KIR binding antibodies and antigen binding fragments thereof

Abstract

The technology relates in part to antibodies or antigen-binding fragments thereof that bind one or more members of the KIR family of proteins (e.g., KIR2DL1, KIR2DL2, KIR2DL3, KIR2DL4, KIR2DL5, KIR2DS1, KIR2DS2, KIR2DS4, KIR2DS5, KIR3DL1, KIR3DL2, and / or KIR3DL3) or portions thereof, as well as methods, systems and kits for detection of KIR. In certain aspects, the technology relates to antibodies or antigen binding fragments thereof for use in determining levels of KIR in a sample containing or suspected of containing KIR. In some aspects, the technology relates to antibodies or antigen-binding fragments thereof for use in diagnosing or treating an individual with or suspected of having a disease or disorder associated with KIR.

Description

[0001] KIR BINDING ANTIBODIES AND ANTIGEN BINDING FRAGMENTS THEREOF

[0002] Related patent applications

[0003] This patent application claims the benefit of U.S. provisional patent application no. 63 / 640,988 filed on May 1 , 2024, entitled KIR BINDING ANTIBODIES AND ANTIGEN BINDING FRAGMENTS THEREOF, naming Evan TENG et al. as inventors, and designated by attorney docket no. BIOLEG-1002PROV. The entire content of the foregoing patent application is incorporated herein by reference for all purposes, including all text, tables and drawings.

[0004] Field

[0005] The technology relates in part to antibodies or antigen-binding fragments thereof that bind one or more members of the KIR family of proteins (e.g., KIR2DL1 , KIR2DL2, KIR2DL3, KIR2DL4, KIR2DL5, KIR2DS1 , KIR2DS2, KIR2DS4, KIR2DS5, KIR3DL1 , KIR3DL2, and / or KIR3DL3) or portions thereof, as well as methods, systems and kits for detection of KIR. In certain aspects, the technology relates to antibodies or antigen binding fragments thereof for use in determining levels of KIR in a sample containing or suspected of containing KIR. In some aspects, the technology relates to antibodies or antigen-binding fragments thereof for use in diagnosing or treating an individual with or suspected of having a disease or disorder associated with KIR.

[0006] Background

[0007] Killer Cell Immunoglobulin-like Receptors (KIR) are a family of receptors expressed by natural killer cells and T lymphocytes. The KIR family of proteins are transmembrane glycoproteins and part of the immunoglobulin superfamily. KIR proteins include an extracellular structure and an intracellular structure. Extracellular KIR domains may be characterized as immunoglobulin-like domains. Intracellular domains contain ITAM (activating) and / or ITIM (inhibitory) regions depending on the variant. KIR proteins range in size from about 30 kDa to about 50 kDa. Some KIR proteins interact with MHC Class 1 molecules (HLA) on a target cell to prevent cell killing and lysis of the target cell by NK cells while other KIR proteins react to HLAs to cause activation or inhibition in NK cells (Pende, D. et al. Front Immunol, (2019), Debska-Zielkowska, J. et al. Cells (2021 )).

[0008] High homology exists among KIR receptors. Accordingly, antibodies specifically recognizing certain members of the KIR family have not been developed. In order to generate antibodies targeting certain members of the KIR family specifically, a collection of monoclonal antibodies was generated against certain KIR receptor family members, including KIR2DL1 , KIR2DL2, KIR2DL3, KIR2DL4, KIR2DL5, KIR2DS1 , KIR2DS2, KIR2DS4, KIR2DS5, KIR3DL1 , KIR3DL2, and KIR3DL3, for example. The specificity of these antibodies was verified using engineered cell lines and human peripheral blood samples. For example, a KIR2DS1 -specific monoclonal antibody described herein can distinguish between the closely related KIR2DL1 versus KIR2DS1 proteins; KIR2DL5-specific monoclonal antibodies described herein can better target broader KIR2DL5 variants compared to current commercially available clones. In addition to those single specific KIR antibodies, multiple clones are able to determine shared epitopes of two or more KIRs including KIR2DL2, KIR2DL3, and KIR2DS2. Such monoclonal antibodies may have applications in immunophenotyping, diagnostics, and therapeutics, for example.

[0009] Summary

[0010] Provided in certain aspects are antibodies or antigen binding fragments thereof that bind one or more killer cell immunoglobulin-like receptors (KIRs) or a portion thereof, comprising (a) an immunoglobulin heavy chain variable domain comprising (i) a heavy chain complementarity determining region 1 (CDRH1 ) comprising a CDRH1 polypeptide provided in Table 3, or a polypeptide that is at least 80 percent identical to a CDRH1 polypeptide provided in Table 3; (ii) a heavy chain complementarity determining region 2 (CDRH2) comprising a CDRH2 polypeptide provided in Table 3, or a polypeptide that is at least 80 percent identical to a CDRH2 polypeptide provided in Table 3; and (iii) a heavy chain complementarity determining region 3 (CDRH3) comprising a CDRH3 polypeptide provided in Table 3, or a polypeptide that is at least 80 percent identical to a CDRH3 polypeptide provided in Table 3; and (b) an immunoglobulin light chain variable domain comprising (i) a light chain complementarity determining region 1 (CDRL1 ) comprising a CDRL1 polypeptide provided in Table 3, or a polypeptide that is at least 80 percent identical to a CDRL1 polypeptide provided in Table 3; (ii) a light chain complementarity determining region 2 (CDRL2) comprising a CDRL2 polypeptide provided in Table 3, or a polypeptide that is at least 80 percent identical to a CDRL2 polypeptide provided in Table 3; and (iii) a light chain complementarity determining region 3 (CDRL3) comprising a CDRL3 polypeptide provided in Table 3, or a polypeptide that is at least 80 percent identical to a CDRL3 polypeptide provided in Table 3.

[0011] Also provided in certain aspects are isolated antibodies or antigen binding fragments thereof that bind one or more killer cell immunoglobulin-like receptors (KIRs) or a portion thereof, where the antibody or antigen binding fragment thereof blocks or is capable of blocking KIR ligand binding.

[0012] Also provided in certain aspects are isolated antibodies or antigen binding fragments thereof that bind one or more killer cell immunoglobulin-like receptors (KIRs) or a portion thereof, where the antibody or antigen binding fragment thereof enhances or is capable of enhancing KIR ligand binding.

[0013] Also provided in certain aspects are isolated antibodies or antigen binding fragments thereof that bind one or more killer cell immunoglobulin-like receptors (KIRs) or a portion thereof, where the antibody or antigen binding fragment thereof inhibits or is capable of inhibiting natural killer cell activity.

[0014] Also provided in certain aspects are isolated antibodies or antigen binding fragments thereof that bind one or more killer cell immunoglobulin-like receptors (KIRs) or a portion thereof, where the antibody or antigen binding fragment thereof activates or is capable of activating natural killer cell activity.

[0015] Also provided in certain aspects are isolated antibodies or antigen binding fragments thereof that bind one or more killer cell immunoglobulin-like receptor (KIR) protein family members or a portion or portions thereof, where the antibody comprises: (i) an immunoglobulin heavy chain comprising a set of heavy chain complementarity determining region (CDR) amino acid sequences, CDRH1 ,

[0016] CDRH2, and CDRH3; and, (ii) an immunoglobulin light chain comprising a set of light chain CDR amino acid sequences, CDRL1 , CDRL2, and CDRL3, wherein the sets of heavy chain and light chain CDRs are each chosen from the same of set A, B, C, D, E, F, G, H, I, J, K, or L:

[0017] Certain implementations are described further in the following description, examples and claims, and in the drawings.

[0018] Brief Description of the Drawings

[0019] The drawings illustrate certain implementations of the technology and are not limiting. For clarity and ease of illustration, the drawings are not made to scale and, in some instances, various aspects may be shown exaggerated or enlarged to facilitate an understanding of particular implementations.

[0020] Fig. 1 shows a screening matrix of potential KIR2DL4 staining clones using transfected cell line Ba / F3. Positives are noted as ‘Y’ and negatives are noted as N’. This matrix shows specificity for a particular KIR, in this case KIR2DL4 for S23004D, S22010B, S22010H, and mAb-33.

[0021] Fig. 2 shows histograms of clones tested for two positive cell lines (KIR2DL4-55 and KIR2DL4-71 transfected Ba / F3) which the clones show positivity for KIR2DL4.

[0022] Fig. 3 shows titration data from 2 pg to 0.0625 pg for each clone on two KIR2DL4 (2DL4-55 and 2DL4-71 ) cell lines showing high mean fluorescence signals at each concentration. S23004D is highest shown here.

[0023] Fig. 4 shows KIR2DL4 antibody crossblocking. Specifically, shown here is results of an epitope interaction assay where one antibody is used to block another to create the matrix. No changes from blocking are ‘signal’, loss of signal is ‘block’, and partial decreases are ‘partial’. Some interactions have increases in signal designated ‘higher’. This shows S23004D has a different epitope than the others and / or has much stronger binding. Fig. 5 shows primary peripheral blood lymphocyte staining using CD56 (NK marker) and KIR2DL4 testing antibodies. The positive population in this case is the CD56 high and Y axis positive population, showing positive primary cell population identification.

[0024] Fig. 6 shows KIR2DL4 expression in a population of IL-2 stimulated PBMCs. For KIR2DL4, stimulation may show a larger population of positives. The comparison stain shows S23004D can identify the population better than other clones.

[0025] Fig. 7 shows interactions of test clones and reference clones with KIR2DL4 recombinant protein. In particular, this figure shows recombinant protein neutralization of the test clones which show reduced staining when blocked by recombinant protein KIR2DL4. This indicates the antibodies are specific to KIR2DL4.

[0026] Fig. 8 shows certain clones as novel anti-KIR binding agents (single-specific in bold, multi-specific non-bolded).

[0027] Figs. 9-18 show data generated for anti-KIR2DS1 clones by methodologies described herein.

[0028] Figs. 19-28 show data generated for anti-KIR3DL2 clones by methodologies described herein.

[0029] Figs. 29-35 show data generated for anti-KIR2DS4 clones by methodologies described herein.

[0030] Figs. 36-41 show data generated for anti-KIR3DL1 clones by methodologies described herein.

[0031] Figs. 42-48 show data generated for anti-KIR2DL5 clones by methodologies described herein.

[0032] Fig. 49 shows certain clones cover broader polymorphic variants than currently available clones for KIR2DL5. For example, clone S22010E is able to bind to more polymorphic KIR2DL5 variants than commercial clone UP-R1 , better covering for donor-dependent KIR expression differences. Top panel: Staining of Ba / F3 cells expressing different KIR2DL5 polymorphic variants with clones S22010E and UP-R1 . Bottom panel: SNP variants of KIR2DL5 at positions 141 , 173, and 195.

[0033] Figs. 50-54 show data generated for anti-KIR2DL5 clones by methodologies described herein.

[0034] Figs. 55-59 show data generated for anti-KIR3DL3 clones by methodologies described herein.

[0035] Figs. 60-63 show data generated for anti-KIR2DS5 clones by methodologies described herein.

[0036] Figs. 64-101 show data generated for anti-KIR2DL1 , anti-KIR2DL2, anti-KIR2DS2, and / or anti- KIR2DL3 clones by methodologies described herein.

[0037] Fig. 102 shows certain KIR-specific clones can characterize KIR positive NK populations. Data shown is pre-gated on a lymphocyte population of peripheral blood, and samples were stained with anti-CD56 APC and specific clones as indicated. Cells were analyzed by flow cytometry. Figs. 103A-103C show certain clones can affect KIR-ligand interactions. Fig. 103A: For KIR2DS1 , HLA-C*04:01 is a reported ligand for KIR2DS1 . The results indicate KIR2DS1 -binding clones S22019F and S22013A block HLA-C*04:01 tetramer from binding to KIR2DS1. Fig. 107B: For KIR3DL2, HLA-A*11 :01 is a reported ligand for KIR3DL2. The results indicate KIR3DL2-binding clone S22025B enhances HLA-A*1 1 :01 tetramer binding to KIR3DL2. Fig. 107C: For KIR3DL3, HHLA2 is a reported ligand for KIR3DL3. The results indicate KIR3DL3-binding clone S23011 E blocks HHLA2 from binding to KIR3DL3.

[0038] Figs. 104-121 show data characterizing the aforementioned anti-KIR clones in relation to other commercial antibodies.

[0039] Fig. 122 shows a representative image of activation in a KIR3DL1 cytotoxicity assay and representative effects of HLA or antibody addition.

[0040] Fig. 123 shows CD107a activation change results from a KIR3DL1 cytotoxicity assay.

[0041] Fig. 124 shows an effect of KIR3DL1 -binding antibody addition to normalized CD107a activation ratio of NK cells in NK-K562 co-culture. NK cells in NK-K562 co-culture were divided and analyzed according to KIR3DL1 positivity. CD107a activation ratio was calculated by the ratio of percentage of NK cells with CD107a positivity compared to percentage of NK cells with CD107a negativity. All samples were normalized to isotype control measurements (MOPC-21 ). **** = p-value <0.0001 , *** = p-value <0.001 by Brown-Forsythe and Welch one-way ANOVA. n = 7 to 21 samples per group.

[0042] Fig. 125 shows a representative image of activation in a KIR2DS1 cytotoxicity assay and representative effects of HLA or antibody addition.

[0043] Fig. 126 shows an effect of KIR2DS1 -specific antibody addition to normalized CD107a activation ratio of NK cells in NK-K562 co-culture. NK cells in NK-K562 co-culture were divided and analyzed according to KIR2DS1 positivity. CD107a activation ratio was calculated by the ratio of percentage of NK cells with CD107a positivity compared to percentage of NK cells with CD107a negativity. All samples were normalized to isotype control measurements (MOPC-21 ). **** = p-value <0.0001 , *** = p-value <0.001 by Brown-Forsythe and Welch two-way ANOVA. n = 16 samples per group.

[0044] Fig. 127 shows a representative image of activation in a KIR2DS4 cytotoxicity assay and representative effects of HLA or antibody addition.

[0045] Fig. 128 shows an effect of KIR2DS4-specific antibody addition to change in activated NK cells in NK-K562 co-culture. NK cells in NK-K562 co-culture were divided and analyzed according to CD107a positivity. Samples were normalized to isotype control (MOPC-21 ) and statistical comparisons of CD107a+ made to isotype control. *** = p-value <0.001 , ** = p-value <0.01 , ns = not significant by Turkey two-way ANOVA. n = 11 to 22 samples per group.

[0046] Fig. 129 shows an effect of KIR2DS4-specific antibody addition to TNFa and IFNy secretion in NK- K562 co-culture. NK-K562 co-culture supernatant was analyzed for TNFa and IFNy concentration in solution. Samples were normalized to isotype control (MOPC-21 ) and statistical comparisons of analyte made to isotype control. ** = p-value <0.01 , * = p-value <0.05, ns = not significant by Brown-Forscythe and Welch one-way ANOVA. n = 8 to 16 samples per group.

[0047] Fig. 130 shows an effect of KIR2DS4-specific antibody addition to K562 survival in NK-K562 coculture. K562 cells in NK-K562 co-culture were divided and analyzed according to Apotracker Green positivity. Samples were normalized to isotype control (MOPC-21 ) and statistical comparisons of K562 percentage made to isotype control. **** = p-value <0.0001 , ns = not significant by Turkey two-way ANOVA. n = 1 1 to 22 samples per group.

[0048] Figs. 131 -132 show ligand binding interaction data generated for anti-KIR2DL1 clones by methodologies described herein.

[0049] Figs. 133-136 show ligand binding interaction data generated for anti-KIR2DL2, anti-KIR2DS2, and anti-KIR2DL3 clones by methodologies described herein.

[0050] Figs. 137-139 show ligand binding interaction data generated for anti-KIR3DL1 clones by methodologies described herein.

[0051] Figs. 140-142 show ligand binding interaction data generated for anti-KIR2DS4 clones by methodologies described herein.

[0052] Fig. 143 shows ligand binding interaction data generated for anti-KIR2DL5 clones by methodologies described herein.

[0053] Fig. 144 shows certain clones can affect KIR-ligand interactions. KIR2DL5A transfected Ba / F3 cells were incubated with CD155-FC, CD112-FC, or CD1 13-FC. Anti-FC antibody was used to detect the binding in flow cytometry. As indicated, certain clones were added to cells before ligand incubation to determine if the clones can affect ligand binding. CD155 has previously been reported to be a ligand of KIR2DL5; CD112 and CD113 which are similar to CD155, were used as negative controls. The results indicate KIR2DL5A-binding clone S22010G enhances CD155 binding to KIR2DL5A.

[0054] Figs. 145-147 show ligand binding interaction data generated for anti-KIR2DS1 clones by methodologies described herein. Figs. 148-150 show ligand binding interaction data generated for anti-KIR3DL2 clones by methodologies described herein.

[0055] Figs. 151 -152 show ligand binding interaction data generated for anti-KIR3DL3 clones by methodologies described herein.

[0056] Detailed Description

[0057] Provided herein are killer cell immunoglobulin-like receptor (KIR) binding antibodies (e.g., antibodies that bind to KIR2DL1 , KIR2DL2, KIR2DL3, KIR2DL4, KIR2DL5, KIR2DS1 , KIR2DS2, KIR2DS4, KIR2DS5, KIR3DL1 , KIR3DL2, and / or KIR3DL3) and antigen binding fragments thereof, nucleic acids encoding such antibodies, components thereof, and antigen-binding fragments thereof. Also provided herein are vectors (e.g., recombinant expression vectors) and cells (e.g., recombinant cells) for expression and production of the antibodies and antigen-binding fragments. In some embodiments, antibodies and antigen binding fragments thereof can bind to KIR under physiological and / or in vitro conditions. Also provided are methods of producing and using KIR binding antibodies and antigen-binding fragments thereof such as in methods for detecting KIR in a sample from an individual, including methods for laboratory / research purposes (e.g., flow cytometry, ELISA, and / or Western blot), and / or for the use and treatment and / or prevention of various diseases or disorders through the delivery of pharmaceutical or other compositions that contain such antibodies or antigen-binding fragments thereof.

