single nucleic acid encoding a heavy chain variable region and a light chain variable region separated by a linker as described herein can be produced. In the case of a conventional antibody, the nucleic acid composition generally comprises a first nucleic acid encoding a heavy chain and a second nucleic acid encoding a light chain, which when expressed in a cell, spontaneously assemble into a "conventional" tetrameric format consisting of two heavy chains and two light chains.

[0112] In some embodiments, the nucleic acid compositions encoding anti-LILRB3 antibodies and / or LILRB3 binding domains are codon-optimized versions or variants.

[0113] As known in the art, the nucleic acids encoding the components of the present invention can be incorporated into an expression vector and, depending on the host cell, can be used to produce the antibody of the present invention. These two nucleic acids can be incorporated into a single expression vector or into two different expression vectors. Usually, the nucleic acids are operably linked to any number of regulatory elements (promoter, origin of replication, selectable marker, ribosome binding site, inducer, etc.) in the expression vector. The expression vector can be an extrachromosomal vector or an integrating vector.

[0114] The nucleic acid and / or expression vector of the invention can be introduced into any type of host cell, including mammalian, bacterial, yeast, insect and fungal cells, as known in the art. After transfection, single cell clones can be isolated for cell bank generation using methods known in the art, such as limiting dilution, ELISA, FACS, microscopy, or Clonepix. Clones can be cultured under suitable conditions for bioreactor scale-up and sustained expression of the antibody. Antibodies can be isolated and purified using methods known in the art, including centrifugation, depth filtration, cell lysis, homogenization, freeze-thaw, affinity purification, gel filtration, ion exchange chromatography, hydrophobic interaction exchange chromatography, and mixed-mode chromatography.

[0115] IV. Therapeutic Applications The present disclosure provides a method for modulating an immune response in a subject, the method comprising administering to the subject an effective amount of an anti-LILRB3 antibody described herein, or a pharmaceutical composition comprising an anti-LILRB3 antibody.

[0116] In some embodiments, methods of modulating an immune response included in the present disclosure include inhibiting LILRB3 activity in a subject, and in further embodiments, such methods include administering to the subject an effective amount of an anti-LILRB3 antibody that acts as a LILRB3 antagonist, or administering a pharmaceutical composition comprising an antagonist anti-LILRB3 antibody. In some embodiments, methods of modulating an immune response included in the present disclosure include inhibiting LILRB3 activity in a subject, and in further embodiments, such methods include administering to the subject an effective amount of an anti-LILRB3 antibody that acts as a LILRB3 agonist, or administering a pharmaceutical composition comprising an agonist anti-LILRB3 antibody. In some embodiments, an antagonist may stimulate an immune response. In other embodiments, an antagonist may inhibit an immune response. In some embodiments, an agonist may stimulate an immune response. In other embodiments, an agonist may inhibit an immune response.

[0117] The present disclosure also provides a method of treating cancer in a subject, the method comprising administering to the subject an effective amount of an anti-LILRB3 antibody or a pharmaceutical composition comprising such an anti-LILRB3 antibody. In some embodiments, the cancer being treated expresses LILRB3 on the cancer cell surface. In some embodiments, the cancer being treated upregulates LILRB3 compared to corresponding non-cancerous tissue. In some embodiments, the subject being treated expresses LILRB3 on one or more types of immune cells, including lymphocytes, bone marrow cells, monocytes, monocyte-derived osteoclasts, granulocytes, dendritic cells, osteoclasts, and precursor mast cells. In some embodiments, the subject being treated expresses high levels of LILRB3 on one or more types of immune cells, including monocytes, monocyte-derived osteoclasts, granulocytes, dendritic cells, osteoclasts, and precursor mast cells. In some embodiments, the subject being treated expresses high levels of LILRB3 on hematopoietic cancer cells. In some embodiments, the cancer being treated is unresponsive to existing immunomodulatory antibodies that target other immune checkpoints, such as CTLA-4, PD-1, or PD-L1.

[0118] In some embodiments, the cancer is myeloid leukemia, B-lymphoid leukemia, or myeloma.