[0058] Anti-KIR agents

[0059] Provided herein are agents that bind killer cell immunoglobulin-like receptor (KIR) or a portion thereof. For example, provided herein are agents that bind KIR2DL1 , KIR2DL2, KIR2DL3, KIR2DL4, KIR2DL5, KIR2DS1 , KIR2DS2, KIR2DS4, KIR2DS5, KIR3DL1 , KIR3DL2, and / or KIR3DL3 or portions thereof. Killer cell immunoglobulin-like receptor (KIR) is also known as CD158. Agents that bind KIR or a portion thereof may be referred to as anti-KIR agents and may include anti-KIR antibodies, anti-KIR antibody fragments (e.g., antigen binding fragments), and anti-KIR antibody derivatives. In some embodiments, the agent is isolated (e.g., separated from a component of its natural environment (e.g., an animal, a biological sample)). In some embodiments, the agent is non-naturally occurring (e.g., produced by human intervention). In some embodiments, the agent is a humanized antibody, or an antigen binding fragment thereof. In some embodiments, the agent is a derivative of a humanized antibody that binds KIR.

[0060] In some embodiments, the agent binds KIR under laboratory conditions (e.g., binds KIR in vitro, binds KIR in a flow cytometry assay, binds KIR in an ELISA). In some embodiments, the agent binds KIR under physiological conditions (e.g., binds KIR in a cell in a subject). In some embodiments, the agent affects KIR signaling. In some embodiments, the agent blocks or is capable of blocking KIR signaling. In some embodiments, the agent enhances or is capable of enhancing KIR signaling. In some embodiments, the agent affects ligand binding to KIR. In some embodiments, the agent blocks or is capable of blocking ligand binding to KIR. For example, an anti-KIR agent herein may block binding of HLA-C*04:01 to KIR2DS1. In another example, an anti- KIR agent herein may block binding of HHLA2 to KIR3DL3. In some embodiments, the agent enhances or is capable of enhancing ligand binding to KIR. For example, an anti-KIR agent provided herein may enhance binding of CD155 to KIR2DL5A. In another example, an anti-KIR agent provided herein may enhance binding of HLA-A*11 :01 to KIR3DL2. KIR ligand binding may be assessed using any suitable assay, such as a ligand binding assay as demonstrated in Example 2, Figs. 103A-C, and Figs. 131 -152, for example.

[0061] In some embodiments, the agent affects immune cell activity. In some embodiments, the agent affects natural killer cell activity. In some embodiments, the agent inhibits natural killer cell activity. In some embodiments, the agent activates natural killer cell activity. Natural killer cell activity may be assessed using any suitable assay, such as a cytotoxicity assay (e.g., degranulation assay as measured by a release of cytotoxic granules, which is marked by surface expression of CD107a), a cytokine (e.g., TNFa, IFNy) expression and / or secretion assay, and a natural killer target cell survival assay (e.g., K562 cell survival assay) as demonstrated in Example 2 and Figs. 122-130.

[0062] Generally, an anti-KIR agent provided herein comprises at least one immunoglobulin heavy chain variable domain and at least one immunoglobulin light chain variable domain. In some embodiments, an anti-KIR agent herein comprises two immunoglobulin heavy chain variable domains and two immunoglobulin light chain variable domains. Typically, each immunoglobulin heavy chain variable domain of the anti-KIR agent comprises first, second, and third heavy chain complementarity determining regions (CDRs; CDRH1 , CDRH2, CDRH3), and each immunoglobulin light chain variable domain of the anti-KIR agent comprises first, second, and third light chain CDRs (CDRL1 , CDRL2, CDRL3).

[0063] In some embodiments, an anti-KIR agent provided herein comprises a heavy chain complementarity determining region 1 (CDRH1 ) comprising a CDRHI polypeptide provided in Table 3, or a polypeptide that is at least 80 percent identical to a CDRH1 polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises a CDRH1 comprising a polypeptide that is at least 85 percent identical to a CDRH1 polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises a CDRH1 comprising a polypeptide that is at least 90 percent identical to a CDRH1 polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises a CDRH1 comprising a polypeptide that is at least 95 percent identical to a CDRH1 polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises a CDRH1 comprising a polypeptide that is 100 percent identical to a CDRH1 polypeptide provided in Table 3.

[0064] In some embodiments, an anti-KIR agent provided herein comprises a heavy chain complementarity determining region 2 (CDRH2) comprising a CDRH2 polypeptide provided in Table 3, or a polypeptide that is at least 80 percent identical to a CDRH2 polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises a CDRH2 comprising a polypeptide that is at least 85 percent identical to a CDRH2 polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises a CDRH2 comprising a polypeptide that is at least 90 percent identical to a CDRH2 polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises a CDRH2 comprising a polypeptide that is at least 95 percent identical to a CDRH2 polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises a CDRH2 comprising a polypeptide that is 100 percent identical to a CDRH2 polypeptide provided in Table 3.

[0065] In some embodiments, an anti-KIR agent provided herein comprises a heavy chain complementarity determining region 3 (CDRH3) comprising a CDRH3 polypeptide provided in Table 3, or a polypeptide that is at least 80 percent identical to a CDRH3 polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises a CDRH3 comprising a polypeptide that is at least 85 percent identical to a CDRH3 polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises a CDRH3 comprising a polypeptide that is at least 90 percent identical to a CDRH3 polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises a CDRH3 comprising a polypeptide that is at least 95 percent identical to a CDRH3 polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises a CDRH3 comprising a polypeptide that is at 100 percent identical to a CDRH3 polypeptide provided in Table 3.

[0066] In some embodiments, an anti-KIR agent provided herein comprises a light chain complementarity determining region 1 (CDRL1 ) comprising a CDRL1 polypeptide provided in Table 3, or a polypeptide that is at least 80 percent identical to a CDRL1 polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises a CDRL1 comprising a polypeptide that is at least 85 percent identical to a CDRL1 polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises a CDRL1 comprising a polypeptide that is at least 90 percent identical to a CDRL1 polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises a CDRL1 comprising a polypeptide that is at least 95 percent identical to a CDRL1 polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises a CDRL1 comprising a polypeptide that is 100 percent identical to a CDRL1 polypeptide provided in Table 3.

[0067] In some embodiments, an anti-KIR agent provided herein comprises a light chain complementarity determining region 2 (CDRL2) comprising a CDRL2 polypeptide provided in Table 3, or a polypeptide that is at least 80 percent identical to a CDRL2 polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises a CDRL2 comprising a polypeptide that is at least 85 percent identical to a CDRL2 polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises a CDRL2 comprising a polypeptide that is at least 90 percent identical to a CDRL2 polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises a CDRL2 comprising a polypeptide that is at least 95 percent identical to a CDRL2 polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises a CDRL2 comprising a polypeptide that is 100 percent identical to a CDRL2 polypeptide provided in Table 3.

[0068] In some embodiments, an anti-KIR agent provided herein comprises a light chain complementarity determining region 3 (CDRL3) comprising a CDRL3 polypeptide provided in Table 3, or a polypeptide that is at least 80 percent identical to a CDRL3 polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises a CDRL3 comprising a polypeptide that is at least 85 percent identical to a CDRL3 polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises a CDRL3 comprising a polypeptide that is at least 90 percent identical to a CDRL3 polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises a CDRL3 comprising a polypeptide that is at least 95 percent identical to a CDRL3 polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises a CDRL3 comprising a polypeptide that is at least 100 percent identical to a CDRL3 polypeptide provided in Table 3.

[0069] In some embodiments, an anti-KIR agent provided herein binds to KIR2DS1 or a portion thereof, which may be referred to herein as an anti-KIR2DS1 agent. In some embodiments, an anti- KIR2DS1 agent comprises a CDRH1 comprising a polypeptide provided in Table 3, a CDRH2 comprising a polypeptide provided in Table 3, a CDRH3 comprising a polypeptide provided in Table 3, a CDRL1 comprising a polypeptide provided in Table 3, a CDRL2 comprising a polypeptide provided in Table 3, and a CDRL3 comprising a polypeptide provided in Table 3, or one or more variants of each thereof. For example, in some embodiments, an anti-KIR2DS1 agent comprises a CDRH1 comprising the polypeptide GYX1FTX2X3W where Xi is S or T, X2 is T or R, and X3is Y or N. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e. , conservative to S and / or T). In some embodiments, the amino acid Xi may be substituted with S, T, C, N, A, or G. In some embodiments, the amino acid Xi may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to T and / or R). In some embodiments, the amino acid X2may be substituted with T, R, S, C, N, A, K, or H. The amino acid X3may be substituted with any amino acid. In some embodiments, the amino acid X3may be substituted with a conservative amino acid (i.e., conservative to Y and / or N). In some embodiments, the amino acid X3may be substituted with Y, N, F, W, S, T, H, Q, or D. In some embodiments, the amino acid X3may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). In some embodiments, an anti-KIR2DS1 agent comprises a CDRL2 comprising the polypeptide XiTS where Xi is Y or R. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to Y and / or R). In some embodiments, the amino acid Xi may be substituted with Y, R, F, W, H, S, T, K, H, or Q. In some embodiments, an anti-KIR2DS1 agent comprises a CDRL3 comprising the polypeptide QQGXiX2X3PX4T where Xi is K or S, X2is T or S, X3is L or I, and X4 is Y or L. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to K and / or S). In some embodiments, the amino acid Xi may be substituted with K, S, R, H, T, C, N, or G. The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to T and / or S). In some embodiments, the amino acid X2may be substituted with T, S, C, N, A, or G. In some embodiments, the amino acid X2may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). The amino acid X3may be substituted with any amino acid. In some embodiments, the amino acid X3may be substituted with a conservative amino acid (i.e., conservative to L and / or I). In some embodiments, the amino acid X3may be substituted with L, I, V, M, A, or F. In some embodiments, the amino acid X3may be substituted with a nonpolar amino acid (e.g., A, G, I, L, M, F, P, W, V). The amino acid X4 may be substituted with any amino acid. In some embodiments, the amino acid X4may be substituted with a conservative amino acid (i.e., conservative to Y and / or L). In some embodiments, the amino acid X4may be substituted with Y, L, F, W, H, S, T, I, V, M, or A.

[0070] In some embodiments, an anti-KIR agent provided herein binds to KIR2DS4 or a portion thereof, which may be referred to herein as an anti-KIR2DS4 agent. In some embodiments, an anti- KIR2DS4 agent comprises a CDRH1 comprising a polypeptide provided in Table 3, a CDRH2 comprising a polypeptide provided in Table 3, a CDRH3 comprising a polypeptide provided in Table 3, a CDRL1 comprising a polypeptide provided in Table 3, a CDRL2 comprising a polypeptide provided in Table 3, and a CDRL3 comprising a polypeptide provided in Table 3, or one or more variants of each thereof. For example, in some embodiments, an anti-KIR2DS4 agent comprises a CDRH1 comprising the polypeptide GYSFXIGYX2where Xi is T or S and X2is T or Y. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to T and / or S). In some embodiments, the amino acid Xi may be substituted with T, S, C, N, A, or G. In some embodiments, the amino acid Xi may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to T and / or Y). In some embodiments, the amino acid X2may be substituted with T, S, C, N, A, F, W, or H. In some embodiments, the amino acid X2may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). In some embodiments, an anti-KIR2DS4 agent comprises a CDRH2 comprising the polypeptide IHPYNGX1T where Xi is D or A. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to D and / or A). In some embodiments, the amino acid Xi may be substituted with D, A, E, N, S, G, V, or L. In some embodiments, an anti-KIR2DS4 agent comprises a CDRH2 comprising the polypeptide ISYSXIX2T where Xi is G or A and X2is S or T. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to G and / or A). In some embodiments, the amino acid Xi may be substituted with G, A, V, S, L, P, or C. In some embodiments, the amino acid Xi may be substituted with a nonpolar amino acid (e.g., A, G, I, L, M, F, P, W, V). The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to S and / or T). In some embodiments, the amino acid X2may be substituted with T, S, C, N, A, or G. In some embodiments, the amino acid X2may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). In some embodiments, an anti-KIR2DS4 agent comprises a CDRH3 comprising the polypeptide ARXIX2GSX3X4X5AWFAY where Xi is Q or R, X2is Y or A, X3is no amino acid or S, X4 is no amino acid or Y, and X5is L or K. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to Q and / or R). In some embodiments, the amino acid Xi may be substituted with Q, R, N, E, H, S, T, or K. The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to Y and / or A). In some embodiments, the amino acid X2may be substituted with Y, A, F, W, H, S, T, G, V, or L. The amino acid X3may be substituted with any amino acid. In some embodiments, the amino acid X3may be substituted with a conservative amino acid (i.e., conservative to S). In some embodiments, the amino acid X3may be substituted with S, T, C, N, or G. In some embodiments, the amino acid X3may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). The amino acid X4may be substituted with any amino acid. In some embodiments, the amino acid X4may be substituted with a conservative amino acid (i.e., conservative to Y). In some embodiments, the amino acid X4may be substituted with Y, F, W, H, S, or T. In some embodiments, the amino acid X4may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). In some embodiments, the amino acid X4may be substituted with an aromatic amino acid (e.g., F, Y, W, H). The amino acid X5may be substituted with any amino acid. In some embodiments, the amino acid Xs may be substituted with a conservative amino acid (i.e., conservative to L and / or K). In some embodiments, the amino acid Xs may be substituted with L, K,

[0071] R, H, I, V, M, A, or F. In some embodiments, an anti-KIR2DS4 agent comprises a CDRH3 comprising the polypeptide XiX2SKYX3NSYAX4DY where Xi is T or A, X2is R or Q, X3is A or S, and X4is V or M. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to T and / or A). In some embodiments, the amino acid Xi may be substituted with T, A,

[0072] S, C, N, G, V, or L. The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to R and / or Q). In some embodiments, the amino acid X2may be substituted with R, Q, K, H, N, E, S, or T. The amino acid X3may be substituted with any amino acid. In some embodiments, the amino acid X3may be substituted with a conservative amino acid (i.e., conservative to A and / or S). In some embodiments, the amino acid X3may be substituted with A, S, G, V, L, T, C, or N. The amino acid X4may be substituted with any amino acid. In some embodiments, the amino acid X4may be substituted with a conservative amino acid (i.e., conservative to V and / or M). In some embodiments, the amino acid X4may be substituted with V, M, I, L, A, or F. In some embodiments, the amino acid X4may be substituted with a nonpolar amino acid (e.g., A, G, I, L, M, F, P, W, V). In some embodiments, an anti-KIR2DS4 agent comprises a CDRL2 comprising the polypeptide GX1S where Xi is A or S. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to A and / or S). In some embodiments, the amino acid Xi may be substituted with A, S, G, V, L, T, C, or N. In some embodiments, an anti-KIR2DS4 agent comprises a CDRL3 comprising the polypeptide QNDHX1YPPT where Xi is S or I. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to S and / or I). In some embodiments, the amino acid Xi may be substituted with S, I, T, C, N, G, L, V, M, A, or F. In some embodiments, an anti-KIR agent provided herein binds to KIR3DL1 or a portion thereof, which may be referred to herein as an anti-KIR3DL1 agent. In some embodiments, an anti- KIR3DL1 agent comprises a CDRH1 comprising a polypeptide provided in Table 3, a CDRH2 comprising a polypeptide provided in Table 3, a CDRH3 comprising a polypeptide provided in Table 3, a CDRL1 comprising a polypeptide provided in Table 3, a CDRL2 comprising a polypeptide provided in Table 3, and a CDRL3 comprising a polypeptide provided in Table 3, or one or more variants of each thereof. For example, in some embodiments, an anti-KIR3DL1 agent comprises a CDRH1 comprising the polypeptide GYX1FX2X3YX4 where Xi is S or T, X2is T or S, X3is D or T or N, and X4 is T, Y, S, A or W. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to S and / or T). In some embodiments, the amino acid Xi may be substituted with S, T, C, N, A, or G. In some embodiments, the amino acid Xi may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to T and / or S). In some embodiments, the amino acid X2may be substituted with S, T, C, N, A, or G. In some embodiments, the amino acid X2may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). The amino acid X3may be substituted with any amino acid. In some embodiments, the amino acid X3may be substituted with a conservative amino acid (i.e., conservative to D and / or T and / or N). In some embodiments, the amino acid X3may be substituted with D, T, N, E, S, C, A, Q, or H. The amino acid X4may be substituted with any amino acid. In some embodiments, the amino acid X4 may be substituted with a conservative amino acid (i.e., conservative to T and / or Y and / or S and / or A and / or W). In some embodiments, the amino acid X4 may be substituted with S, T, C, N, A, G, F, W, H, V, L, Y, or M. In some embodiments, an anti- KIR3DL1 agent comprises a CDRH2 comprising the polypeptide INPXiX2GX3T where Xi is S or Y, X2is S or N, and X3is Y or G. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to S and / or Y). In some embodiments, the amino acid Xi may be substituted with S, Y, T, C, N, G, F, W, or H. In some embodiments, the amino acid Xi may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to S and / or N). In some embodiments, the amino acid Xi may be substituted with S, N, T, C, N, G, Q, D, or H. In some embodiments, the amino acid X2may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to Y and / or G). In some embodiments, the amino acid Xi may be substituted with Y, G, A, S, P, C, F, W, H, or T. In some embodiments, an anti-KIR3DL1 agent comprises a CDRH2 comprising the polypeptide INTXIX2GX3X4where Xi is E or Y, X2is T or Y, X3is E or D, and X4is P or A. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to E and / or Y). In some embodiments, the amino acid Xi may be substituted with E, Y, F, W, H, S, T, D, Q, or N. The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to T and / or Y). In some embodiments, the amino acid X2may be substituted with T, Y, F, W, H, S, C, N, or A. In some embodiments, the amino acid X2may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). The amino acid X3may be substituted with any amino acid. In some embodiments, the amino acid X3may be substituted with a conservative amino acid (i.e., conservative to E and / or D). In some embodiments, the amino acid X3may be substituted with E, D, N, S, or Q. In some embodiments, the amino acid X3may be substituted with a negatively charged amino acid (e.g., E or D). The amino acid X4may be substituted with any amino acid. In some embodiments, the amino acid X4may be substituted with a conservative amino acid (i.e., conservative to P and / or A). In some embodiments, the amino acid X4may be substituted with P, A, G, L, V, or S. In some embodiments, the amino acid X4may be substituted with a nonpolar amino acid (e.g., A, G, I, L, M, F, P, W, V). In some embodiments, an anti-KIR3DL1 agent comprises a CDRL1 comprising the polypeptide ENIYSX1 where Xi is N or Y. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to N and / or Y). In some embodiments, the amino acid Xi may be substituted with N, Y, F, W, H, S, T, Q, or D. In some embodiments, the amino acid Xi may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). In some embodiments, an anti-KIR3DL1 agent comprises a CDRL1 comprising the polypeptide QSLLXISX2NQKNY where Xi is F or N and X2is S or G. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to F and / or N). In some embodiments, the amino acid Xi may be substituted with F, N, Q, S, T, D, H, Y, W, L, M, I, or V. The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to S and / or G). In some embodiments, the amino acid X2may be substituted with S, G, T, C, N, A, or P. In some embodiments, an anti-KIR3DL1 agent comprises a CDRL2 comprising the polypeptide AAX1 where Xi is R or S. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to R and / or S). In some embodiments, the amino acid Xi may be substituted with R, S, T, C, N, G, K, H, or Q. In some embodiments, an anti- KIR3DL1 agent comprises a CDRL2 comprising the polypeptide XiAS where Xi is W or G. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to W and / or G). In some embodiments, the amino acid Xi may be substituted with W, G, A, S, P, C, F, Y, H, L, or M. In some embodiments, the amino acid Xi may be substituted with a nonpolar amino acid (e.g., A, G, I, L, M, F, P, W, V). In some embodiments, an anti-KIR3DL1 agent comprises a CDRL3 comprising the polypeptide QHX1X1GTPLT where Xi is F or H and X2is W or Y. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to F and / or H). In some embodiments, the amino acid Xi may be substituted with F, H, Y, W, L, M, I, V, K, R, N, or Q. In some embodiments, the amino acid Xi may be substituted with an aromatic amino acid (e.g., F, Y, W, H). The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to W and / or Y). In some embodiments, the amino acid X2may be substituted with W, Y, F, H, L, M, S, or T. In some embodiments, the amino acid X2may be substituted with an aromatic amino acid (e.g., F, Y, W, H). In some embodiments, an anti- KIR3DL1 agent comprises a CDRL3 comprising the polypeptide XIQSX2X3X4PYT where Xi is S or Q, X2is T or N, X3 is H or E, and X4 is V or D. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to S and / or Q). In some embodiments, the amino acid Xi may be substituted with S, Q, T, C, N, G, E, H, or K. In some embodiments, the amino acid Xi may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to T and / or N). In some embodiments, the amino acid X2may be substituted with T, N, S, C, A, Q, D, or H. In some embodiments, the amino acid X2may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). The amino acid X3may be substituted with any amino acid. In some embodiments, the amino acid X3may be substituted with a conservative amino acid (i.e., conservative to H and / or E). In some embodiments, the amino acid X3may be substituted with H, E, D, Q, N, S, K, R, Y, or W. The amino acid X4 may be substituted with any amino acid. In some embodiments, the amino acid X4may be substituted with a conservative amino acid (i.e., conservative to V and / or D). In some embodiments, the amino acid X4may be substituted with V, D, I, L, A, M, E, N, or S.

[0073] In some embodiments, an anti-KIR agent provided herein binds to KIR3DL3 or a portion thereof, which may be referred to herein as an anti-KIR3DL3 agent. In some embodiments, an anti- KIR3DL3 agent comprises a CDRH1 comprising a polypeptide provided in Table 3, a CDRH2 comprising a polypeptide provided in Table 3, a CDRH3 comprising a polypeptide provided in Table 3, a CDRL1 comprising a polypeptide provided in Table 3, a CDRL2 comprising a polypeptide provided in Table 3, and a CDRL3 comprising a polypeptide provided in Table 3, or one or more variants of each thereof. For example, in some embodiments, an anti-KIR3DL3 agent comprises a CDRH2 comprising the polypeptide IHYSGXiT where Xi is T or S. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e. , conservative to T and / or S). In some embodiments, the amino acid Xi may be substituted with T, S, C, N, A, or G. In some embodiments, the amino acid Xi may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). In some embodiments, an anti-KIR3DL3 agent comprises a CDRL3 comprising the polypeptide QQWSSX1PLT where Xi is D or N. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to D and / or N). In some embodiments, the amino acid Xi may be substituted with D, N, E, S, Q, T, or H.

[0074] In some embodiments, an anti-KIR agent provided herein binds to KIR2DL2 or a portion thereof and KIR2DS2 or a portion thereof, which may be referred to herein as an anti-KIR2DL2 / KIR2DS2 agent. In some embodiments, an anti-KIR2DL2 / KIR2DS2 agent comprises a CDRH1 comprising a polypeptide provided in Table 3, a CDRH2 comprising a polypeptide provided in Table 3, a CDRH3 comprising a polypeptide provided in Table 3, a CDRL1 comprising a polypeptide provided in Table 3, a CDRL2 comprising a polypeptide provided in Table 3, and a CDRL3 comprising a polypeptide provided in Table 3, or one or more variants of each thereof. For example, in some embodiments, an anti-KIR2DL2 / KIR2DS2 agent comprises a CDRH1 comprising the polypeptide GX1SX2TSX3X4 where Xi is D or F, X2is I or L, X3is G or Y, and X4is F or G. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to D and / or F). In some embodiments, the amino acid Xi may be substituted with D, F, Y, W, L, M, I, V, E, N, or S. The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to I and / or L). In some embodiments, the amino acid X2may be substituted with I, L, V, M, A, or F. In some embodiments, the amino acid X2may be substituted with a nonpolar amino acid (e.g., A, G, I, L, M, F, P, W, V). The amino acid X3may be substituted with any amino acid. In some embodiments, the amino acid X3may be substituted with a conservative amino acid (i.e., conservative to G and / or Y). In some embodiments, the amino acid X3may be substituted with G, Y, F, W, H, S, T, A, P, or C. The amino acid X4may be substituted with any amino acid. In some embodiments, the amino acid X4may be substituted with a conservative amino acid (i.e., conservative to F and / or G). In some embodiments, the amino acid X4may be substituted with F, G, A, S, P, C, Y, W, L, M, I, or V. In some embodiments, the amino acid X4may be substituted with a nonpolar amino acid (e.g., A, G, I, L, M, F, P, W, V). In some embodiments, an anti-KIR2DL2 / KIR2DS2 agent comprises a CDRH2 comprising the polypeptide IX1X2X3GST where Xi is S or W, X2is Y or T, and X3is S or G. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to S and / or W). In some embodiments, the amino acid Xi may be substituted with S, W, F, Y, H, L, M, T, C, N, or G. The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to Y and / or T). In some embodiments, the amino acid X2may be substituted with Y, T, S, C, N, A, F, W, or H. In some embodiments, the amino acid X2may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). The amino acid X3may be substituted with any amino acid. In some embodiments, the amino acid X3may be substituted with a conservative amino acid (i.e., conservative to S and / or G). In some embodiments, the amino acid X3may be substituted with S, G, T, C, N, A, or P. In some embodiments, an anti- KIR2DL2 / KIR2DS2 agent comprises a CDRL1 comprising the polypeptide QSLLNSXiX2X3KNY, where Xi is F or R, X2is N or T, and X3is Q or R. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to F and / or R). In some embodiments, the amino acid Xi may be substituted with F, R, Y, W, L, M, I, V, K, H, Q, or N. The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to N and / or T). In some embodiments, the amino acid X2may be substituted with N, T, S, C, A, Q, D, or H. In some embodiments, the amino acid X2may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). The amino acid X3may be substituted with any amino acid. In some embodiments, the amino acid X3may be substituted with a conservative amino acid (i.e., conservative to Q and / or R). In some embodiments, the amino acid X3may be substituted with Q, R, N, E, H, S, T, or K. In some embodiments, an anti-KIR2DL2 / KIR2DS2 agent comprises a CDRL2 comprising the polypeptide X1AS where Xi is F or W. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to F and / or W). In some embodiments, the amino acid Xi may be substituted with F, W, Y, H, L, M, or V. In some embodiments, the amino acid Xi may be substituted with a nonpolar amino acid (e.g., A, G, I, L, M, F, P, W, V). In some embodiments, the amino acid Xi may be substituted with an aromatic amino acid (e.g., F, Y, W, H). In some embodiments, an anti-KIR2DL2 / KIR2DS2 agent comprises a CDRL3 comprising the polypeptide XIQX2YNX3PX4T where Xi is Q or K, X2is Y or S, X3is T or L, and X4is V or W. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to Q and / or K). In some embodiments, the amino acid Xi may be substituted with Q, K, N, E, H, S, T, or R. The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to Y and / or S). In some embodiments, the amino acid X2may be substituted with Y, S, T, C, N, G, F, W, or H. In some embodiments, the amino acid X2may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). The amino acid X3may be substituted with any amino acid. In some embodiments, the amino acid X3may be substituted with a conservative amino acid (i.e., conservative to T and / or L). In some embodiments, the amino acid X3may be substituted with T, L, S, C, N, A, I, V, M, or F. The amino acid X4may be substituted with any amino acid. In some embodiments, the amino acid X4may be substituted with a conservative amino acid (i.e., conservative to V and / or W). In some embodiments, the amino acid X4may be substituted with V, W, I, L, A, M, F, Y, or H. In some embodiments, the amino acid X4may be substituted with a nonpolar amino acid (e.g., A, G, I, L, M, F, P, W, V).

[0075] In some embodiments, an anti-KIR agent provided herein binds to KIR2DL3 or a portion thereof, KIR2DL2 or a portion thereof, and KIR2DS2 or a portion thereof, which may be referred to herein as an anti-KIR2DL3 / KIR2DL2 / KIR2DS2 agent. In some embodiments, an anti- KIR2DL3 / KIR2DL2 / KIR2DS2 agent comprises a CDRH1 comprising a polypeptide provided in Table 3, a CDRH2 comprising a polypeptide provided in Table 3, a CDRH3 comprising a polypeptide provided in Table 3, a CDRL1 comprising a polypeptide provided in Table 3, a CDRL2 comprising a polypeptide provided in Table 3, and a CDRL3 comprising a polypeptide provided in Table 3, or one or more variants of each thereof. For example, in some embodiments, an anti- KIR2DL3 / KIR2DL2 / KIR2DS2 agent comprises a CDRH1 comprising the polypeptide GXiTFX2X3YX4where Xi is Y or F, X2is T, K or N, X3is D or N, and X4is A or D. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to Y and / or F). In some embodiments, the amino acid Xi may be substituted with Y, F, W, H, S, T, L, M, I, or V. In some embodiments, the amino acid Xi may be substituted with an aromatic amino acid (e.g., F, Y, W, H). The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to T and / or K and / or N). In some embodiments, the amino acid X2may be substituted with T, K, S, C, N, A, R, and H. The amino acid X3may be substituted with any amino acid. In some embodiments, the amino acid X3may be substituted with a conservative amino acid (i.e., conservative to D and / or N). In some embodiments, the amino acid X3may be substituted with D, N, E, S, Q, T, or H. The amino acid X4may be substituted with any amino acid. In some embodiments, the amino acid X4may be substituted with a conservative amino acid (i.e., conservative to A and / or D). In some embodiments, the amino acid X4may be substituted with A, D, G, V, S, L, E, or N. In some embodiments, an anti-KIR2DL3 / KIR2DL2 / KIR2DS2 agent comprises a CDRH1 comprising the polypeptide GFTFX1X2X3X4 where Xi is N or K, X2is T or N, X3is N or Y, and X4is A or D. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to N and / or K). In some embodiments, the amino acid Xi may be substituted with N, K, Q, S, T, D, H, or R. The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to T and / or N). In some embodiments, the amino acid X2may be substituted with T, N, S, C, A, Q, D, or H. In some embodiments, the amino acid X2may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). The amino acid X3may be substituted with any amino acid. In some embodiments, the amino acid X3may be substituted with a conservative amino acid (i.e., conservative to N and / or Y). In some embodiments, the amino acid X3may be substituted with N, Y, Q, S, T, D, H, F, or W. In some embodiments, the amino acid X3may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). The amino acid X4may be substituted with any amino acid. In some embodiments, the amino acid X4may be substituted with a conservative amino acid (i.e., conservative to A and / or D). In some embodiments, the amino acid X4may be substituted with A, D, G, V, S, L, E, or N. In some embodiments, an anti-KIR2DL3 / KIR2DL2 / KIR2DS2 agent comprises a CDRH1 comprising the polypeptide GXITFX2X3X4A where Xi is F or Y, X2is N or T, X3is T or D, and X4is N or Y. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to F and / or Y). In some embodiments, the amino acid Xi may be substituted with F, Y, W, H, S, T, L, M, I, or V. In some embodiments, the amino acid Xi may be substituted with an aromatic amino acid (e.g., F, Y, W, H). The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to N and / or T). In some embodiments, the amino acid X2may be substituted with N, T, Q, S, D, H, C, or A. In some embodiments, the amino acid X2may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). The amino acid X3may be substituted with any amino acid. In some embodiments, the amino acid X3may be substituted with a conservative amino acid (i.e., conservative to T and / or D). In some embodiments, the amino acid X3may be substituted with T, D, S, C, N, A, or E. The amino acid X4may be substituted with any amino acid. In some embodiments, the amino acid X4may be substituted with a conservative amino acid (i.e., conservative to N and / or Y). In some embodiments, the amino acid X4may be substituted with N, Y, F, W, H, S, T, Q, or D. In some embodiments, the amino acid X4may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). In some embodiments, an anti-KIR2DL3 / KIR2DL2 / KIR2DS2 agent comprises a CDRH1 comprising the polypeptide GYXI FTDYX2where Xi is S or T and X2is N or A. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to S and / or T). In some embodiments, the amino acid Xi may be substituted with S, T, C, N, A, or G. In some embodiments, the amino acid Xi may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to N and / or A). In some embodiments, the amino acid X2may be substituted with N, A, G, V, S, L, Q, T, D, or H. In some embodiments, an anti-KIR2DL3 / KIR2DL2 / KIR2DS2 agent comprises a CDRH2 comprising the polypeptide IXIX2X3NGX4T where Xi is D or S, X2is P or T, X3is D or Y, and X4 is G or N. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to D and / or S). In some embodiments, the amino acid Xi may be substituted with D, S, E, N, T, C, or G. The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to P and / or T). In some embodiments, the amino acid X2may be substituted with P, T, S, C, N, A, G, L, or V. The amino acid X3may be substituted with any amino acid. In some embodiments, the amino acid X3may be substituted with a conservative amino acid (i.e., conservative to D and / or Y). In some embodiments, the amino acid X3may be substituted with D, Y, E, N, S, F, W, H, or T. The amino acid X4may be substituted with any amino acid. In some embodiments, the amino acid X4may be substituted with a conservative amino acid (i.e., conservative to G and / or N). In some embodiments, the amino acid X4may be substituted with G, N, A, S, P, C, Q, T, D, or H. In some embodiments, an anti- KIR2DL3 / KIR2DL2 / KIR2DS2 agent comprises a CDRH2 comprising the polypeptide

[0076] IX1 YDGX2X3X4 where Xi is S or T, X2is S or Y, X3is R or I, and X4 is I or T. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to S and / or T). In some embodiments, the amino acid Xi may be substituted with S, T, C, N, A, or G. In some embodiments, the amino acid Xi may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to S and / or Y). In some embodiments, the amino acid X2may be substituted with S, Y, T, C, N, G, F, W, or H. In some embodiments, the amino acid X2may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). The amino acid X3may be substituted with any amino acid. In some embodiments, the amino acid X3may be substituted with a conservative amino acid (i.e., conservative to R and / or I). In some embodiments, the amino acid X3may be substituted with R, I, K, H, Q, N, L, V, M, A, or F. The amino acid X4 may be substituted with any amino acid. In some embodiments, the amino acid X4may be substituted with a conservative amino acid (i.e. , conservative to I and / or T). In some embodiments, the amino acid X4may be substituted with I, T, L, V, M, A, F, S, C, or N. In some embodiments, an anti- KIR2DL3 / KIR2DL2 / KIR2DS2 agent comprises a CDRH3 comprising the polypeptide ARXIX2X3X4YX5X6WFAY where Xi is G or L, X2is D or G, X3is Y or N, X4is G or N, X5is L or G, and X6is R or G. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to G and / or L). In some embodiments, the amino acid Xi may be substituted with G, L, I, V, M, A, F, S, P, or C. In some embodiments, the amino acid Xi may be substituted with a nonpolar amino acid (e.g., A, G, I, L, M, F, P, W, V). The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to D and / or G). In some embodiments, the amino acid X2may be substituted with D, G, A, S, P, C, E, or N. The amino acid X3may be substituted with any amino acid. In some embodiments, the amino acid X3may be substituted with a conservative amino acid (i.e., conservative to Y and / or N). In some embodiments, the amino acid X3may be substituted with Y, N, F, W, H, S, T, Q, or D. In some embodiments, the amino acid X3may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). The amino acid X4may be substituted with any amino acid. In some embodiments, the amino acid X4may be substituted with a conservative amino acid (i.e., conservative to G and / or N). In some embodiments, the amino acid X4may be substituted with G, N, Q, S, T, D, H, A, P, or C. In some embodiments, the amino acid X4may be substituted with a nonpolar amino acid (e.g., A, G, I, L, M, F, P, W, V). The amino acid X5may be substituted with any amino acid. In some embodiments, the amino acid X5may be substituted with a conservative amino acid (i.e., conservative to L and / or G). In some embodiments, the amino acid X5may be substituted with L, G, A, S, P, C, I, V, M, or F. In some embodiments, the amino acid X5 may be substituted with a nonpolar amino acid (e.g., A, G, I, L, M, F, P, W, V). The amino acid X6may be substituted with any amino acid. In some embodiments, the amino acid X6may be substituted with a conservative amino acid (i.e., conservative to R and / or G). In some embodiments, the amino acid X6may be substituted with R, G, K, H, Q, N, A, S, P, or C. In some embodiments, an anti-KIR2DL3 / KIR2DL2 / KIR2DS2 agent comprises a CDRLI comprising the polypeptide QX1 INX1Y where Xi is D or N and X2is S or K. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to D and / or N). In some embodiments, the amino acid Xi may be substituted with D, N, Q, S, T, H, or E. The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to S and / or K). In some embodiments, the amino acid X2may be substituted with S, K, T, C, N, G, R, or H. In some embodiments, an anti-KIR2DL3 / KIR2DL2 / KIR2DS2 agent comprises a CDRL2 comprising the polypeptide KX1S where Xi is V or E. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to V and / or E). In some embodiments, the amino acid Xi may be substituted with V, E, I, L, A, M, D, Q, N, or S. In some embodiments, an anti- KIR2DL3 / KIR2DL2 / KIR2DS2 agent comprises a CDRL2 comprising the polypeptide XiAN where Xi is R or N. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to R and / or N). In some embodiments, the amino acid Xi may be substituted with R, N, Q, S, T, D, H, or K. In some embodiments, an anti-KIR2DL3 / KIR2DL2 / KIR2DS2 agent comprises a CDRL3 comprising the polypeptide X1QX2X3EX4PYT where Xi is Q or L, X2is N or Y, X3 is N or D, and X4 is D or F. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to Q and / or L). In some embodiments, the amino acid Xi may be substituted with Q, L, I, V, M, A, F, N, E, H, S, T, or K. The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to N and / or Y). In some embodiments, the amino acid X2may be substituted with N, Y, F, W, H, S, T, Q, or D. In some embodiments, the amino acid X2may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). The amino acid X3may be substituted with any amino acid. In some embodiments, the amino acid X3may be substituted with a conservative amino acid (i.e., conservative to N and / or D). In some embodiments, the amino acid X3may be substituted with N, D, Q, S, T, H, or E. The amino acid X4 may be substituted with any amino acid. In some embodiments, the amino acid X4 may be substituted with a conservative amino acid (i.e., conservative to D and / or F). In some embodiments, the amino acid X4 inay be substituted with D, F, E, N, S, Y, W, L, M, I, or V.