[0119] In some other embodiments, the cancer is brain cancer, bladder cancer, breast cancer, cervical cancer, endometrial cancer, esophageal cancer, leukemia, lung cancer, liver cancer, melanoma, ovarian cancer, pancreatic cancer, prostate cancer, rectal cancer, renal cancer, testicular cancer, or uterine cancer.In yet other embodiments, the cancer is angiogenic tumor, squamous cell carcinoma, adenocarcinoma, small cell carcinoma, neuroblastoma, sarcoma (e.g., angiosarcoma or chondrosarcoma), laryngeal cancer, parotid gland cancer, biliary tract cancer, thyroid cancer, acral lenticular melanoma, actinic keratosis, acute lymphocytic leukemia, acute myeloid leukemia, adenoid cystic carcinoma, adenoma, adenosarcoma, adenosquamous cell carcinoma, anal canal cancer, anal cancer, anorectal cancer, astrocytic tumor, Bartholin's gland carcinoma, basal cell carcinoma, bile duct cancer, bone cancer, bone marrow cancer, bronchial cancer, bronchial adenocarcinoma, carcinoid, cholangiocarcinoma, chondrosarcoma, choroid plexus mammary gland cancer, endothelial cell carcinoma ... Cephaloma / choroid plexus cancer, chronic lymphocytic leukemia, chronic myeloid leukemia, clear cell carcinoma, connective tissue cancer, cystadenoma, gastrointestinal cancer, duodenal cancer, endocrine system cancer, subendothelial sinus tumor, endometrial hyperplasia, endometrial stromal sarcoma, endometrioid adenocarcinoma, endothelial cell carcinoma, ependymal carcinoma, epithelial cell carcinoma, Ewing's sarcoma, eye and orbit cancer, female genital tract cancer, focal nodular hyperplasia, gallbladder cancer, gastric antrum cancer, gastric fundus cancer, gastric tumor, glioblastoma, glucagonoma, cardiac cancer, hemangioblastoma, hemangioendothelioma, hemangioma, hepatic adenoma, hepatic adenomatosis, hepatobiliary cancer, hepatocellular carcinoma, Hodgkin's disease, ileal cancer , insulinoma, intraepithelial neoplasia, interepithelial squamous cell carcinoma, intrahepatic cholangiocarcinoma, invasive squamous cell carcinoma, jejunal cancer, joint cancer, Kaposi's sarcoma, pelvic cancer, large cell carcinoma, colon cancer, leiomyosarcoma, lentigo malignant melanoma, lymphoma, male genital cancer, malignant melanoma, malignant mesothelial tumor, medulloblastoma, medulloepithelioma, meningeal cancer, mesothelial carcinoma, metastatic cancer, oral cancer, mucoepidermoid carcinoma, multiple myeloma, muscle tumor, nasal passage cancer, nervous system cancer, neuroepithelial adenocarcinoma nodular melanoma, non-epithelial skin cancer, oat cell carcinoma, oligodendroglial carcinoma, oral cancer, osteosarcoma, papillary serous adenocarcinoma, penile cancer, pharyngeal cancer, Pituitary tumor, plasmacytoma, pseudosarcoma, pulmonary blastoma, rectal cancer, renal cell carcinoma, respiratory system cancer, retinoblastoma, rhabdomyosarcoma, sarcoma, serous carcinoma, paranasal sinus cancer, skin cancer, small cell carcinoma, small intestine cancer, smooth muscle carcinoma, soft tissue cancer, somatostatin-secreting tumor, spinal cancer, squamous cell carcinoma, striatal myocarcinoma, submesothelial cancer, superficial spreading melanoma, T-cell leukemia, tongue cancer, undifferentiated carcinoma, ureteral cancer, urethral cancer, bladder cancer, urinary tract cancer, cervical cancer, uterine cancer, uveal melanoma, vaginal cancer, wart cancer, VIP-producing tumor, vulvar cancer, well-differentiated carcinoma, or Wilms' tumor.

[0120] In some other embodiments, the cancer to be treated is a non-Hodgkin's lymphoma, such as a B-cell lymphoma or a T-cell lymphoma. In certain embodiments, the non-Hodgkin's lymphoma is a B-cell lymphoma, such as diffuse large B-cell lymphoma, primary mediastinal B-cell lymphoma, follicular lymphoma, small lymphocytic lymphoma, mantle cell lymphoma, marginal zone B-cell lymphoma, extranodal marginal zone B-cell lymphoma, nodal marginal zone B-cell lymphoma, splenic marginal zone B-cell lymphoma, Burkitt's lymphoma, lymphoplasmacytic lymphoma, hairy cell leukemia, or primary central nervous system (CNS) lymphoma. In certain other embodiments, the non-Hodgkin's lymphoma is a T-cell lymphoma such as precursor T-lymphoblastic lymphoma, peripheral T-cell lymphoma, cutaneous T-cell lymphoma, angioimmunoblastic T-cell lymphoma, extranodal natural killer / T-cell lymphoma, enteropathy-type T-cell lymphoma, subcutaneous panniculitis-like T-cell lymphoma, anaplastic large cell lymphoma, or peripheral T-cell lymphoma.

[0121] The present disclosure also provides a method of treating an autoimmune or inflammatory disorder in a subject, the method comprising administering to the subject an effective amount of an anti-LILRB3 antibody that acts as a modulator of LILRB3. In some embodiments, the subject being treated expresses LILRB3 on one or more types of immune cells, including lymphocytes, bone marrow cells, monocytes, monocyte-derived osteoclasts, granulocytes, dendritic cells, osteoclasts, and precursor mast cells. In some embodiments, the subject being treated expresses high levels of LILRB3 on one or more types of immune cells, including lymphocytes, bone marrow cells, monocytes, monocyte-derived osteoclasts, granulocytes, dendritic cells, osteoclasts, and precursor mast cells. In some embodiments, LILRB3 is expressed at high levels in autoreactive immune cells (e.g., T cells, B cells, natural killer cells, dendritic cells, endothelial cells, and macrophages at sites where autoimmune disease develops, such as, for example, lymph nodes and the central nervous system of subjects with multiple sclerosis, joints of subjects with rheumatoid arthritis, and the gastrointestinal tract of subjects with celiac disease) in a subject. LILRB3 activity can be inhibited by administering an anti-LILRB3 antibody that acts as a LILRB3 antagonist. LILRB3 activity can be promoted by administering an anti-LILRB3 antibody that acts as a LILRB3 agonist.

[0122] In some embodiments, the autoimmune or inflammatory disorder being treated is asthma, multiple sclerosis, Addison's disease, amyotrophic lateral sclerosis, Crohn's disease, Cushing's syndrome, diabetes mellitus type 1, graft versus host disease, Graves' disease, Guillain-Barre syndrome, lupus erythematosus, psoriasis, psoriatic arthritis, rheumatoid arthritis, sarcoidosis, scleroderma, systemic lupus erythematosus, transplant rejection, or vasculitis.

[0123] In some other embodiments, the autoimmune disorder to be treated includes acute disseminated encephalomyelitis (ADEM), agammaglobulinemia, alopecia areata, ankylosing spondylitis, antiphospholipid syndrome, antisynthetase syndrome, atopic allergy, atopic dermatitis, autoimmune aplastic anemia, autoimmune cardiomyopathy, autoimmune enteropathy, autoimmune hemolytic anemia, autoimmune hepatitis, autoimmune inner ear disease, autoimmune lymphoproliferative syndrome, autoimmune pancreatitis, autoimmune peripheral neuropathy, autoimmune pancreatitis polyendocrine syndrome, autoimmune progesterone-induced dermatitis, autoimmune rheumatoid arthritis ... Thrombocytopenic purpura, autoimmune urticaria, autoimmune uveitis, Baro's disease / Baroconcentric sclerosis, Behcet's disease, Burger's disease, Bickerstaff encephalitis, Blau syndrome, bullous pemphigoid, cancer, Castleman's disease, celiac disease, Chagas disease, chronic inflammatory demyelinating polyneuropathy, chronic inflammatory demyelinating polyneuropathy, chronic obstructive pulmonary disease, chronic relapsing multifocal osteomyelitis, Churg-Strauss syndrome, cicatricial pemphigoid, Cogan's syndrome, cold agglutinin disease, complement component 2 deficiency, contact dermatitis, cranial arteritis, CREST syndrome, cutaneous leukocytoclastic vascular inflammatory bowel disease, Dego's disease, Dercum's disease, herpetic dermatitis, dermatomyositis, diffuse cutaneous systemic sclerosis, discoid erythematous pneumonia, Dressler's syndrome, drug-induced eosinophilic fasciitis, eczema, endometriosis, eosinophilic fasciitis, eosinophilic gastroenteritis, eosinophilic pneumonia, epidermolysis bullosa, erythema nodosum, erythroblastosis fetalis, essential mixed cryoglobulinemia, Evan's syndrome, fibrodysplasia gestationis, fibrous alveolitis (or idiopathic pulmonary fibrosis), gastritis, gastrointestinal pemphigoid, glomerulonephritis, Goodpasture's syndrome, Hashimoto's encephalopathy, Hashimoto's thyroiditis, Henoch-Schönlein purpura, gestational pemphigoid Pemphigus (aka gestational pemphigoid), hidradenitis suppurativa, Hughes-Stobin syndrome, hypogammaglobulinemia, idiopathic inflammatory demyelinating disease, idiopathic pulmonary fibrosis, idiopathic pulmonary fibrosis thrombocytopenic purpura, IgA nephropathy, inclusion body myositis, interstitial cystitis, juvenile idiopathic arthritis (aka juvenile rheumatoid arthritis), Kawasaki disease, Lambert-Eaton myasthenic syndrome, leukocytoclastic vasculitis, lichen planus, lichen sclerosus, linear IgA disease, lupoid hepatitis (aka autoimmune hepatitis), Majeed syndrome, microscopic colitis, microscopic polyangiitis, Miller-Fisher syndrome, mixed connective tissue disease, morphea,Mucha-Habermann disease (also known as Pityriasis lichenoides and Varioliformis acta), multiple sclerosis, Miasthenia gravis, myositis, Meniere's disease, paralysis, neuromyelitis optica, neuromyotonia, neuromyositis ocular cicatricial variola, opsoclonus-myoclonus syndrome, Ord's thyroiditis, palindromic rheumatism, PANDAS (pediatric autoimmune neuropsychiatric disorders associated with streptococci), paraneoplastic cerebellar degeneration, paroxysmal nocturnal hemoglobinuria (PNH), Parry-Romberg syndrome, pars planitis, Parsonage-Turner syndrome, pemphigus vulgaris, perivenous encephalomyelitis, pernicious anemia, POEMS syndrome, polyarteritis nodosa, polymyalgia rheumatica, polymyositis, primary biliary hepatitis These include, but are not limited to, cirrhosis, primary sclerosing cholangitis, progressive inflammatory neuropathy, pure red cell aplasia, pyoderma gangrenosum, Rasmussen's encephalitis, Raynaud's syndrome, Reiter's syndrome, relapsing polychondritis, restless legs syndrome, retroperitoneal fibrosis, rheumatic fever, schizophrenia, Schmidt's syndrome, Schnitzler's syndrome, scleritis, serum sickness, Sjogren's syndrome, spondyloarthropathy, stiff person syndrome, Still's disease, subacute bacterial endocarditis (SBE), Susac syndrome, Sweet's syndrome, Sydenham's chorea, sympathetic ophthalmia, Takayasu's arteritis, temporal arteritis, thrombocytopenia, Tolosa Hunt syndrome, transverse myelitis, ulcerative colitis, undifferentiated spondyloarthropathy, urticarial vasculitis, vitiligo, and Wegener's granulomatosis.