[0077] In some embodiments, an anti-KIR agent provided herein binds to KIR2DL1 or a portion thereof, KIR2DL2 or a portion thereof, KIR2DL3 or a portion thereof, KIR2DS1 or a portion thereof, and KIR2DS2 or a portion thereof, which may be referred to herein as an anti- KIR2DL1 / KIR2DL2 / KIR2DL3 / KIR2DS1 / KIR2DS2 agent. In some embodiments, an anti- KIR2DL1 / KIR2DL2 / KIR2DL3 / KIR2DS1 / KIR2DS2 agent comprises a CDRH1 comprising a polypeptide provided in Table 3, a CDRH2 comprising a polypeptide provided in Table 3, a CDRH3 comprising a polypeptide provided in Table 3, a CDRL1 comprising a polypeptide provided in Table 3, a CDRL2 comprising a polypeptide provided in Table 3, and a CDRL3 comprising a polypeptide provided in Table 3, or one or more variants of each thereof. For example, in some embodiments, an anti-KIR2DL1 / KIR2DL2 / KIR2DL3 / KIR2DS1 / KIR2DS2 agent comprises a CDRH3 comprising the polypeptide ARXIX2X3X4X5YYGSSX6X7YX8MDY where Xi is no AA or R, X2is no AA or F, X3is S or R, X4 is S or P, X5 is L or N, X6is Y or F, X7 is D or no AA, and X8is V or A. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to R). In some embodiments, the amino acid Xi may be substituted with R, K, H, Q, N. In some embodiments, the amino acid Xi may be substituted with a positively charged amino acid (e.g., K, R, H). The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to F). In some embodiments, the amino acid X2may be substituted with F, Y, W, L, M, I, or V. In some embodiments, the amino acid X2may be substituted with a nonpolar amino acid (e.g., A, G, I, L, M, F, P, W, V). In some embodiments, the amino acid X2may be substituted with an aromatic amino acid (e.g., F, Y, W, H). The amino acid X3may be substituted with any amino acid. In some embodiments, the amino acid X3may be substituted with a conservative amino acid (i.e., conservative to S and / or R). In some embodiments, the amino acid X3may be substituted with S, R, T, C, N, G, K, H, or Q. The amino acid X4may be substituted with any amino acid. In some embodiments, the amino acid X4may be substituted with a conservative amino acid (i.e., conservative to S and / or P). In some embodiments, the amino acid X4may be substituted with S, P, T, C, N, G, A, L, or V. The amino acid X5 may be substituted with any amino acid. In some embodiments, the amino acid Xs may be substituted with a conservative amino acid (i.e., conservative to L and / or N). In some embodiments, the amino acid X5may be substituted with L, N, I, V, M, A, F, Q, S, T, D, or H. The amino acid X6may be substituted with any amino acid. In some embodiments, the amino acid X6may be substituted with a conservative amino acid (i.e., conservative to Y and / or F). In some embodiments, the amino acid X6may be substituted with Y, F, W, H, S, T, L, M, I, or V. In some embodiments, the amino acid X6may be substituted with an aromatic amino acid (e.g., F, Y, W, H). The amino acid X7may be substituted with any amino acid. In some embodiments, the amino acid X7may be substituted with a conservative amino acid (i.e., conservative to D). In some embodiments, the amino acid X7may be substituted with D, E, N, or S. In some embodiments, the amino acid X7may be substituted with a negatively charged amino acid (e.g., D, E). The amino acid X8may be substituted with any amino acid. In some embodiments, the amino acid X8may be substituted with a conservative amino acid (i.e., conservative to V and / or A). In some embodiments, the amino acid X8may be substituted with V, A, G, S, L, I, or M. In some embodiments, the amino acid X8may be substituted with a nonpolar amino acid (e.g., A, G, I, L, M, F, P, W, V). In some embodiments, an anti- KIR2DL1 / KIR2DL2 / KIR2DL3 / KIR2DS1 / KIR2DS2 agent comprises a CDRL1 comprising the polypeptide QXIVSX2D where Xi is S or D and X2is N or T. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to S and / or D). In some embodiments, the amino acid Xi may be substituted with S, D, T, C, N, G, or E. The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to N and / or T). In some embodiments, the amino acid X2may be substituted with N, T, Q, S, D, H, C, or A. In some embodiments, the amino acid X2may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). In some embodiments, an anti- KIR2DL1 / KIR2DL2 / KIR2DL3 / KIR2DS1 / KIR2DS2 agent comprises a CDRL2 comprising the polypeptide XiAS where Xi is Y or W. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to Y and / or W). In some embodiments, the amino acid Xi may be substituted with Y, W, F, H, S, T, L, or M. In some embodiments, the amino acid Xi may be substituted with an aromatic amino acid (e.g., F, Y, W, H). In some embodiments, an anti- KIR2DL1 / KIR2DL2 / KIR2DL3 / KIR2DS1 / KIR2DS2 agent comprises a CDRL3 comprising the polypeptide QQXIX2SX3PX4T where Xi is D or H, X2is Y or F, X3is S or T, and X4is P or W. The amino acid Xi may be substituted with any amino acid. In some embodiments, the amino acid Xi may be substituted with a conservative amino acid (i.e., conservative to D and / or H). In some embodiments, the amino acid Xi may be substituted with D, H, K, R, N, Q, Y, W, E, or S. The amino acid X2may be substituted with any amino acid. In some embodiments, the amino acid X2may be substituted with a conservative amino acid (i.e., conservative to Y and / or F). In some embodiments, the amino acid X2may be substituted with Y, F, W, H, S, T, L, M, I, or V. In some embodiments, the amino acid X2may be substituted with an aromatic amino acid (e.g., F, Y, W, H). The amino acid X3may be substituted with any amino acid. In some embodiments, the amino acid X3may be substituted with a conservative amino acid (i.e., conservative to S and / or T). In some embodiments, the amino acid X3may be substituted with S, T, C, N, A, or G. In some embodiments, the amino acid X3may be substituted with a polar, uncharged amino acid (e.g., S, T, N, Q, Y, C). The amino acid X4may be substituted with any amino acid. In some embodiments, the amino acid X4may be substituted with a conservative amino acid (i.e., conservative to P and / or W). In some embodiments, the amino acid X4may be substituted with P, W, F, Y, H, L, M, A, G, or V. In some embodiments, the amino acid X4may be substituted with a nonpolar amino acid (e.g., A, G, I, L, M, F, P, W, V).

[0078] In some embodiments, an anti-KIR agent provided herein comprises an immunoglobulin heavy chain variable domain comprising an immunoglobulin heavy chain variable domain polypeptide provided in Table 3, or a polypeptide that is at least 80 percent identical to an immunoglobulin heavy chain variable domain polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises an immunoglobulin heavy chain variable domain comprising an immunoglobulin heavy chain variable domain polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises an immunoglobulin heavy chain variable domain comprising a polypeptide that is at least 90 percent identical to an immunoglobulin heavy chain variable domain polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises an immunoglobulin heavy chain variable domain comprising a polypeptide that is at least 95 percent identical to an immunoglobulin heavy chain variable domain polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises an immunoglobulin heavy chain variable domain comprising a polypeptide that is 100 percent identical to an immunoglobulin heavy chain variable domain polypeptide provided in Table 3.

[0079] In some embodiments, an anti-KIR agent provided herein comprises an immunoglobulin light chain variable domain comprising an immunoglobulin light chain variable domain polypeptide provided in Table 3, or a polypeptide that is at least 80 percent identical to an immunoglobulin light chain variable domain polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises an immunoglobulin light chain variable domain comprising a polypeptide that is at least 85 percent identical to an immunoglobulin light chain variable domain polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises an immunoglobulin light chain variable domain comprising a polypeptide that is at least 90 percent identical to an immunoglobulin light chain variable domain polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises an immunoglobulin light chain variable domain comprising a polypeptide that is at least 95 percent identical to an immunoglobulin light chain variable domain polypeptide provided in Table 3. In some embodiments, the anti-KIR agent provided herein comprises an immunoglobulin light chain variable domain comprising a polypeptide that is at least 100 percent identical to an immunoglobulin light chain variable domain polypeptide provided in Table 3.

[0080] Percent amino acid sequence identity with respect to a reference VH, VL, and CDR polypeptide sequences herein generally refers to the percentage of amino acid residues in a candidate sequence that are identical with the amino acid residues in the reference polypeptide sequence, after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent sequence identity, and not considering any conservative substitutions as part of the sequence identity. Alignment for purposes of determining percent amino acid sequence identity can be achieved in various ways that are within the skill in the art, for instance, using publicly available computer software such as BLAST, BLAST-2, ALIGN or Megalign (DNASTAR) software.

[0081] CDR sets

[0082] In some embodiments, an anti-KIR agent comprises an immunoglobulin heavy chain variable domain comprising a set of CDRs (i.e., CDRH1 , CDRH2, CDRH3); and an immunoglobulin light chain variable domain comprising a set of CDRs (i.e., CDRL1 , CDRL2, CDRL3). In some embodiments, an anti-KIR agent herein comprises two immunoglobulin heavy chain variable domains each comprising a set of CDRs (i.e., CDRH1 , CDRH2, CDRH3); and two immunoglobulin light chain variable domains each comprising a set of CDRs (i.e., CDRL1 , CDRL2, CDRL3). Sets of CDRs may comprise any combination of CDR amino acid sequences (i.e., CDRH1 , CDRH2, CDRH3; and CDRL1 , CDRL2, CDRL3) provided herein. In some embodiments, an immunoglobulin heavy chain variable domain comprises a set of CDRH1 , CDRH2, and CDRH3 amino acid sequences, and an immunoglobulin light chain variable domain comprises a set of CDRL1 , CDRL2, and CDRL3 amino acid sequences chosen from the sets provided in Table 3 herein. For an anti- KIR agent comprising two immunoglobulin heavy chain variable domains and two immunoglobulin light chain variable domains, each immunoglobulin heavy chain variable domain may comprise a set of CDRH1 , CDRH2, and CDRH3 amino acid sequences, and each immunoglobulin light chain variable domain may comprise a set of CDRL1 , CDRL2, and CDRL3 amino acid sequences chosen from the sets provided in Table 3.

[0083] In some embodiments, all CDRs are from the same set. For example, for an anti-KIR agent comprising two immunoglobulin heavy chain variable domains and two immunoglobulin light chain variable domains, each immunoglobulin heavy chain variable domain may comprise a set of CDRH1 , CDRH2, and CDRH3 amino acid sequences from a single clone in Table 3, and each immunoglobulin light chain variable domain may comprise a set of CDRL1 , CDRL2, and CDRL3 amino acid sequences from the same clone in Table 3.

[0084] In some embodiments, CDRs are from the different sets. For example, for an anti-KIR agent comprising two immunoglobulin heavy chain variable domains and two immunoglobulin light chain variable domains, each immunoglobulin heavy chain variable domain may comprise a set of CDRH1 , CDRH2, and CDRH3 amino acid sequences from a first clone in Table 3, and each immunoglobulin light chain variable domain may comprise a set of CDRL1 , CDRL2, and CDRL3 amino acid sequences from a second clone Table 3. In another example, for an anti-KIR agent comprising two immunoglobulin heavy chain variable domains and two immunoglobulin light chain variable domains, one immunoglobulin heavy chain variable domain may comprise a set of CDRH1 , CDRH2, and CDRH3 amino acid sequences from a first clone in Table 3 and the other immunoglobulin heavy chain variable domain may comprise a set of CDRH1 , CDRH2, and CDRH3 amino acid sequences from a second clone Table 3; and one immunoglobulin light chain variable domain may comprise a set of CDRL1 , CDRL2, and CDRL3 amino acid sequences from a first clone in Table 3 and the other immunoglobulin light chain variable domain may comprise a set of CDRL1 , CDRL2, and CDRL3 amino acid sequences from a second clone in Table 3. Competitor agents

[0085] Provided herein are anti-KIR agents that competitively bind, or are capable of competitively binding, with one or more anti-KIR agents described herein. In particular, provided herein are anti-KIR agents that compete, or are capable of competing, with one or more anti-KIR agents described herein for binding to KIR (e.g., KIR2DL1 , KIR2DL2, KIR2DL3, KIR2DL4, KIR2DL5, KIR2DS1 , KIR2DS2, KIR2DS4, KIR2DS5, KIR3DL1 , KIR3DL2, and / or KIR3DL3). Such agents that compete, or are capable of competing, with anti-KIR agents described herein may be referred to as competitor agents. In certain instances, an agent (i.e. , competitor agent) may be considered to compete for binding to KIR when the competitor binds to the same general region of KIR as an anti- KIR agent described herein. In certain instances, an agent (i.e., competitor agent) may be considered to compete for binding to KIR when the competitor binds to the exact same region of KIR as an anti-KIR agent described herein (e.g., exact same peptide (linear epitope) or exact same surface amino acids (conformational epitope)). In certain instances, an agent (i.e., competitor agent) may be considered capable of competing for binding to KIR when the competitor binds to the same general region of KIR as an anti-KIR agent described herein under suitable assay conditions. In certain instances, an agent (i.e., competitor agent) may be considered capable of competing for binding to KIR when the competitor binds to the exact same region of KIR as an anti- KIR agent described herein (e.g., exact same peptide (linear epitope) or exact same surface amino acids (conformational epitope)) under suitable assay conditions.

[0086] In certain instances, an agent (i.e., competitor agent) may be considered to compete for binding to KIR (e.g., KIR2DL1 , KIR2DL2, KIR2DL3, KIR2DL4, KIR2DL5, KIR2DS1 , KIR2DS2, KIR2DS4, KIR2DS5, KIR3DL1 , KIR3DL2, and / or KIR3DL3) when the competitor blocks the binding of one or more anti-KIR agents described herein to KIR. In certain instances, an agent (i.e., competitor agent) may be considered capable of competing for binding to KIR when the competitor blocks the binding of one or more anti-KIR agents described herein to KIR under suitable assay conditions. Whether a competitor blocks the binding of one or more anti-KIR agents described herein to KIR may be determined using a suitable competition assay or blocking assay, such as, for example, a blocking assay as described in Example 4 herein. A competitor agent may block binding of one or more anti-KIR agents described herein to KIR in a competition or blocking assay by 50% or more, and conversely, one or more anti-KIR agents described herein may block binding of the competitor agent to KIR in a competition or blocking assay by about 50% or more. For example, an agent (i.e., competitor agent) may block binding of one or more anti-KIR agents described herein to KIR in a competition or blocking assay by about 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 100%, and conversely, one or more anti-KIR agents described herein may block binding of the competitor agent to KIR in a competition or blocking assay by about 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 100%.

[0087] In certain instances, an agent (i.e., competitor agent) may be considered to compete for binding to KIR (e.g., KIR2DL1 , KIR2DL2, KIR2DL3, KIR2DL4, KIR2DL5, KIR2DS1 , KIR2DS2, KIR2DS4, KIR2DS5, KIR3DL1 , KIR3DL2, and / or KIR3DL3) when the competitor binds to KIR with a similar affinity as one or more anti-KIR agents described herein. In certain instances, an agent (i.e., competitor agent) may be considered capable of competing for binding to KIR when the competitor binds to KIR with a similar affinity as one or more anti-KIR agents described herein under suitable assay conditions. In some embodiments, an agent (i.e., competitor agent) is considered to compete for binding to KIR when the competitor binds to KIR with an affinity that is at least about 50% of the affinity of one or more anti-KIR agents described herein. For example, an agent (i.e., competitor agent) may be considered to compete for binding to KIR when the competitor binds to KIR with an affinity that is at least about 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 100% of the affinity of one or more anti-KIR agents described herein. A competitor agent may comprise any feature described herein for anti-KIR agents.

[0088] Also provided herein are anti-KIR agents that bind to, or are capable of binding to, the same epitope as one or more anti-KIR agents described herein. In particular, provided herein are anti-KIR agents that compete with one or more anti-KIR agents described herein for binding to the same epitope on KIR (e.g., an epitope on KIR2DL1 , KIR2DL2, KIR2DL3, KIR2DL4, KIR2DL5, KIR2DS1 , KIR2DS2, KIR2DS4, KIR2DS5, KIR3DL1 , KIR3DL2, and / or KIR3DL3). Such agents that bind the same epitope may be referred to as epitope competitors. In certain instances, an epitope competitor may bind to the exact same region of KIR as an anti-KIR agent described herein (e.g., exact same peptide (linear epitope) or exact same surface amino acids (conformational epitope)). In certain instances, an epitope competitor blocks the binding of one or more anti-KIR agents described herein to KIR. An epitope competitor may block binding of one or more anti-KIR agents described herein to KIR in a competition assay by about 50% or more, and conversely, one or more anti-KIR agents described herein may block binding of the epitope competitor to KIR in a competition assay by 50% or more. In certain instances, an epitope competitor binds to KIR with a similar affinity as one or more anti-KIR agents described herein. In some embodiments, an epitope competitor binds to KIR with an affinity that is at least about 50% of the affinity of one or more anti- KIR agents described herein. For example, an epitope competitor may bind to KIR with an affinity that is at least about 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 100% of the affinity of one or more anti-KIR agents described herein. An epitope competitor may comprise any feature described herein for anti-KIR agents. Antibodies

[0089] In some embodiments, an anti-KIR agent is a KIR binding antibody or antigen binding fragment thereof (e.g., a KIR2DL1 , KIR2DL2, KIR2DL3, KIR2DL4, KIR2DL5, KIR2DS1 , KIR2DS2, KIR2DS4, KIR2DS5, KIR3DL1 , KIR3DL2, and / or KIR3DL3 binding antibody or antigen binding fragment thereof). An antibody as described herein generally includes of one or more polypeptides substantially encoded by immunoglobulin genes or fragments of immunoglobulin genes. Immunoglobulin genes generally include kappa, lambda, alpha, gamma, delta, epsilon and mu constant region genes, as well as immunoglobulin variable region genes. Light chains are classified as either kappa or lambda. Heavy chains are classified as gamma, mu, alpha, delta, or epsilon, which in turn define the immunoglobulin classes, IgG, IgM, IgA, IgD and IgE, respectively. An antibody herein may be classified as IgG (e.g., lgG1 , lgG2, lgG3, lgG4), IgM, IgA, IgD, or IgE.

[0090] An antibody may be monoclonal. A monoclonal antibody generally refers to an antibody obtained from a population of substantially homogeneous antibodies, i.e., the individual antibodies comprising the population are identical (as assessed at the level of Ig heavy and / or light chain amino acid sequence) and / or bind the same epitope, except for possible variant antibodies, e.g., containing naturally occurring mutations or arising during production of a monoclonal antibody preparation, such variants generally being present in minor amounts. In contrast to polyclonal antibody preparations, which typically include different antibodies directed against different determinants (epitopes), each monoclonal antibody of a monoclonal antibody preparation is directed against a single determinant on an antigen. Thus, the modifier monoclonal indicates the character of the antibody as being obtained from a substantially homogeneous population of antibodies, and is not to be construed as requiring production of the antibody by any particular method. For example, the monoclonal antibodies to be used in accordance with the present technology may be made by a variety of techniques, including, but not limited to, hybridoma methods, recombinant DNA methods, phage-display methods, and methods utilizing transgenic animals containing all or part of the human immunoglobulin loci.

[0091] An antibody structural unit may be in the form of a tetramer. Each tetramer is composed of two identical pairs of polypeptide chains, each pair having one light chain (about 25 kD) and one heavy chain (about 50-70 kD). The N-terminus of each chain defines a variable region of about 100 to 1 10 or more amino acids primarily responsible for antigen recognition. The terms variable light chain (VL) and variable heavy chain (VH) refer to these light and heavy chains respectively.

[0092] Antibodies typically include one or more variable regions or variable domains, which refer to portions of light and heavy chains of an antibody that include amino acid sequences of complementarity determining regions (CDRs, e.g., CDRH1 , CDRH2, CDRH3, CDRL1 , CDRL2, and CDRL3) and framework regions (FRs). The variable domain for heavy chains and light chains is commonly designated VH and VL, respectively. The variable domain is included on Fab, F(ab’)2, Fv and scFv antigen binding fragments, for example, and is involved in specific antigen recognition. A complementarity determining region (CDR) refers to the three hypervariable regions in each chain that interrupt the four framework regions established by the light and heavy chain variable regions. The CDRs are primarily responsible for binding to an epitope of an antigen. The CDRs of each chain are typically referred to as CDR1 , CDR2, and CDR3, numbered sequentially starting from the N-terminus, and are also typically identified by the chain in which the particular CDR is located. Thus, a VH CDR3 is located in the variable domain of the heavy chain of the antibody in which it is found, whereas a VL CDR1 is the CDR1 from the variable domain of the light chain of the antibody in which it is found. The sequences of the framework regions of different light or heavy chains are relatively conserved within a species. The framework region of an antibody, that is the combined framework regions of the constituent light and heavy chains, serves to position and align the CDRs in three-dimensional space.

[0093] Antibodies typically have a heavy chain variable domain comprising an amino acid sequence represented by the formula: FRH1 -CDRH1 -FRH2-CDRH2-FRH3-CDRH3-FRH4, where FRH1 -4 represent the four heavy chain framework regions and CDRH1 -3 represent the three hypervariable regions of an antibody variable heavy domain. In some embodiments, FRH1 -4 are derived from a consensus sequence (for example the most common amino acids of a class, subclass or subgroup of heavy or light chains of human immunoglobulins) or are derived from an individual human antibody framework region or from a combination of different framework region sequences.

[0094] Antibodies also typically have a light chain variable domain comprising an amino acid sequence represented by the formula: FRL1 -CDRL1 -FRL2-CDRL2-FRL3-CDRL3-FRL4, where FRL1-4 represent the four framework regions and CDRL1 -3 represent the three hypervariable regions of an antibody variable light domain. In some embodiments, FRL1-4 are derived from a consensus sequence (for example the most common amino acids of a class, subclass or subgroup of heavy or light chains of human immunoglobulins) or are derived from an individual human antibody framework region or from a combination of different framework region sequences.

[0095] In some embodiments, an antibody is monovalent (an antibody with one antigen binding site). In some embodiments, an antibody is bivalent (an antibody with two antigen binding sites). In some embodiments, an antibody is in a multivalent form, e.g., a trivalent (an antibody with three antigen binding sites) or tetravalent form (an antibody with four antigen binding sites). In some embodiments, an antibody is monospecific (binds to one antigen or epitope). In some embodiments, an antibody is multi-specific (binds to more than one antigen or epitope; e.g., bispecific, trispecific, and the like).

[0096] Anti-KIR antibodies herein may include VH-VL dimers, including single chain antibodies (antibodies that exist as a single polypeptide chain), such as single chain Fv antibodies (sFv or scFv) in which a variable heavy and a variable light domain are joined together (directly or through a peptide linker) to form a continuous polypeptide. A single chain Fv antibody typically is a covalently linked VH-VL which may be expressed from a nucleic acid including VH- and VL- encoding sequences either joined directly or joined by a peptide-encoding linker. While the VH and VL are connected to each other as a single polypeptide chain, the VH and VL domains typically associate non- covalently. VH and VL domains together typically include six complementarity determining regions (CDR) (three in each from the heavy and light chain) that contribute amino acid residues for antigen binding and confer antigen binding specificity to the antibody. In certain instances, a single variable domain (or half of an Fv comprising only three CDRs specific for an antigen) has the ability to recognize and bind antigen. A dsFv is an Fv with an engineered intermolecular disulfide bond, which stabilizes the VH-VL pair.

[0097] Anti-KIR antibodies herein may include antigen binding fragments produced by the modification of whole antibodies. For example, pepsin digests an antibody C-terminal to the disulfide linkages in the hinge region to produce F(ab)'2, a dimer of Fab which itself is a light chain joined to VH-CH1 by a disulfide bond. The F(ab)'2 may be reduced under mild conditions to break the disulfide linkage in the hinge region thereby converting the (Fab')2 dimer into a Fab' monomer. The Fab' monomer is essentially a Fab with part of the hinge region. While various antigen binding fragments are defined in terms of the digestion of an intact antibody, antigen binding fragments may be synthesized de novo either chemically or by utilizing recombinant DNA methodology. Thus, an antibody may refer to antigen binding fragments either produced by the modification of whole antibodies or synthesized using recombinant DNA methodologies.

[0098] Anti-KIR antibodies herein may include antibody fragments or antigen binding fragments thereof that retain binding specificity. An antibody fragment or antigen binging fragment thereof may include a portion of an intact antibody (e.g., an antigen binding region of the intact antibody and / or a variable region of the intact antibody). Antibody fragments or antigen binding fragments thereof include but are not limited to Fv fragments, disulf ide-linked Fvs (dsFv), Fab fragments, Fab' fragments, and F(ab')2 fragments as described above. Antibody fragments or antigen binding fragments thereof also include but are not limited to Fd fragments (i.e. , a fragment of an antibody containing a variable domain (VH) and one constant region domain (CHI) of an antibody heavy chain), Fd' fragments (i.e., a fragment of an antibody containing one heavy chain portion of a F(ab')2 fragment), diabodies (i.e., dimeric scFvs), linear antibodies, and single-chain antibody molecules (e.g., single-chain Fvs (scFv) or single-chain Fabs (scFab)).

[0099] In some embodiments, an anti-KIR antibody or antigen binding fragment thereof is a chimeric antibody. Chimeric antibodies may include immunoglobulin molecules in which the constant region, or a portion thereof, is altered, replaced or exchanged so that the antigen binding site (variable region) is linked to a constant region of a different or altered class, effector function and / or species, or an entirely different molecule which confers new properties to the chimeric antibody, e.g., an enzyme, toxin, hormone, growth factor, drug, and the like. Chimeric antibodies may also include immunoglobulin molecules in which the variable region, or a portion thereof, is altered, replaced or exchanged with a variable region, or portion thereof, having a different or altered antigen specificity; or with corresponding sequences from another species or from another antibody class or subclass.

[0100] In some embodiments, an anti-KIR antibody or antigen binding fragment thereof comprises one or more human framework regions. In some embodiments, an anti-KIR antibody or antigen binding fragment thereof is humanized. Humanized antibodies generally refer to immunoglobulin molecules in which CDRs from a donor antibody (e.g., mouse, rabbit) are grafted onto human framework sequences. Humanized antibodies also may include residues of donor origin in the framework sequences. A humanized antibody also may include at least a portion of a human immunoglobulin constant region. Humanized antibodies also may include residues which are found neither in the recipient antibody nor in the imported CDR or framework sequences. Humanization can be performed using methods known in the art.

[0101] In some embodiments, an anti-KIR antibody or antigen binding fragment thereof comprises one or more variations (e.g., amino acid substitutions, deletions, and / or insertions), An example method for identification of certain residues or regions of an antibody that are preferred locations for amino acid substitutions is alanine scanning mutagenesis. Here, a residue or group of target residues are identified (e.g., charged residues such as arg, asp, his, lys, and glu) and replaced by a neutral or negatively charged amino acid (most preferably alanine or polyalanine) to affect the interaction of the amino acids with an antigen. Those amino acid locations demonstrating functional sensitivity to the substitutions then are refined by introducing further or other variants at, or for, the sites of substitution. Thus, while the site for introducing an amino acid sequence variation is predetermined, the nature of the mutation per se need not be predetermined. For example, to analyze the performance of a mutation at a given site, alanine scanning or random mutagenesis is conducted at a target codon or region and the expressed antibody variants may be screened for the desired activity. Amino acid sequence insertions may include amino-terminal and / or carboxyl-terminal fusions ranging in length from one residue to polypeptides containing a hundred or more residues, as well as intra-sequence insertions of single or multiple amino acid residues. Examples of terminal insertions include an N-terminal methionyl residue or the antibody fused to an epitope tag. Other insertional variants include the fusion of an enzyme or a polypeptide that increases the serum halflife of the antibody to the N- or C-terminus of the antibody.

[0102] Sites for amino acid substitutions may include sites in the hypervariable regions and may include sites in the framework regions. Amino acid substitutions may include conservative substitutions or non-conservative substitutions. Examples of substitutions are listed below.

[0103] Ala (A): val; leu; ile

[0104] Arg (R): lys; gin; asn

[0105] Asn (N): gin; his; asp, lys; arg

[0106] Asp (D): glu; asn Cys (C): ser; ala Gin (Q): asn; glu Glu (E): asp; gin Gly (G): ala His (H): asn; gin; lys; arg Ile (I): leu; val; met; ala; phe; norleucine Leu (L): norleucine; ile; val; met; ala; phe Lys (K): arg; gin; asn Met (M): leu; phe; ile Phe (F): leu; val; ile; ala; tyr Pro (P): ala Ser (S): thr Thr (T): ser Trp (W): tyr; phe Tyr (Y): trp; phe; thr; ser Val (V): ile; leu; met; phe; ala; norleucine

[0107] Substantial modifications in the biological properties of an antibody may be accomplished by selecting substitutions that differ significantly in their effect on maintaining (a) the structure of the polypeptide backbone in the area of the substitution, for example, as a sheet or helical conformation, (b) the charge or hydrophobicity of the molecule at the target site, or (c) the bulk of the side chain.

[0108] Naturally occurring residues can be divided into groups based on common side-chain properties listed below. (1 ) hydrophobic: norleucine, met, ala, val, leu, ile;

[0109] (2) neutral hydrophilic: cys, ser, thr;

[0110] (3) acidic: asp, glu;

[0111] (4) basic: asn, gin, his, lys, arg;

[0112] (5) residues that influence chain orientation: gly, pro; and

[0113] (6) aromatic: trp, tyr, phe.

[0114] Non-conservative substitutions generally entail exchanging a member of one of these classes for another class.

[0115] Any cysteine residue not involved in maintaining the proper conformation of an antibody also may be substituted, e.g., to improve the oxidative stability of the molecule and prevent aberrant crosslinking. Conversely, cysteine bond(s) may be added to the antibody to improve its stability (e.g., where the antibody is an antibody fragment such as an Fv fragment).

[0116] One type of substitutional variant involves substituting one or more hypervariable region residues of a parent antibody (e.g. a humanized or human antibody). Generally, the resulting variant(s) selected for further development will have improved biological properties relative to the parent antibody from which they are generated. A convenient way for generating such substitutional variants is affinity maturation using phage display. Briefly, several hypervariable region sites (e.g. 6-7 sites) are mutated to generate all possible amino substitutions at each site. The antibody variants thus generated are displayed in a monovalent fashion from filamentous phage particles as fusions to the gene III product of M13 packaged within each particle. The phage-displayed variants are then screened for their biological activity (e.g. binding affinity). In order to identify candidate hypervariable region sites for modification, alanine-scanning mutagenesis can be performed to identify hypervariable region residues contributing significantly to antigen binding. Alternatively, or in addition, it may be beneficial to analyze a crystal structure of the antigen-antibody complex to identify contact points between the antibody and antigen. Such contact residues and neighboring residues are candidates for substitution. Once such variants are generated, the panel of variants is subjected to screening and antibodies with superior properties in one or more relevant assays may be selected for further development.

[0117] Another type of amino acid variant of an antibody alters the original glycosylation pattern of the antibody. For example, one or more carbohydrate moieties found in the antibody may be deleted, and / or one or more glycosylation sites that are not present in the antibody may be added. Glycosylation of antibodies is typically either N-linked and / or or O-linked. N-linked refers to the attachment of a carbohydrate moiety to the side chain of an asparagine residue. The tripeptide sequences asparagine-X-serine and asparagine-X-threonine, where X is any amino acid except proline, are the most common recognition sequences for enzymatic attachment of a carbohydrate moiety to an asparagine side chain. Thus, the presence of either of these tripeptide sequences in a polypeptide creates a potential glycosylation site. O-linked glycosylation refers to the attachment of one of the sugars N-acetylgalactosamine, galactose, or xylose to a hydroxyamino acid, most commonly serine or threonine, although 5-hydroxyproline or 5-hydroxylysine may also be used. Addition of glycosylation sites to an antibody may be accomplished by altering the amino acid sequence such that it contains one or more of the above-described tripeptide sequences (for N- linked glycosylation sites). The alteration may also be made by the addition of, or substitution by, one or more serine or threonine residues to the sequence of an original antibody (for O-linked glycosylation sites).

[0118] Fc polypeptide

[0119] In some embodiments, an antibody or antigen binding fragment thereof comprises a fragment crystallizable region (Fc region), also referred to as an Fc polypeptide. An Fc polypeptide is part of each of the two heavy chains in the antibody and can interact with certain cell surface receptors and certain components of the complement system. An Fc polypeptide typically includes the CH2 domain and the CH3 domain, which are immunoglobulin constant region domain polypeptides. In some embodiments, the Fc polypeptide in an antibody described herein can be a wild-type Fc polypeptide, e.g., a human lgG1 Fc polypeptide. In certain embodiments, an antibody described herein can comprise a wild-type Fc polypeptide having the following sequence:

[0120] APELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQ YNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKN QVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSC SVMHEALHNHYTQKSLSLSPGK (SEQ ID NO: 1).

[0121] In come embodiments, an antibody or antigen binding fragment thereof comprises a variant of the wild-type Fc polypeptide that has at least 90% (e.g., 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 99.5%) identity to the sequence of a wild-type Fc polypeptide (e.g., SEQ ID NO: 1) and at least one amino acid substitution relative to the sequence of a wild-type Fc polypeptide (e.g., SEQ ID NO: 1 ).

[0122] In some embodiments, an Fc polypeptide includes one or more modifications (e.g., one or more amino acid substitutions, insertions, or deletions relative to a comparable wild-type Fc region). Antibodies comprising modified Fc polypeptides typically have altered phenotypes relative to antibodies comprising wild-type Fc polypeptides. For example, antibodies comprising modified Fc polypeptides can have altered serum half-life, altered stability, altered susceptibility to cellular enzymes, and / or altered effector function (e.g., as assayed in an NK-dependent or macrophagedependent assay).

[0123] In some embodiments, an Fc polypeptide in an antibody or antigen binding fragment thereof can include amino acid substitutions that modulate effector function. In certain embodiments, an Fc polypeptide in an antibody described herein can include amino acid substitutions that reduce or eliminate effector function. Illustrative Fc polypeptide amino acid substitutions that reduce effector function include, but are not limited to, substitutions in a CH2 domain, e.g., at positions 4 and 5 (position numbering relative to the sequence of SEQ ID NO: 1). For example, in some embodiments, one or both Fc polypeptides in an antibody described herein can comprise L4A and L5A substitutions.

[0124] Additional Fc polypeptide amino acid substitutions that modulate an effector function include, e.g., substitution at position 99 (position numbering relative to the sequence of SEQ ID NO: 1 ). For example, in some embodiments, one or both Fc polypeptides in an antibody described herein can comprise a P99G substitution. In certain embodiments, one or both Fc polypeptides in an antibody described herein can have L4A, L5A, and P99G substitutions.

[0125] In some embodiments, an Fc polypeptide includes one or more modifications that alter (relative to a wild-type Fc polypeptide) the Ratio of Affinities of the modified Fc polypeptide to an activating FcvR (such as FcvRIlA or FcvRIIIA) relative to an inhibiting FcvR (such as FcvRHB):

[0126] Ratio of Affinities = WT to variant change in affinity to FevRactivating WT to variant change in affinity to FcvRinhibiting

[0127] Where a modified Fc polypeptide has a Ratio of Affinities greater than 1 , an antibody herein may have particular use in providing a therapeutic or prophylactic treatment of a disease, disorder, or infection, or the amelioration of a symptom thereof, where an enhanced efficacy of effector cell function mediated by FcvR is desired, e.g., cancer or infectious disease. Where a modified Fc region has a Ratio of Affinities less than 1 , an antibody herein may have particular use in providing a therapeutic or prophylactic treatment of a disease or disorder, or the amelioration of a symptom thereof, where a decreased efficacy of effector cell function mediated by FcvR is desired, e.g., autoimmune or inflammatory disorders. The following are examples of single, double, triple, quadruple, and quintuple amino acid substitutions in an Fc polypeptide that provide a Ratio of Affinities greater than 1 or less than 1 .