[0124] The present disclosure also provides a method of treating allergic inflammation in a subject, the method comprising administering to the subject an effective amount of any one of the anti-LILRB3 antibodies described herein, or any one of the compositions described herein.

[0125] In some embodiments, the allergic inflammation to be treated may be associated with allergic asthma, atopic dermatitis, allergic rhinitis, allergic conjunctivitis.

[0126] The present disclosure also provides a method of modulating osteoclast differentiation, the method comprising administering to a subject an effective amount of any one of the anti-LILRB3 antibodies described herein, or any one of the compositions described herein. In some embodiments, modulation of osteoclast differentiation may be particularly useful in treating bone loss or bone resorption in patients suffering from or susceptible to a condition selected from the group consisting of osteoporosis, osteodystrophy, osteopenia, osteomalacia, hyperparathyroidism, hyperthyroidism, hypogonadism, thyrotoxicosis, systemic mastocytosis, adult hypophosphatasia, hyperadrenocorticism, osteoporosis, Paget's disease, Cushing's disease / syndrome, Tumer's syndrome, Gaucher's disease, Ehlers-Danlos syndrome, Marfan syndrome, Menkes syndrome, Fanconi syndrome, multiple myeloma, hypercalcemia, hypocalcemia, arthritis, periodontal disease, ricketts (including vitamin D-dependent, types I and II, and x-linked hypophosphatemic ricketts), or other forms of vitamin D deficiency, such as vitamin D deficiency associated with chronic kidney disease or renal failure, bone sclerotic disorders such as fibrodysplastic bone, pyknotic dysostosis, and damage resulting from macrophage-mediated inflammatory processes.

[0127] V. Combination Therapy The anti-LILRB3 antibodies described herein can be used in combination with additional therapeutic agents to treat cancer, autoimmune disorders, and allergic inflammation. The anti-LILRB3 antibodies can also be used in combination with additional therapeutic agents to regulate osteoclast differentiation.

[0128] Exemplary therapeutic agents that can be used as part of a combination therapy in the treatment of cancer include, for example, radiation, mitomycin, tretinoin, ribomustine, gemcitabine, vincristine, etoposide, cladribine, mitobronitol, methotrexate, doxorubicin, carboquone, pentostatin, nitracrine, zinostatin, cetrorelix, letrozole, raltitrexed, daunorubicin, fadrozole, fotemustine, thymalfasin, sobuzoxane, nedaplatin, cytarabine, bicalutamide, vinorelbine, vesnarinone, aminoglutethimide, amsacrine, proglumide, elliptinium acetate, ketanserin, doxifluridine, etretinate, isotretinoin, streptozocin, nimustine, vindesine, furuta, These include: cyclosporine, ...

[0129] An additional class of agents that can be used as part of a combination therapy in the treatment of cancer are immune checkpoint inhibitors. Exemplary immune checkpoint inhibitors include agents that inhibit one or more of: (i) cytotoxic T-lymphocyte-associated antigen 4 (CTLA4), (ii) programmed cell death protein 1 (PD1), (iii) PDL1, (iv) LAG3, (v) B7-H3, (vi) B7-H4, and (vii) TIM3 (e.g., ipilimumab, nivolumab, pembrolizumab, avelumab, durvalumab, atezolizumab, etc.).

[0130] Still other agents that may be used as part of a combination therapy in the treatment of cancer are monoclonal antibody agents that target non-checkpoint targets (e.g., Herceptin) and non-cytotoxic agents (e.g., tyrosine kinase inhibitors).