[0128]

[0129] Antigens

[0130] An antibody may bind to one or more antigens. An antigen generally refers to a molecule, compound, or complex that is recognized by an antibody, i.e., can be specifically bound by the antibody. The term antigen may be used interchangeably with immunogen, antibody target, target analyte, and the like. An antigen may refer to any molecule that can be specifically recognized by an antibody, e.g., a polypeptide, polynucleotide, carbohydrate, lipid, chemical moiety, or combinations thereof (e.g., phosphorylated or glycosylated polypeptides, etc.). The term antigen does not necessarily indicate that the molecule is immunogenic in every context, but generally indicates that it can be targeted by an antibody.

[0131] Antibodies typically bind to an epitope on an antigen. An epitope is the localized site on an antigen that is recognized and bound by an antibody. Epitopes can include a few amino acids or portions of a few amino acids, e.g., 5 or 6, or more, e.g., 20 or more amino acids, or portions of those amino acids. In some cases, the epitope includes non-protein components, e.g., from a carbohydrate, nucleic acid, or lipid. In some cases, the epitope is a three-dimensional moiety. Thus, for example, where the target is a protein, the epitope can be comprised of consecutive amino acids, or amino acids from different parts of the protein that are brought into proximity by protein folding (e.g., a discontinuous epitope). The same is true for other types of target molecules that form three- dimensional structures. An epitope typically includes at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, or at least 9 amino acids in a unique spatial conformation. In certain instances, an epitope includes 8-10 amino acids in a unique spatial conformation. Methods of determining spatial conformation of epitopes include, for example, x-ray crystallography and 2-dimensional nuclear magnetic resonance.

[0132] The terms specific for, specifically binds, and like terms generally refer to a molecule (e.g., antibody or antigen binding fragment) that binds to a target with at least 2-fold greater affinity than non-target compounds, e.g., at least any of 4-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold, 20-fold, 25-fold, 50-fold, or 100-fold greater affinity. For example, an antibody that specifically binds a target will typically bind the target with at least a 2-fold greater affinity than a non-target. Specificity can be determined using standard methods, e.g., solid-phase ELISA immunoassays. The term binds with respect to an antibody target (e.g., antigen, analyte, immune complex), typically indicates that an antibody binds a majority of the antibody targets in a pure population (assuming appropriate molar ratios). For example, an antibody that binds a given antibody target typically binds to at least about 2 / 3 of the antibody targets in a solution (e.g., at least about 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% of the antibody targets in a solution).

[0133] Modified agents / antibodies

[0134] In some embodiments, an agent / antibody comprises one or more modifications. For example, immunoconjugates comprising an antibody described herein may be conjugated to a cytotoxic agent such as a toxin (e.g., an enzymatically active toxin of bacterial, fungal, plant or animal origin, or fragments thereof), a radioactive isotope (for example, a radioconjugate), or a cytotoxic drug. Such conjugates are sometimes referred to as antibody-drug conjugates or ADCs. Conjugates can be made using any suitable bifunctional protein coupling agent such as N-succinimidyl-3-(2- pyridyldithiol) propionate (SPDP), iminothiolane (IT), bifunctional derivatives of imidoesters (such as dimethyl adipimidate HCL), active esters (such as disuccinimidyl suberate), aldehydes (such as glutaraldehyde), bis-azido compounds (such as bis-(p-azidobenzoyl)hexanediamine), bis- diazonium derivatives (such as bis-(p-diazoniumbenzoyl)-ethylenediamine), diisocyanates (such as tolyene 2,6-diisocyanate), and bis-active fluorine compounds (such as 1 ,5-difluoro-2,4- dinitrobenzene).

[0135] In some embodiments, an agent / antibody disclosed herein may be formulated as an immunoliposome. Liposomes containing an antibody may be prepared by a suitable method known in the art. Liposomes with enhanced circulation time may be generated. For example, liposomes can be generated by a reverse phase evaporation method with a lipid composition comprising phosphatidylcholine, cholesterol, and PEG-derivatized phosphatidylethanolamine (PEG-PE). Liposomes may be extruded through filters of defined pore size to yield liposomes with a desired diameter. Fab' fragments of an antibody provided herein may be conjugated to the liposomes via a disulfide interchange reaction, for example. Other active ingredients may be contained within the liposome.

[0136] In some embodiments, enzymes or other polypeptides may be covalently bound to an agent / antibody disclosed herein by a suitable technique such as the use of the heterobifunctional cross-linking reagents. In some embodiments, fusion proteins comprising at least the antigen binding region of an antibody provided herein linked to at least a functionally active portion of an enzyme can be constructed using recombinant DNA techniques. In certain embodiments, it may be desirable to use an antigen binding fragment, rather than an intact antibody, to increase penetration of target tissues and cells, for example. In such instances, it may be desirable to modify the antigen binding fragment in order to increase its serum half-life. This may be achieved, for example, by incorporation of a salvage receptor binding epitope into the antigen binding fragment (e.g., by mutation of the appropriate region in the antigen binding fragment or by incorporating the epitope into a peptide tag that is then fused to the antigen binding fragment at either end or in the middle, e.g., by DNA or peptide synthesis.

[0137] In some embodiments, an antibody or antigen binding fragment thereof comprises, is conjugated to, or is hybridized to one or more oligonucleotides. In some embodiments, the oligonucleotide contains a barcode sequence (e.g., a sample barcode sequence). In some embodiments, the oligonucleotide further contains a binding site for a primer and / or an anchor. In some embodiments, a detectable marker or label (e.g., a radioisotope or fluorophore) is conjugated to the oligonucleotide. In some embodiments, the oligonucleotide is a polymeric sequence. The terms oligonucleotide and polynucleotide are used interchangeably to refer to a single-stranded multimer of nucleotides from about 2 to about 500 nucleotides in length. Oligonucleotides may be synthetic, made enzymatically (e.g., via polymerization), or using a “split-pool” method. Oligonucleotides may include ribonucleotide monomers (i.e., can be oligoribonucleotides) and / or deoxyribonucleotide monomers (i.e., oligodeoxyribonucleotides). Oligonucleotides may include a combination of both deoxyribonucleotide monomers and ribonucleotide monomers in the oligonucleotide (e.g., random or ordered combination of deoxyribonucleotide monomers and ribonucleotide monomers). Oligonucleotides may include one or more functional moieties that are attached (e.g., covalently or non-covalently) to another structure.

[0138] An anchor generally refers to a polymer, e.g., a polynucleotide or oligonucleotide, which is designed to hybridize to a complementary oligonucleotide sequence. In some embodiments, an anchor is designed for the purpose of generating a double stranded construct oligonucleotide sequence. In some embodiments, an anchor is positioned at the 3’ end of the construct oligonucleotide sequence. In some embodiments, an anchor is positioned at the 5’ end of a construct oligonucleotide sequence. Each anchor may be specific for its intended complementary sequence.

[0139] In some embodiments, a binding site for a primer is a functional component of the oligonucleotide which itself is an oligonucleotide or polynucleotide sequence that provides an annealing site for amplification of the oligonucleotide. A binding site for a primer can be formed of polymers of DNA, RNA, PNA, modified bases or combinations of these bases, or polyamides, etc. In some embodiments, a binding site for a primer is about 10 of such monomeric components, e.g., nucleotide bases, in length. In some embodiments, a binding site for a primer is at least about 5 to 100 monomeric components, e.g., nucleotides, in length. In certain embodiments, a binding site for a primer can be a generic sequence suitable as an annealing site for a variety of amplification technologies. Amplification technologies include, but are not limited to, DNA-polymerase based amplification systems, such as polymerase chain reaction (PCR), real-time PCR, loop mediated isothermal amplification (LAMP, MALBAC), strand displacement amplification (SDA), multiple displacement amplification (MDA), recombinase polymerase amplification (RPA) and polymerization by any number of DNA polymerases (for example, T4 DNA polymerase, Sulfulobus DNA polymerase, Klenow DNA polymerase, Bst polymerase, Phi29 polymerase) and RNA- polymerase based amplification systems (such as T7-, T3-, and SP6-RNA-polymerase amplification), nucleic acid sequence based amplification (NASBA), self-sustained sequence replication (3SR), rolling circle amplification (RCA), ligase chain reaction (LCR), helicase dependent amplification (I), ramification amplification method, and RNA-seq.

[0140] In some embodiments, a modification is introduced into an antibody (e.g., within the polypeptide chain or at either the N- or C-terminal), e.g., to extend in vivo half-life, such as PEGylation or incorporation of long-chain polyethylene glycol polymers (PEG). Introduction of PEG or long chain polymers of PEG increases the effective molecular weight of polypeptides, for example, to prevent rapid filtration into the urine. In some embodiments, a lysine residue in a sequence is conjugated to PEG directly or through a linker. Such linker can be, for example, a Glu residue or an acyl residue containing a thiol functional group for linkage to the appropriately modified PEG chain. An alternative method for introducing a PEG chain is to first introduce a Cys residue at the C-terminus or at solvent exposed residues such as replacements for Arg or Lys residues. This Cys residue is then site-specifically attached to a PEG chain containing, for example, a maleimide function. Methods for incorporating PEG or long chain polymers of PEG are known in the art.

[0141] Covalent modifications of an antibody are also included within the scope of this technology. For example, modifications may be made by chemical synthesis or by enzymatic or chemical cleavage of an antibody. Other types of covalent modifications of an antibody are introduced into the molecule by reacting targeted amino acid residues of the antibody with an organic derivatizing agent that is capable of reacting with selected side chains or the N- or C- terminal residues. An example covalent modification of an antibody involves linking the antibody to one of a variety of non-proteinaceous polymers, e.g., polyethylene glycol, polypropylene glycol, or polyoxyalkylenes.

[0142] Labels and solid supports

[0143] In some embodiments, an anti-KIR agent / antibody comprises a detectable marker or label. In some embodiments, an anti-KIR agent / antibody is conjugated to a detectable marker or label. For example, for research and diagnostic applications, an anti-KIR agent / antibody may be labeled with a detectable moiety. Any suitable marker, label, or moiety may be associated with or conjugated to an anti-KIR agent / antibody herein. In some embodiments, an anti-KIR agent / antibody is labeled with one or more radioisotopes such as, for example,35S,14C,125l,3H, and1311. The antibody can be labeled with the radioisotope using techniques known in the art, and radioactivity can be measured using scintillation counting, for example. In some embodiments, an anti-KIR agent / antibody is labeled with one or more fluorescent labels such as, for example, rare earth chelates (europium chelates), fluorescein and its derivatives, rhodamine and its derivatives, dansyl, Lissamine, phycoerythrin, Texas Red and Brilliant Violet™. Fluorescent labels may be conjugated to an antibody using methods known in the art. Fluorescence can be quantified using a flow cytometer, imaging microscope, or fluorimeter, for example.

[0144] In some embodiments, an anti-KIR agent / antibody is labeled with one or more enzyme-substrate labels. An enzyme can catalyze a chemical alteration of a chromogenic substrate that can be measured using various techniques. For example, an enzyme may catalyze a color change in a substrate, which can be measured spectrophotometrically. Alternatively, an enzyme may alter the fluorescence or chemiluminescence of a substrate. Techniques for quantifying a change in fluorescence are known in the art. For example, a chemiluminescent substrate becomes electronically excited by a chemical reaction and may then emit light that can be measured (using a chemilluminometer, for example) or donates energy to a fluorescent acceptor. Examples of enzymatic labels include luciferases (e.g., firefly luciferase and bacterial luciferase), luciferin, 2,3- dihydrophthalazinediones, malate dehydrogenase, urease, peroxidase such as horseradish peroxidase (HRPO), alkaline phosphatase, beta-galactosidase, glucoamylase, lysozyme, saccharide oxidases (e.g., glucose oxidase, galactose oxidase, and glucose-6-phosphate dehydrogenase), heterocyclicoxidases (such as uricase and xanthine oxidase), lactoperoxidase, microperoxidase, and the like. Techniques for conjugating enzymes to antibodies known in the art.

[0145] In certain instances, a label is indirectly conjugated with the agent / antibody. For example, an antibody can be conjugated with biotin and any of the labels described above can be conjugated with avidin, or vice versa. Biotin binds selectively to avidin and thus, the label can be conjugated with the antibody in this indirect manner. Alternatively, to achieve indirect conjugation of a label with an antibody, the antibody may be conjugated with a small hapten (e.g., digoxin) and a label described above can be conjugated with an anti-hapten antibody (e.g., anti-digoxin antibody). Thus, indirect conjugation of a label with an antibody can be achieved.

[0146] In some embodiments, an anti-KIR agent / antibody need not be labeled, and the presence thereof can be detected, e.g., using a labeled antibody which binds to an anti-KIR antibody. In some embodiments, an anti-KIR agent / antibody herein is immobilized on a solid support or substrate. In some embodiments, an anti-KIR agent / antibody herein is non-diffusively immobilized on a solid support (e.g., the anti-KIR agent / antibody does not detach from the solid support). A solid support or substrate can be any physically separable solid to which an anti-KIR agent / antibody can be directly or indirectly attached including, but not limited to, surfaces provided by microarrays and wells, and particles such as beads (e.g., paramagnetic beads, magnetic beads, microbeads, nanobeads), microparticles, and nanoparticles. Solid supports also can include, for example, chips, columns, optical fibers, wipes, filters (e.g., flat surface filters), one or more capillaries, glass and modified or functionalized glass (e.g., controlled-pore glass (CPG)), quartz, mica, diazotized membranes (paper or nylon), polyformaldehyde, cellulose, cellulose acetate, paper, ceramics, metals, metalloids, semiconductive materials, quantum dots, coated beads or particles, other chromatographic materials, magnetic particles; plastics (including acrylics, polystyrene, copolymers of styrene or other materials, polybutylene, polyurethanes, TEFLON™, polyethylene, polypropylene, polyamide, polyester, polyvinylidenedifluoride (PVDF), and the like), polysaccharides, nylon or nitrocellulose, resins, silica or silica-based materials including silicon, silica gel, and modified silicon, Sephadex®, Sepharose®, carbon, metals (e.g., steel, gold, silver, aluminum, silicon and copper), inorganic glasses, conducting polymers (including polymers such as polypyrole and polyindole); micro or nanostructured surfaces such as nucleic acid tiling arrays, nanotube, nanowire, or nanoparticulate decorated surfaces; or porous surfaces or gels such as methacrylates, acrylamides, sugar polymers, cellulose, silicates, or other fibrous or stranded polymers. In some embodiments, the solid support or substrate may be coated using passive or chemically-derivatized coatings with any number of materials, including polymers, such as dextrans, acrylamides, gelatins or agarose. Beads and / or particles may be free or in connection with one another (e.g., sintered). In some embodiments, a solid support or substrate can be a collection of particles. In some embodiments, the particles can comprise silica, and the silica may comprise silica dioxide. In some embodiments the silica can be porous, and in certain embodiments the silica can be non-porous. In some embodiments, the particles further comprise an agent that confers a paramagnetic property to the particles. In certain embodiments, the agent comprises a metal, and in certain embodiments the agent is a metal oxide, (e.g., iron or iron oxides, where the iron oxide contains a mixture of Fe2+and Fe3+). An anti-KIR agent / antibody may be linked to a solid support by covalent bonds or by non-covalent interactions and may be linked to a solid support directly or indirectly (e.g., via an intermediary agent such as a spacer molecule or biotin). Nucleic acids, vectors, host cells, and recombinant methods

[0147] Provided herein are isolated nucleic acids encoding an anti-KIR agent (e.g., anti-KIR antibody), vectors and host cells comprising the nucleic acid, and recombinant techniques for the production of the agent or antibody.

[0148] Provided herein are nucleic acids (e.g., isolated nucleic acids) comprising a nucleotide sequence that encodes an anti-KIR agent or antibody, or fragment thereof. In some embodiments, a nucleic acid encodes an immunoglobulin heavy chain variable domain of an anti-KIR agent provided herein. In some embodiments, a nucleic acid encodes an immunoglobulin light chain variable domain of an anti-KIR agent provided herein. In some embodiments, a nucleic acid encodes an immunoglobulin heavy chain variable domain and an immunoglobulin light chain variable domain of an anti-KIR agent provided herein. In some embodiments, a nucleic acid comprises a nucleotide sequence provided in Table 3. In some embodiments, a nucleic acid comprises a nucleotide sequence that encodes an amino acid sequence provided in Table 3. For example, a nucleic acid may comprise a nucleotide sequence that encodes a CDR amino acid sequence of any one the CDRs provided in Table 3. A nucleic acid may comprise a nucleotide sequence that encodes an immunoglobulin heavy chain variable domain amino acid sequence of any one of the immunoglobulin heavy chain variable domains provided in Table 3. A nucleic acid may comprise a nucleotide sequence that encodes an immunoglobulin light chain variable domain amino acid sequence of any one of the immunoglobulin light chain variable domains provided in Table 3.

[0149] For recombinant production of an anti-KIR agent or antibody, a nucleic acid encoding the anti-KIR agent or antibody may be isolated and inserted into a replicable vector for further cloning and / or expression. In certain instances, an anti-KIR agent or antibody may be produced by homologous recombination. DNA encoding an anti-KIR agent or antibody can be readily isolated and sequenced using conventional procedures (e.g., by using oligonucleotide probes that are capable of binding specifically to genes encoding the heavy and light chains of the antibody). Any suitable vector may be used. Vector components generally include, but are not limited to, one or more of a signal sequence, an origin of replication, one or more marker genes, an enhancer element, a promoter, and a transcription termination sequence.