[0131] Further categories of anti-cancer drugs include, for example, (i) ALK inhibitors, ATR inhibitors, A2A antagonists, base excision repair inhibitors, Bcr-Abl tyrosine kinase inhibitors, Bruton's tyrosine kinase inhibitors, CDC7 inhibitors, CHK1 inhibitors, cyclin-dependent kinase inhibitors, DNA-PK inhibitors, inhibitors of both DNA-PK and mTOR, DNMT1 inhibitors, DNMT1 inhibitors and 2-chlorodeoxyadenosine, HDAC inhibitors, hedgehog signaling pathway inhibitors, IDO inhibitors, JAK inhibitors, mTOR inhibitors, MEK inhibitors, The antibodies of the present invention may be used to treat cancer. ...

[0132] Exemplary therapeutic agents that can be used as part of a combination therapy with an anti-LILRB3 antibody to treat, slow the progression of, prevent the recurrence of, or alleviate the symptoms of an autoimmune or inflammatory disorder include, for example, various known anti-inflammatory and / or immunosuppressive therapies. In some embodiments, anti-inflammatory and / or immunosuppressive therapies include, but are not limited to, methotrexate, cyclosporine A (including, for example, cyclosporine microemulsion), tacrolimus, corticosteroids, statins, interferon beta, nonsteroidal anti-inflammatory agents, and 6-MP (mercaptopurine, also known as 6-mercaptopurine, or purinetol).

[0133] In some embodiments, anti-inflammatory and / or immunosuppressive therapies for combination with anti-LILRB3 antibodies include TOPK inhibitors (e.g., OTS964 ((R)-9-(4-(1-(dimethylamino)propan-2-yl)phenyl)-8-hydroxy-6-methylthieno[2,3-c]quinolin-4(5H)-one) (Oncology Therapeutics Sciences)), tyrosine kinase inhibitors (e.g., axitinib, dasatinib, icotinib), topoisomerase inhibitors (e.g., topotecan), sphingosine-1-phosphate receptor agonists (e.g., fingolimod, KRP-203), anti-T cell immunoglobulins (e.g., AtGam), anti-IL-2 receptor antibodies (e.g., daclizumab), amide (CTX), ifosphatase inhibitors (e.g., cyclosporine, cyclosporine), cyclosporine inhibitors (e.g. ... These include, but are not limited to, rifabutinib (IFO), adriamycin (ADM), daunorubicin (DNR), vincristine (VCR), vinblastine (VBL), etoposide (VP16), Vermeer (Vumon), carboplatin (CBP), tacrolimus, sirolimus, everolimus, azathioprine, brequinar, leflunomide, LEA-29Y, anti-CD3 antibodies (e.g., OKT3), aspirin, B7-CD28 blocking molecules (e.g., belatacept, abatacept), CD40-CD154 blocking molecules (anti-CD40 antibodies), acetaminophen, ibuprofen, naproxen, pyroxicam, and anti-inflammatory steroids (e.g., prednisolone or dexamethasone).

[0134] In some embodiments, anti-inflammatory and / or immunosuppressive therapies for combination with anti-LILRB3 antibodies include, for example, elimination of autoimmune cells by administration of TNF-alpha, CFA, interleukin-1 (IL-1), proteasome inhibitors, NFκB inhibitors, anti-inflammatory drugs, tissue plasminogen activator (TPA), lipopolysaccharide, UV light, and intracellular mediators of the TNF-alpha signaling pathway. Such agents induce apoptosis of autoreactive lymphocytes by blocking pathways downstream of TNF-alpha receptor signaling or act downstream of TNF-alpha receptor binding. (Baldwin et al., Ann. Rev. Immunol. (1996) 12:141; Baltimore, Cell (1996) 87:13).

[0135] In some embodiments, anti-LILRB3 antibodies are used in conjunction with surgical procedures to treat or otherwise alleviate autoimmune diseases.

[0136] Exemplary therapeutic agents that can be used as part of a combination therapy with an anti-LILRB3 antibody to treat or slow the progression of or prevent or alleviate the symptoms of allergic inflammation include, for example, any of a variety of known anti-inflammatory and / or immunosuppressive therapies. In some embodiments, anti-inflammatory and / or immunosuppressive therapies for combination with an anti-LILRB3 antibody include short-acting beta 2 agonists, long-acting beta 2 agonists, anticholinergics, corticosteroids, systemic corticosteroids, mast cell stabilizers, leukotriene modifiers, methylxanthines, beta 2 agonists, albuterol, levalbuterol, pirbuterol, altoformoterol, formoterol, salmeterol, anticholinergics (including ipratropium and tiotropium), corticosteroids (including beclomethasone, budesonide, flunisolide, fluticasone, mometasone, triamcinolone, methylprednisolone, prednisolone, methylpre ... These include, but are not limited to, benzodiazepines, benzodiazepines, and benzocaline; leukotriene modifiers (including montelukast, zafirlukast, and zileuton); mast cell stabilizers (including cromolyn and nedocromil); methylxanthines (including theophylline); combination medications (including ipratropium and albuterol, fluticasone and salmeterol, budesonide and formoterol); antihistamines (including hydroxyzine, diphenhydramine, loratadine, cetirizine, and hydrocortisone); immune system modifiers (including tacrolimus and pimecrolimus), cyclosporine, azathioprine, mycophenolate mofetil, and combinations thereof.

[0137] In other embodiments, therapeutic agents that may be used as part of a combination therapy with an anti-LILRB3 antibody to treat, slow the progression of, or prevent the recurrence of, or alleviate the symptoms of allergic inflammation may also include those therapeutic agents designated for autoimmune or inflammatory diseases.

[0138] Exemplary therapeutic agents that may be used as part of a combination therapy with an anti-LILRB3 antibody to modulate osteoclast activity include, but are not limited to, bisphosphonates, calcitonin, estrogen replacement, sclerostin antibodies, RANKL antibodies, parathyroid peptides, strontium ranelate, TNFα inhibitors, colony stimulating factor 1 inhibitors, colony stimulating factor 1 receptor inhibitors, cathepsin K inhibitors, V-ATPase inhibitors, and glucagon-like peptide 2.

[0139] The amounts of antibody and additional therapeutic agent, as well as the relative timing of administration, can be selected to achieve a desired combined therapeutic effect. For example, when administering combination therapy to a patient in need of such administration, the combined therapeutic agent, or pharmaceutical composition(s) comprising the therapeutic agents, can be administered in any order, e.g., sequentially, in parallel, together, simultaneously, etc. Furthermore, for example, the multispecific binding protein can be administered during the period during which the additional therapeutic agent exerts its prophylactic or therapeutic effect, or vice versa.

[0140] VI. Pharmaceutical Compositions and Administration The present disclosure also features pharmaceutical compositions / formulations comprising a therapeutically effective amount of the anti-LILRB3 antibody described herein. The compositions can be formulated for use in various drug delivery systems. One or more physiologically acceptable excipients or carriers may also be included in the compositions for proper formulation. Formulations suitable for use in the present disclosure can be found in Remington's Pharmaceutical Sciences, Mack Publishing Company, Philadelphia, Pa., 17th ed., 1985. For a brief review of methods of drug delivery, see, for example, Langer (Science 249:1527-1533, 1990).

[0141] The antibody of the present disclosure can be present in a lyophilized formulation or a liquid aqueous pharmaceutical formulation. The aqueous carriers of interest herein are those that are pharma- ceutically acceptable (safe and non-toxic for administration to humans) and useful for preparing liquid formulations. Exemplary carriers include sterile water for injection (SWFI), bacteriostatic water for injection (BWFI), pH buffer (e.g., phosphate buffered saline), sterile saline, Ringer's solution, or dextrose solution.

[0142] The antibody of the present disclosure may be present in a lyophilized formulation comprising a protein and a cryoprotectant. The cryoprotectant may be a sugar, for example, a disaccharide. In certain embodiments, the cryoprotectant is sucrose or maltose. The lyophilized formulation may also comprise one or more of a buffer, a surfactant, a bulking agent, and / or a preservative.

[0143] The actual dosage level of the active ingredient in the pharmaceutical composition of the present invention can be varied for a particular patient, a particular composition, and a particular mode of administration, so as to provide an amount of the active ingredient that is not toxic to the patient and is effective to achieve the desired therapeutic response. For adults, active antibody can be administered in the range of 0.1 mg to 1 g, preferably 0.5 mg to 500 mg per administration. Alternatively, the patient's dose can be adjusted to the approximate weight or body surface area of ​​the patient. Other factors in determining the appropriate dosage can include the disease or condition being treated or prevented, the severity of the disease, the route of administration, and the age, sex, and medical condition of the patient. Further refinement of the calculations required to determine the appropriate dosage for treatment is routinely performed by those skilled in the art, especially in light of the dosage information and assays disclosed herein. Dosages can also be determined by using known assays for determining dosages used in conjunction with appropriate dose-response data. Dosages for individual patients can be adjusted while monitoring the progression of the disease. By measuring the blood levels of the targetable construct or complex in the patient, it can be ascertained whether the dosage needs to be adjusted to reach or maintain an effective concentration. Pharmacogenomics can be used to determine which targetable constructs and / or complexes, and their dosages, are likely to be most effective for a given individual (Schmitz et al., Clinica Chimica Acta 308:43-53, 2001; Steimer et al., Clinica Chimica Acta 308:33-41, 2001).