[0150] Suitable host cells for cloning and / or expressing DNA in vectors include prokaryote cells, yeast cells, and higher eukaryote cells. Suitable prokaryotes for this purpose include eubacteria, such as Gram-negative or Gram-positive organisms, for example, Enterobacteriaceae such as Escherichia, e.g., E. coli, Enterobacter, Erwinia, Klebsiella, Proteus, Salmonella, e.g., Salmonella typhimurium, Serratia, e.g., Serratia marcescans, and Shigella, as well as Bacilli such as B. subtilis and B. licheniformis, Pseudomonas such as P. aeruginosa, and Streptomyces. In certain instances, eukaryotic microbes such as filamentous fungi or yeast are suitable cloning and / or expression hosts for anti-KIR agent / antibody-encoding vectors. Saccharomyces cerevisiae, or common baker's yeast, is commonly used among lower eukaryotic host microorganisms. A number of other genera, species, and strains are commonly available and useful herein, such as Schizosaccharomyces pombe; Kluyveromyces hosts such as, e.g., K. lactis, K. fragilis (ATCC 12,424), K. bulgaricus (ATCC 16,045), K. wickeramii (ATCC 24, 178), K. waltii (ATCC 56,500), K. drosophilarum (ATCC 36,906), K. thermotolerans, and K. marxianus; yarrowia (EP 402,226); Pichia pastoris (EP 183,070); Candida; Trichoderma reesia (EP 244,234); Neurospora crassa; Schwanniomyces such as Schwanniomyces occidentalis; and filamentous fungi such as, e.g., Neurospora, Penicillium, Tolypocladium, and Aspergillus hosts such as A. nidulans and A. niger.

[0151] Suitable host cells for expression of anti-KIR agents / antibodies may be derived from multicellular organisms. Examples of invertebrate cells include plant and insect cells. Numerous baculoviral strains and variants and corresponding permissive insect host cells from hosts such as Spodoptera frugiperda (caterpillar), Aedes aegypti (mosquito), Aedes albopictus (mosquito), Drosophila melanogaster (fruit fly), and Bombyx mori (silk moth) have been identified. A variety of viral strains for transfection are publicly available, e.g., the L-1 variant of Autographa californica NPV and the Bm-5 strain of Bombyx mori NPV. Plant cell cultures of cotton, corn, potato, soybean, petunia, tomato, and tobacco can also be utilized as hosts.

[0152] Suitable host cells for expression of anti-KIR agents / antibodies also may include vertebrate cells (e.g., mammalian cells). Vertebrate cells may be propagated in culture (tissue culture). Examples of useful mammalian host cell lines include monkey kidney CV1 line transformed by SV40 (COS-7, ATCC CRL 1651 ); human embryonic kidney line (293 or 293 cells subcloned for growth in suspension culture); baby hamster kidney cells (BHK, ATCC CCL 10); Chinese hamster ovary cells / -DHFR (CHO); mouse Sertoli cells (TM4); monkey kidney cells (CV1 ATCC CCL 70); African green monkey kidney cells (VERO-76, ATCC CRL-1587); human cervical carcinoma cells (HELA, ATCC CCL 2); canine kidney cells (MDCK, ATCC CCL 34); buffalo rat liver cells (BRL 3A, ATCC CRL 1442); human lung cells (W138, ATCC CCL 75); human liver cells (Hep G2, HB 8065); mouse mammary tumor (MMT 060562, ATCC CCL51 ); TRI cells; MRC 5 cells; FS4 cells; and a human hepatoma line (Hep G2).

[0153] Host cells may be transformed with the above-described expression or cloning vectors for antibody production and cultured in conventional nutrient media modified as appropriate for inducing promoters, selecting transformants, and / or amplifying the genes encoding the desired sequences. Host cells used to produce an agent / antibody herein may be cultured in a variety of media. Commercially available media such as Ham's F10 (Sigma), Minimal Essential Medium ((MEM), Sigma), RPMI-1640 (Sigma), and Dulbecco's Modified Eagle's Medium ((DMEM), Sigma) are suitable for culturing the host cells. Any of these media may be supplemented as necessary with hormones and / or other growth factors (such as insulin, transferrin, or epidermal growth factor), salts (such as sodium chloride, calcium, magnesium, and phosphate), buffers (such as HEPES), nucleotides (such as adenosine and thymidine), antibiotics (such as GENT MYCIN™), trace elements (defined as inorganic compounds usually present at final concentrations in the micromolar range), and glucose or an equivalent energy source. Any other necessary supplements may also be included at appropriate concentrations that would be known to those skilled in the art. Certain culture conditions, such as temperature, pH, and the like, may include conditions previously used with the host cell selected for expression.

[0154] When using recombinant techniques, an agent / antibody can be produced intracellularly, in the periplasmic space, or directly secreted into the medium. If the antibody is produced intracellularly, as a first step, the particulate debris, either host cells or lysed fragments, is removed, for example, by centrifugation or ultrafiltration. The agent / antibody composition prepared from the cells can be purified using, for example, hydroxylapatite chromatography, gel electrophoresis, dialysis, and affinity chromatography, with affinity chromatography being the preferred purification technique. Protein A can be used to purify antibodies that are based on human heavy chains. The suitability of protein A as an affinity ligand depends on the species and isotype of any immunoglobulin Fc domain that is present in the antibody. Protein G may be for mouse isotypes and for human g3. Other techniques for protein purification, such as fractionation on an ion-exchange column, ethanol precipitation, Reverse Phase HPLC, chromatography on silica, chromatography on heparin SEPHAROSE™, chromatography on an anion or cation exchange resin (such as a polyaspartic acid column), chromatofocusing, SDS-PAGE, and ammonium sulfate precipitation are also available depending on the antibody to be recovered.

[0155] Pharmaceutical formulations, dosing, and routes of administration

[0156] Provided herein are therapeutic compositions comprising an anti-KIR agent / antibody described herein, and a pharmaceutically acceptable excipient. Provided herein are antibodies and related compositions, which may be useful for blocking KIR ligand binding, for example. In some embodiments, provided herein are antibodies and related compositions, which may be useful for enhancing KIR ligand binding. In some embodiments, provided herein are antibodies and related compositions, which may be useful for inhibiting natural killer cell activity. In some embodiments, provided herein are antibodies and related compositions, which may be useful for activating natural killer cell activity. Serum KIR levels may be associated with prognosis in patients with certain diseases or disorders. Accordingly, anti-KIR antibodies may be useful for detecting KIR levels in certain patients.

[0157] In some embodiments, an anti-KIR antibody or antigen binding fragment thereof may be formulated in a pharmaceutical composition that is useful for a variety of purposes, including the treatment of diseases or disorders. Pharmaceutical compositions comprising one or more antibodies may be administered using a pharmaceutical device to a patient in need thereof, and according to one embodiment of the technology, kits are provided that include such devices. Such devices and kits may be designed for routine administration, including self-administration, of the pharmaceutical compositions herein.

[0158] Provided herein are therapeutic compositions comprising an anti-KIR agent / antibody described herein and a pharmaceutically acceptable carrier, excipient, or stabilizer. Therapeutic formulations of an anti-KIR antibody may be prepared for storage by mixing the agent or antibody having the desired degree of purity with physiologically and / or pharmaceutically acceptable carriers, excipients, or stabilizers, in the form of lyophilized formulations or aqueous solutions. Acceptable carriers, excipients, or stabilizers are nontoxic to recipients at the dosages and concentrations employed, and include buffers such as phosphate, citrate, and other organic acids; antioxidants including ascorbic acid and methionine; preservatives (such as octadecyldimethylbenzyl ammonium chloride; hexamethonium chloride; benzalkonium chloride, benzethonium chloride; phenol, butyl or benzyl alcohol; alkyl parabens such as methyl or propyl paraben; catechol; resorcinol; cyclohexanol; 3-pentanol; and m-cresol); low molecular weight (less than about 10 residues) polypeptides; proteins, such as serum albumin, gelatin, or immunoglobulins; hydrophilic polymers such as polyvinylpyrrolidone; amino acids such as glycine, glutamine, asparagine, histidine, arginine, or lysine; monosaccharides, disaccharides, and other carbohydrates including glucose, mannose, or dextrins; chelating agents such as EDTA; sugars such as sucrose, mannitol, trehalose or sorbitol; salt-forming counter-ions such as sodium; metal complexes (e.g., Zn-protein complexes); and / or non-ionic surfactants such as TWEEN™, PLURONICS™, or polyethylene glycol (PEG).

[0159] Formulations herein may also contain more than one active compound as necessary for the particular indication being treated, preferably those with complementary activities that do not adversely affect each other. Such molecules are suitably present in combination in amounts that are effective for the purpose intended. Formulations for in vivo administration generally are sterile. This may be accomplished for instance by filtration through sterile filtration membranes, for example. Sustained-release preparations may be prepared. Suitable examples of sustained-release preparations include semipermeable matrices of solid hydrophobic polymers containing the agent / antibody, which matrices are in the form of shaped articles, e.g., films, or microcapsule. Examples of sustained-release matrices include polyesters, hydrogels (for example, poly(2- hydroxyethyl-methacrylate), or poly (vinyl alcohol)), polylactides, copolymers of L-glutamic acid and gamma ethyl-L-glutamate, non-degradable ethylene-vinyl acetate, degradable lactic acid-glycolic acid copolymers such as the Lupron Depot® (injectable microspheres composed of lactic acid- glycolic acid copolymer and leuprolide acetate), and poly-D-(-)-3-hydroxybutyric acid. While polymers such as such as ethylene-vinyl acetate and lactic acid-glycolic acid enable release of molecules for over 100 days, certain hydrogels release proteins for shorter time periods.

[0160] For therapeutic applications, antibodies provided herein may be administered to a mammal, e.g., a human, in a pharmaceutically acceptable dosage form such as those discussed above, including those that may be administered to a human intravenously as a bolus or by continuous infusion over a period of time, or by intramuscular, intraperitoneal, intra-cerebrospinal, subcutaneous, intraarticular, intrasynovial, intrathecal, oral, topical, or inhalation routes. For the prevention or treatment of disease, the appropriate dosage of agent or antibody will depend on the type of disease to be treated, the severity and course of the disease, whether the antibody is administered for preventative or therapeutic purposes, previous therapy, the patient’s clinical history and response to the antibody, and the discretion of the health professional. The antibody may be suitably administered to the patient at one time or over a series of treatments.

[0161] Depending on the type and severity of the disease, about 1 pg / kg to about 50 mg / kg (e.g., 0.1 -20 mg / kg) of antibody may be an initial candidate dosage for administration to the patient, whether, for example, by one or more separate administrations, or by continuous infusion. A typical daily or weekly dosage might range from about 1 pg / kg to about 20 mg / kg or more, depending on the factors mentioned above. For repeated administrations over several days or longer, depending on the condition, the treatment may be repeated until a desired suppression of disease symptoms occurs. However, other dosage regimens may be useful. The progress of this therapy is easily monitored by conventional techniques and assays, including, for example, radiographic imaging. Detection methods using the antibody to determine KIR levels in bodily fluids or tissues may be used in order to optimize patient exposure to the therapeutic antibody.

[0162] In some embodiments, a composition comprising an antibody herein can be administered as a monotherapy, and in some embodiments, the composition comprising the antibody can be administered as part of a combination therapy. Accordingly, provided herein are therapeutic compositions where the anti-KIR agent / antibody is used as an adjuvant or in conjunction with an adjuvant. In some cases, the effectiveness of the antibody in preventing or treating diseases may be improved by administering the antibody serially or in combination with another drug that is effective for those purposes, such as a chemotherapeutic drug for treatment of cancer or a microbial infection. In other cases, the antibody may serve to enhance or sensitize cells to chemotherapeutic treatment, thus permitting efficacy at lower doses and with lower toxicity. Certain combination therapies include, in addition to administration of the composition comprising an antibody that blocks KIR activity, delivering a second therapeutic regimen selected from the group consisting of a chemotherapeutic agent, radiation therapy, surgery, and a combination of any of the foregoing. Such other agents may be present in the composition being administered or may be administered separately. Also, the antibody may be suitably administered serially or in combination with the other agent or modality, e.g., chemotherapeutic drug or radiation for treatment of cancer, infection, and the like, or an immunosuppressive drug.

[0163] Research and diagnostic

[0164] Provided herein are diagnostic reagents comprising anti-KIR agent / antibody described herein. For example, antibodies provided herein may be used to detect and / or purify KIR from bodily fluid(s) or tissues. Anti-KIR antibodies, for example, may be useful in diagnostic assays for KIR, e.g., detecting its presence in specific cells, tissues, or bodily fluids. Such diagnostic methods may be useful in diagnosis of a disease or disorder. Also provided herein are methods for detecting KIR and / or measuring KIR levels in a subject or in a sample from a subject. For example, a method may comprise contacting a sample (e.g., a biological sample known or suspected to contain KIR) with an antibody provided herein, and, if the sample contains KIR, detecting KIR:antibody complexes. In some embodiments, a KIR detection method is performed in vitro. In some embodiments, a KIR detection method is performed in vivo. For in vivo diagnostic assays, the antibody may be labeled with a radionuclide (such as111In, "Tc,14C,1311,125l,3H,32P, or35S) so that the bound target molecule can be localized using immunoscintillography.

[0165] Also provided herein are reagents comprising anti-KIR agent / antibody described herein for nondiagnostic use. Also provided herein are reagents comprising anti-KIR agent / antibody described herein for non-therapeutic use. Also provided herein are reagents comprising anti-KIR agent / antibody described herein for non-diagnostic and non-therapeutic use. For example, provided herein are reagents comprising an anti-KIR agent / antibody described herein for use in research applications. Research applications may include investigating KIR and its role in immune cell function and / or regulation (e.g., natural killer cell function and / or regulation, T lymphocyte function and / or regulation), cell signaling, signal transduction, disease, infection, inflammation, and the like. Also provided herein are methods for detecting KIR and / or measuring KIR levels in a non- biological sample. For example, a method may comprise contacting a non-biological sample (e.g., a laboratory research sample known or suspected to contain KIR) with an antibody provided herein, and, if the sample contains KIR, detecting KIR:antibody complexes. Laboratory research samples may include non-human animal models, samples from non-human animal models, cell lines, products produced by cell lines, and the like.

[0166] Anti-KIR agents and antibodies provided herein may be employed in any suitable detection assay, such as flow cytometry, immunohistochemistry, immunofluorescence, mass cytometry, competitive binding assays, direct and indirect sandwich assays, and immunoprecipitation assays.

[0167] Flow cytometry and mass cytometry assays generally involve the use of a single primary antibody to specifically identify the presence of the target molecule expressed on the surface of a dispersed suspension of individual cells. The dispersed cells are typically obtained from a biological fluid sample, e.g., blood, but may also be obtained from a dispersion of single cells prepared from a solid tissue sample such as a tumor biopsy. The primary antibody may be directly conjugated with a detectable moiety, e.g., a fluorophore such as phycoerythrin for flow cytometry or a heavy metal chelate for mass cytometry. Alternatively, the primary antibody may be unlabeled or labeled with an undetectable tag such as biotin, and the primary antibody is then detected by a detectably labeled secondary antibody that specifically recognizes the primary antibody itself or the tag on the primary antibody. The labeled cells are then analyzed in an instrument capable of single cell detection, e.g., flow cytometer, mass cytometer, fluorescence microscope or brightfield light microscope, to identify those individual cells in the dispersed population or tissue sample that express the target recognized by the primary antibody. In certain instances, fixed and permeabilized cells may be used.

[0168] Sandwich assays involve the use of two antibodies, each capable of binding to a different immunogenic portion, or epitope, of the protein that is detected. In a sandwich assay, the test sample analyte is bound by a first antibody that is immobilized on a solid support, and thereafter a second antibody binds to the analyte, thus forming an insoluble three-part complex. The second antibody may itself be labeled with a detectable moiety (direct sandwich assays) or may be measured using an anti-immunoglobulin antibody that is labeled with a detectable moiety (indirect sandwich assay). For example, one type of sandwich assay is an ELISA assay, in which case the detectable moiety is an enzyme. In a cell ELISA, the target cell population may be attached to the solid support using antibodies first attached to the support and that recognize different cell surface proteins. These first antibodies capture the cells to the support. In certain instances, fixed and permeabilized cells may be used. In some embodiments, an agent / antibody provided herein is formulated for immunohistochemical analysis. In some embodiments, immunohistochemical analysis includes the use of samples. In some embodiments, immunohistochemical analysis includes the use of blood and / or tissue samples. A sample may be fresh or frozen or may be embedded in paraffin and fixed with a preservative such as formalin. In some embodiments, a sample is a formalin-fixed paraffin- embedded (FFPE) sample. In some embodiments, an FFPE sample is saturated with formalin (i.e. formaldehyde) and then embedded in a block of paraffin wax. In some embodiments, an FFPE sample is stable at room temperature. In some embodiments, all or most of the structures in an FFPE sample are preserved. In some embodiments, the intracellular and surface proteins in an FFPE sample are preserved. In some embodiments, mRNA in an FFPE sample is preserved. In some embodiments, mRNA, intracellular proteins, and surface proteins in an FFPE sample are preserved. In some embodiments, surface proteins in an FFPE sample are denatured.

[0169] In some embodiments, an anti-KIR antibody or antigen binding fragment thereof provided herein is capable of detecting KIR in a formalin-fixed paraffin-embedded sample. In some embodiments, an anti-KIR antibody or antigen binding fragment thereof provided herein is capable of detecting KIR on the surface of a formalin-fixed paraffin-embedded sample. In some embodiments, an anti-KIR antibody or antigen binding fragment thereof provided herein is capable of detecting intracellular KIR in a formalin-fixed paraffin-embedded sample. In some embodiments, an anti-KIR antibody or antigen binding fragment thereof provided herein is capable of detecting intracellular KIR and KIR on the surface of a formalin-fixed paraffin-embedded sample.

[0170] In some embodiments, a sample is a fresh sample that has been frozen. In some embodiments, a sample is a fresh sample that has been cryogenically frozen. In some embodiments, a sample is flash frozen. In some embodiments, a sample is flash frozen and stored at 80°C. In some embodiments, all or most of the structures in a flash frozen sample are preserved. In some embodiments, intracellular and surface proteins in a flash frozen sample are preserved. In some embodiments, mRNA in a flash frozen sample is preserved. In some embodiments, mRNA, intracellular proteins, and surface proteins in a flash frozen sample are preserved. In some embodiments, surface proteins in a flash frozen sample are denatured.

[0171] In some embodiments, an anti-KIR antibody or antigen binding fragment thereof provided herein is capable of detecting KIR in a frozen sample. In some embodiments, an anti-KIR antibody or antigen binding fragment thereof provided herein is capable of detecting KIR on the surface of a frozen sample. In some embodiments, an anti-KIR antibody or antigen binding fragment thereof provided herein is capable of detecting intracellular KIR in a frozen sample. In some embodiments, an anti-KIR antibody or antigen binding fragment thereof provided herein is capable of detecting intracellular KIR and KIR on the surface of a frozen sample.