[0144] Doses can be given one or more times daily, weekly, monthly or yearly, or even once every 2-20 years. One of skill in the art can easily estimate dosing repetition rates based on measured residence times and concentrations of the targetable construct or complex in bodily fluids or tissues. Administration of the present invention can be intravenous, intraarterial, intraperitoneal, intramuscular, subcutaneous, intrapleural, intrathecal, intracavity, perfusion via catheter, or direct intralesional injection. It can be administered one or more times daily, one or more times weekly, one or more times monthly, and one or more times yearly.

[0145] Working Example The invention outlined herein will be more readily understood by reference to the following examples, which are included solely for the purpose of illustrating certain aspects and embodiments of the invention and are not intended to be limiting of the invention.

[0146] Example 1 - LILRB3 surface expression on hematopoietic cell subsets Surface expression of LILRB3 was measured in various hematopoietic subsets in the form of two-dimensional flow cytometry (FCM) representations called quantile contour plots (probability plots). Peripheral blood mononuclear cells (PBMCs) from healthy human donors were stained with LILRB3 3A3 antibody and antibodies specific for the indicated cell subsets. The plots in Figure 1A show LILRB3 expression by gated CD3+CD4+T cells, CD3+CD8+T cells, or CD11b+monocytes. In Figure 1B, fresh whole blood from a healthy human donor was stained as in Figure 1A. The plots show LILRB3 expression by gated CD3+CD4+T cells, CD3+CD8+T cells, CD11b+monocytes, or CD11b+granulocytes. The percentages of gated cells and LILRB3+ cells within the gated populations are shown within the plots (first and second numbers, respectively). Expression of LILRB3 was shown in monocytes and granulocytes, and low expression of LILRB3 was shown in CD4+ or CD8+ T cells. The specificity of LILRB3 staining was determined by staining all above mentioned cell subsets with IgG1 isotype control antibody. Data are representative of several independent experiments utilizing various human blood samples.

[0147] Example 2 - Effect of LILRB3 antibody or LILRB3-Fc protein on T cell responsiveness in primary mixed lymphocyte reaction (MLR) CD3+ T cells [1×10 5 cells, effector (E) population] and irradiated (IR) allogeneic CD14+ monocytes from healthy human donors [2 × 10 5Cells, stimulator (S) population] were co-cultured in the presence or absence of the indicated amounts of IgG1 or IgG2b isotype control antibody, LILRB3 antibody, Fc protein, or Fc-LILRB3 protein. After 3 days, cells were labeled with 3H-thymidine and T cell proliferation was measured for an additional 18 hours. LILRB3 7C5 antibody and LILRB3 Fc protein inhibited T cell proliferation (Figure 2). Data shown are representative of several independent experiments utilizing different effector / stimulator pairs and are reported as mean counts per minute (cpm) ± standard error of triplicate wells.

[0148] Example 3 - PBMCs incubated with LILRB3 7C5 antibody fail to fully modulate surface expression of activation markers in response to T cell stimulation PBMCs (2x10) from healthy human donors 5 LILRB3 7C5 antibody inhibits activation of CD4+ and CD8+ T cells by anti-CD3 and anti-CD28 antibodies, as shown by the decreased expression of CD69 (type II C-lectin receptor) and CD25 (IL-2 receptor), and the decreased shedding of CD62L (L-selectin). Data are representative of several independent experiments utilizing different human PBMC samples and are reported as mean fluorescence intensity (MFI) ± standard error of triplicate wells.

[0149] Example 4 - LILRB3 antibodies alter cytokine production by PBMCs in response to T cell stimulation. PBMCs (2x10) from healthy human donors 5Cells) were cultured in the presence or absence of 7C5 or isotype control antibody (20 μg / mL), as well as anti-CD3 (1 ng / mL) and anti-CD28 (100 ng / mL) antibodies. After 24 h, cytokine levels in the culture supernatants were determined by BioLegend LEGENDplex Human Th CytokinePanel according to the manufacturer's instructions. In the presence of 7C5, the levels of certain cytokines, including IL-2, IL-4, IL-5, IL-13, IL-17, and IFNγ, were decreased, whereas the levels of IL-6, IL-10, and TNF were increased (Figure 4). Data are representative of several independent experiments utilizing different human PBMC samples and are reported as fold change for 7C5 compared to isotype control antibody in duplicate wells.

[0150] Example 5 - LILRB3 7C5 antibody does not induce significant release of cytokines from unstimulated whole blood. Fresh blood from healthy human donors (n=4) was diluted 4:1 in RPMI1640 medium and incubated for 4 h in the presence of 7C5 antibody or isotype control antibody (50 μg / mL). LPS (1 μg / mL) was used as a positive control. Cytokine levels in serum samples were determined by BioLegend LEGENDplex Human Th CytokinePanel according to the manufacturer's instructions. LILRB3 7C5 antibody did not show a significant stimulatory effect in the absence of T cell receptor stimulation (Figure 5). Data are representative of several independent experiments and are reported as the average fold change for 7C5 compared to isotype control antibody in duplicate wells.

[0151] Incorporation by Reference The entire disclosure of each patent document and scientific article referenced herein is incorporated by reference for all purposes.

[0152] Equivalent The present disclosure may be embodied in other specific forms without departing from its spirit or essential characteristics. The foregoing embodiments are therefore to be considered in all respects as illustrative and not limiting of the invention described herein. The scope of the present disclosure is therefore indicated by the appended claims rather than the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

1. An antibody that binds to human LILRB3, vhCDR1 comprising SEQ ID NO:51, vhCDR2 comprising SEQ ID NO:52, vhCDR3 comprising SEQ ID NO:53, vlCDR1 comprising SEQ ID NO:54, vlCDR2 comprising SEQ ID NO:55, and An antibody comprising a vlCDR3 comprising sequence number 56.

2. A heavy chain variable region of the amino acid sequence DVQLLETGGGLVQPGGSRGLSCEGSGFTFSGFWMSWVRQTPGKTLEWIGDINSDGTAINYAPSIKDRFTIFRDNDKSTLYLQMSNVRSEDTATYFCMRSYGSGPWCFDVWGTGTTVTVS contained in SEQ ID NO:9; and a light chain variable region of the amino acid sequence QIVLTQSPAIMSASLGERVTMTCTASSSVSSAYLHWYQQKPGSSPKLWIYSTSNLASGVPTRFSGSGSGTSYSLTISSMEAEDAATYYCHQYHRSPFTFGAGTKLELK contained in SEQ ID NO: 10; The antibody that binds to human LILRB3 of claim 1 .

3. The antibody of claim 1 or 2, wherein the antibody comprises a constant region having an amino acid sequence that is at least 90% identical to human IgG.

4. The antibody of claim 3 , wherein the human IgG is selected from the group consisting of IgG1, IgG2, IgG3 and IgG4.

5. The antibody of claim 4, wherein the IgG is IgG1.

6. The antibody of claim 4, wherein the IgG is IgG2.

7. A nucleic acid composition encoding the antibody of any one of claims 1 to 6.

8. 8. An expression vector composition comprising the nucleic acid composition of claim 7, wherein the first nucleic acid is contained in a first expression vector and the second nucleic acid is contained in a second expression vector.

9. 8. An expression vector composition comprising the nucleic acid composition of claim 7, wherein the first nucleic acid and the second nucleic acid are contained in a single expression vector.

10. A host cell comprising the expression vector composition of claim 8 or 9.

11. 11. A method of producing an antibody comprising culturing the host cell of claim 10 under conditions in which the antibody is expressed, and recovering the antibody.

12. A composition comprising an antibody according to any one of claims 1 to 6 and a pharma- ceutically acceptable carrier or diluent.

13. A pharmaceutical composition for modulating an immune response in a subject, comprising an effective amount of an antibody according to any one of claims 1 to 6, or a composition according to claim 12.

14. A pharmaceutical composition for treating cancer in a subject, comprising an effective amount of an antibody according to any one of claims 1 to 6, or a composition according to claim 12.

15. The pharmaceutical composition of claim 14, wherein the cancer upregulates LILRB3.

16. The pharmaceutical composition of claim 14 or 15, wherein the subject has high levels of LILRB3 on hematopoietic cancer cells.

17. The pharmaceutical composition according to any one of claims 14 to 16, wherein the cancer is leukemia.

18. The pharmaceutical composition according to any one of claims 14 to 16, wherein the cancer is myeloma.

19. The pharmaceutical composition of any one of claims 14 to 18, wherein the antibody or composition is combined with one or more additional therapeutic agents for treating cancer.

20. 20. The pharmaceutical composition of claim 19, wherein the additional therapeutic agent is another immune checkpoint inhibitor.

21. 21. The pharmaceutical composition of claim 20, wherein the other immune checkpoint inhibitor is selected from the group consisting of ipilimumab, nivolumab, pembrolizumab, avelumab, durvalumab, and atezolizumab.

22. A pharmaceutical composition for treating an autoimmune disease in a subject, comprising an effective amount of an antibody according to any one of claims 1 to 6, or a composition according to claim 12.

23. 23. The pharmaceutical composition of claim 22, wherein the antibody or composition is combined with one or more additional therapeutic agents to treat an autoimmune disease.

24. A pharmaceutical composition for treating allergic inflammation in a subject, comprising an effective amount of an antibody according to any one of claims 1 to 6, or a composition according to claim 12.

25. 25. The pharmaceutical composition of claim 24, wherein the antibody or composition is combined with one or more additional therapeutic agents to treat allergic inflammation.

26. A pharmaceutical composition for regulating osteoclast differentiation in a subject, comprising an effective amount of the antibody according to any one of claims 1 to 6, or the composition according to claim 12.

27. 27. The pharmaceutical composition of claim 26, wherein the antibody or composition is combined with one or more additional therapeutic agents to modulate osteoclast differentiation.

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