[0172] Detection of KIR

[0173] Provided herein are antibodies and methods for detecting KIR (e.g., KIR2DL1 , KIR2DL2, KIR2DL3, KIR2DL4, KIR2DL5, KIR2DS1 , KIR2DS2, KIR2DS4, KIR2DS5, KIR3DL1 , KIR3DL2, and / or KIR3DL3). In some embodiments, antibodies and methods are provided for detecting KIR in a biological sample. In some embodiments, KIR is detected on the surface of a cell. In some embodiments, KIR is detected intracellularly. In some embodiments, detection of KIR is in vitro. In some embodiments, detection of KIR is in vivo.

[0174] In some embodiments, a biological sample is a solid tissue, fluid, or cell. Solid tissue samples may comprise solid tissue from one or more of adipose tissue, bladder, bone, brain, breast, cervix, endothelium, gallbladder, kidney, liver, lung, lymph, ovary, prostate, salivary gland, stomach, testis, thyroid, urethra, uterus, vagina, and vulva. Fluid samples may comprise one or more of amniotic fluid, bile, blood, breast milk, breast fluid, cerebrospinal fluid, lavage fluid, lymphatic fluid, mucous, plasma, saliva, semen, serum, spinal fluid, sputum, tears, umbilical cord blood, urine, and vaginal fluid.

[0175] In some embodiments, a sample comprises immune cells. In some embodiments, a sample comprises one or more immune cell chosen from macrophages, neutrophils, B cells, plasmacytoid dendritic cells (pDCs), lymphocytes, leukocytes, T cells, monocytes, myeloid dendritic cells (mDCs), innate lymphoid cells, mast cells, eosinophils, basophils, natural killer cells, and peripheral blood mononuclear cells (PBMCs). In some embodiments, a sample comprises non-immune cells. For example, a sample may comprise one or more of fibroblasts, vascular smooth muscle cells, endothelial cells, brain cells, and liver cells. In some embodiments, a sample comprises tumor cells.

[0176] In some embodiments, the biological sample is from a healthy subject. In some embodiments, the sample is from a subject with a disease or condition. In some embodiments, the detection of KIR indicates the presence or absence of a disease or disorder. In some embodiments, the disease or disorder is a cancer, an autoimmune disorder, an inflammatory disorder, a neurologic disorder, or an infection. In some embodiments, the disease or disorder is associated with KIR expression. In some embodiments, the disease or disorder is associated with aberrant KIR expression. In some embodiments, the disease or disorder is associated with immune cells. In some embodiments, the disease or disorder is associated with natural killer cells. In some embodiments, the disease or disorder is associated with T lymphocytes. Kits

[0177] Provided herein are kits comprising an anti-KIR agent / antibody described herein. A kit generally refers to a packaged combination of reagents in predetermined amounts with instructions for use (e.g., instructions for performing a diagnostic assay). In some embodiments, the kit is a diagnostic kit configured to detect KIR (e.g., KIR2DL1 , KIR2DL2, KIR2DL3, KIR2DL4, KIR2DL5, KIR2DS1 , KIR2DS2, KIR2DS4, KIR2DS5, KIR3DL1 , KIR3DL2, and / or KIR3DL3) in a sample (e.g., a biological sample). In some embodiments, the kit is a non-diagnostic kit configured to detect KIR (e.g., KIR2DL1 , KIR2DL2, KIR2DL3, KIR2DL4, KIR2DL5, KIR2DS1 , KIR2DS2, KIR2DS4, KIR2DS5, KIR3DL1 , KIR3DL2, and / or KIR3DL3) in a non-biological sample (e.g., a research sample). Where the anti-KIR agent is labeled with a fluorophore, the kit may include an identical isotype negative control irrelevant antibody to control for non-specific binding of the anti-KIR agent. Where the anti-KIR agent is labeled with an enzyme, the kit may include substrates and cofactors required by the enzyme (e.g., a substrate precursor which provides the detectable chromophore or fluorophore). In addition, other additives may be included such as stabilizers, buffers (e.g., a block buffer or lysis buffer) and the like. The relative amounts of the various reagents may be varied widely to provide for concentrations in solution of the reagents that substantially optimize the sensitivity of the assay. Particularly, the reagents may be provided as dry powders, usually lyophilized, including excipients that on dissolution will provide a reagent solution having the appropriate concentration.

[0178] Articles of Manufacture

[0179] Provided herein are articles of manufacture containing materials useful for the treatment, or diagnosis, of the disorders described above. An article of manufacture may comprise a container and a label. Suitable containers include, for example, bottles, vials, syringes, and test tubes. The containers may be formed from a variety of materials such as glass or plastic. The container holds a composition that is effective for treating the condition and may have a sterile access port (for example the container may be an intravenous solution bag or a vial having a stopper pierceable by a hypodermic injection needle). The active anti-KIR agent in the composition may be an anti-KIR antibody. The label on, or associated with, the container indicates that the composition is used for treating, or diagnosing, the condition of choice. The article of manufacture may further comprise a second container comprising a pharmaceutically acceptable buffer, such as phosphate-buffered saline, Ringer’s solution, or dextrose solution. It may further include other materials desirable from a commercial and user standpoint, including other buffers, diluents, filters, needles, syringes, and package inserts with instructions for use. Certain Implementations

[0180] Following are non-limiting examples of certain implementations of the technology.

[0181] A1 . An isolated antibody or antigen binding fragment thereof that binds one or more killer cell immunoglobulin-like receptors (KIRs) or a portion thereof, comprising:

[0182] (a) an immunoglobulin heavy chain variable domain comprising:

[0183] (i) a heavy chain complementarity determining region 1 (CDRH1 ) comprising a CDRH1 polypeptide provided in Table 3, or a polypeptide that is at least 80 percent identical to a CDRH1 polypeptide provided in Table 3;

[0184] (ii) a heavy chain complementarity determining region 2 (CDRH2) comprising a CDRH2 polypeptide provided in Table 3, or a polypeptide that is at least 80 percent identical to a CDRH2 polypeptide provided in Table 3; and

[0185] (iii) a heavy chain complementarity determining region 3 (CDRH3) comprising a CDRH3 polypeptide provided in Table 3, or a polypeptide that is at least 80 percent identical to a CDRH3 polypeptide provided in Table 3; and

[0186] (b) an immunoglobulin light chain variable domain comprising:

[0187] (i) a light chain complementarity determining region 1 (CDRL1 ) comprising a CDRL1 polypeptide provided in Table 3, or a polypeptide that is at least 80 percent identical to a CDRL1 polypeptide provided in Table 3;

[0188] (ii) a light chain complementarity determining region 2 (CDRL2) comprising a CDRL2 polypeptide provided in Table 3, or a polypeptide that is at least 80 percent identical to a CDRL2 polypeptide provided in Table 3; and

[0189] (iii) a light chain complementarity determining region 3 (CDRL3) comprising a CDRL3 polypeptide provided in Table 3, or a polypeptide that is at least 80 percent identical to a CDRL3 polypeptide provided in Table 3.

[0190] A1 .1 The isolated antibody or antigen binding fragment thereof of embodiment A1 , wherein the one or more KIRs are chosen from KIR2DL1 , KIR2DL2, KIR2DL3, KIR2DL4, KIR2DL5, KIR2DS1 , KIR2DS2, KIR2DS4, KIR2DS5, KIR3DL1 , KIR3DL2, and KIR3DL3.

[0191] A2. The isolated antibody or antigen binding fragment thereof of embodiment A1 or A1 .1 , wherein the immunoglobulin heavy chain variable domain comprises an immunoglobulin heavy chain variable domain polypeptide provided in Table 3, or a polypeptide that is at least 80 percent identical to an immunoglobulin heavy chain variable domain polypeptide provided in Table 3.

[0192] A3. The isolated antibody or antigen binding fragment thereof of any one of embodiments A1 to A2, wherein the immunoglobulin light chain variable domain comprises an immunoglobulin light chain variable domain polypeptide provided in Table 3, or a polypeptide that is at least 80 percent identical to an immunoglobulin light chain variable domain polypeptide provided in Table 3.

[0193] A4. The isolated antibody or antigen binding fragment thereof of any one of embodiments A1 -A3, comprising two immunoglobulin heavy chain variable domains and two immunoglobulin light chain variable domains.

[0194] A5. The isolated antibody or antigen binding fragment thereof of any one of embodiments A1 -A4, further comprising one or more human framework regions.

[0195] A6. The isolated antibody or antigen binding fragment thereof of any one of embodiments A1 -A5, wherein the antibody or antigen binding fragment thereof is humanized.

[0196] A7. The isolated antibody or antigen binding fragment thereof of any one of embodiments A1 -A6, wherein the antibody or antigen binding fragment thereof comprises or is conjugated to a detectable marker or label.

[0197] A8. The isolated antibody or antigen binding fragment thereof of embodiment A7, wherein the detectable marker or label comprises a detectable moiety.

[0198] A9. The isolated antibody or antigen binding fragment thereof of any one of embodiments A1 -A8, further comprising an oligonucleotide.

[0199] A10. The isolated antibody or antigen binding fragment thereof of any one of embodiments A1 -A9, wherein the antibody or antigen binding fragment thereof is immobilized on a solid support.

[0200] A11. The isolated antibody or antigen binding fragment thereof of any one of embodiments A1 -A10, wherein the antibody or antigen binding fragment thereof is non-diffusively immobilized on a solid support.

[0201] A12. The isolated antibody or antigen binding fragment thereof of any one of embodiments A1 -A11 , that is a single-chain fragment.

[0202] A13. The isolated antibody or antigen binding fragment thereof of embodiment A12, wherein the single-chain fragment is a single-chain variable fragment (scFv).

[0203] A14. The isolated antibody or antigen binding fragment thereof of any one of embodiments A1 -A13, for non-diagnostic use and / or non-therapeutic use.

[0204] B1 . A kit comprising the isolated antibody or antigen binding fragment thereof of any one of embodiments A1-A14, and instructions for use.

[0205] C1 . A diagnostic reagent comprising the isolated antibody or antigen binding fragment thereof of any one of embodiments A1 -A13. D1 . A diagnostic kit configured to detect KIR or a portion thereof in a biological sample, wherein the kit comprises the isolated antibody or antigen binding fragment thereof of any one of embodiments A1 -A13 or the diagnostic reagent of embodiment C1 .

[0206] E1 . A therapeutic composition comprising the isolated antibody or antigen binding fragment thereof of any one of embodiments A1 -A13, and a pharmaceutically acceptable excipient.

[0207] E2. The therapeutic composition of embodiment E1 , wherein the antibody or antigen binding fragment thereof is used as an adjuvant or in conjunction with an adjuvant.

[0208] F1. An isolated polynucleotide comprising a nucleic acid sequence that encodes the immunoglobulin heavy chain variable domain of any one of embodiments A1 -A13.

[0209] F2. A recombinant expression vector comprising the isolated polynucleotide of embodiment F1 .

[0210] F3. A host cell transfected with the recombinant expression vector of embodiment F2.

[0211] F4. An isolated polynucleotide comprising a nucleic acid sequence that encodes the immunoglobulin light chain variable domain of any one of embodiments A1-A13.

[0212] F5. A recombinant expression vector comprising the isolated polynucleotide of embodiment F4.

[0213] F6. A host cell transfected with the recombinant expression vector of embodiment F5.

[0214] F7. A recombinant expression vector comprising a first expression cassette and a second expression cassette, wherein the first expression cassette comprises a polynucleotide comprising a nucleic acid sequence that encodes the immunoglobulin heavy chain variable domain of any one of embodiments A1-A13, and the second expression cassette comprises a polynucleotide comprising a nucleic acid sequence that encodes the immunoglobulin light chain variable domain of any one of embodiments A1-A13.

[0215] F8. The recombinant expression vector of embodiment F7, wherein the first expression cassette and the second expression cassette each comprise a promoter.

[0216] F9. A host cell transfected with the recombinant expression vector of embodiment F7 or F8.

[0217] G1 . A method of detecting one or more killer cell immunoglobulin-like receptors (KIRs), comprising a) contacting a sample with the antibody or antigen binding fragment thereof of any one of embodiments A1 -A13, and b) if the sample contains one or more KIRs, detecting KI R:anti-KI R complexes.

[0218] G2. The method of embodiment G1 , wherein the one or more KIRs are chosen from KIR2DL1 , KIR2DL2, KIR2DL3, KIR2DL4, KIR2DL5, KIR2DS1 , KIR2DS2, KIR2DS4, KIR2DS5, KIR3DL1 , KIR3DL2, and KIR3DL3. G3. The method of embodiment G1 or G2, wherein the method is performed in vitro.

[0219] G3. The method of any one of embodiments G1 -G3, wherein the sample is a biological sample.

[0220] G4. The method of any one of embodiments G1 -G3, wherein the sample is a non-biological sample.

[0221] H1 . A first anti-KIR agent that binds one or more killer cell immunoglobulin-like receptors (KIRs), wherein the first agent competitively binds, or is capable of competitively binding, with a second anti-KIR agent, wherein the second agent is the antibody or antigen binding fragment thereof of any one of embodiments A1-A13.

[0222] H2. A first anti-KIR agent that binds one or more killer cell immunoglobulin-like receptors (KIRs), wherein the first agent binds to, or is capable of binding to, the same epitope as a second anti-KIR agent, wherein the second agent is the antibody or antigen binding fragment thereof of any one of embodiments A1-A13.

[0223] H3. An isolated antibody or antigen binding fragment thereof that binds one or more killer cell immunoglobulin-like receptors (KIRs) or a portion thereof, wherein the antibody or antigen binding fragment thereof blocks or is capable of blocking KIR ligand binding.

[0224] H4. An isolated antibody or antigen binding fragment thereof that binds one or more killer cell immunoglobulin-like receptors (KIRs) or a portion thereof, wherein the antibody or antigen binding fragment thereof enhances or is capable of enhancing KIR ligand binding.

[0225] H5. An isolated antibody or antigen binding fragment thereof that binds one or more killer cell immunoglobulin-like receptors (KIRs) or a portion thereof, wherein the antibody or antigen binding fragment thereof inhibits or is capable of inhibiting natural killer cell activity.

[0226] H6. An isolated antibody or antigen binding fragment thereof that binds one or more killer cell immunoglobulin-like receptors (KIRs) or a portion thereof, wherein the antibody or antigen binding fragment thereof activates or is capable of activating natural killer cell activity.

[0227] Examples

[0228] The examples set forth below illustrate certain implementations and do not limit the technology.

[0229] Example 1: Generation anti-KIR antibody expressing hybridomas

[0230] This Example describes the generation and characterization of hybridomas that secrete monoclonal antibodies that react with various KIR family members.

[0231] Briefly, animals were immunized with recombinant KIR proteins, with mouse myeloma cell lines expressing human KIR immunogens as shown in Table 2 below. Hybridomas were formed using standard protocols to fuse myeloma cells with spleens, and lymph node cells were drained and harvested. Successful fusions were selected into HAT medium, and cloned into approximately one cell per well in microtiter plates, after which culture supernatants were tested against KIR- expressing cell transfectants by flow cytometry. Wells were selected by assessment of staining profiles and then sub-cultured into larger vessels and sub-cloned.

[0232] Certain clones were selected for further analysis, as shown in Table 2 below. Amino acid and nucleic acid sequences for certain clones are provided in Table 3 below.

[0233] Example 2: Anti-KIR antibody function

[0234] Methods

[0235] The following methods were used to assess anti-KIR antibody function. Results are shown in Figs. 1 -152 and described below.

[0236] Cell culture

[0237] Ba / F3 murine interleukin-3 dependent pro-B cell line was cultured in RPMI with 10% Fetal Bovine Serum (FBS) + 1% Pen / Strep + 2 ng / mL Recombinant Mouse IL-3. K562 cells were cultured in RPMI + 10% FBS + 1% Pen / Strep at 37C. For isolating NK cells, briefly, peripheral blood mononuclear cells (PBMCs) were isolated from whole blood through LYMPHOPURE phase separation. NK cells were then purified from isolated PBMCs using MOJOSORT Human NK Cell Isolation Kit (Biolegend 480054). NK cells were then incubated in RPMI + 10% FBS + 1% Pen / Strep + 50 ng / mL human recombinant IL2 + 10 ng / mL human recombinant IL15 at 37eC for 16 hours before harvesting the day of experimentation.

[0238] Transfection of cell lines

[0239] Ba / F3 murine interleukin-3 dependent pro-B cell line was transfected using constructs coding for the extracellular domains of KIRs. The accession numbers for the KIR molecules are as follows: NM 014218.3, NM 014219.2, NM_015868.3, AF034771 .1 , NM001080770, NM_002255.6, NM 014512.1 , NM 012312.4, NM_012313.1 , NM_012314.6, NM_014513.2, NM_020535.3, NM 001018081.1 , NM 013289.3, NM_001322168.1 , NM_006737, NM_153443.5,

[0240] NM_001083539.2. Cells were maintained in RPMI with 10% Fetal Bovine Serum (FBS) and recombinant mouse interleukin-3.

[0241] Flow cytometry staining

[0242] Cells were stained according to flow cytometry staining protocols as noted on the BioLegend website. Briefly, fluorophore-conjugated antibodies were added to cell solutions at a noted mass per test concentration and incubated at room temperature for 15 minutes. Cells were then washed with fluorescence-activated cell sorting (FACS) buffer twice before assessing cells using flow cytometers. In the case of the use of non-conjugated antibodies, antibodies were added to cell solutions as previously described. Cells were then washed with FACS buffer twice before fluorophore-conjugated secondary species or isotype specific antibodies were added to cell solutions. Cells were then washed twice with FACS buffer before adding additional fluorophore- conjugated antibodies as co-stains and incubated at room temperature for 15 minutes. Cells were then washed with FACS buffer twice before analyzing on a flow cytometer.

[0243] Ligand binding assay

[0244] The ligands specific to particular KIR proteins were added to cells and incubated at room temperature for 15 minutes. For tagged recombinant protein ligands, the binding was detected by the anti-tag antibody. Cell suspension was then washed and analyzed on a flow cytometer. When determining antibody effects on ligand-KIR interactions, cells were first incubated with KIR-specific antibody for 15 minutes at room temperature before the addition of the ligand to the cell solution.

[0245] NK cytotoxicity assay

[0246] K562 cells were counted and washed with culture media on the day of harvest. K562 cells were then stained using TAG-IT VIOLET dye (BioLegend 425101 ) for 12 minutes. TAG-IT VIOLET dye reaction was then quenched using cold culture media and allowed to rest for 15 minutes. Cells were centrifuged and washed using culture media. NK cells were counted and washed with RPMI + 10% FBS + 1% Pen / Strep on the day of harvest before being resuspend in culture media. NK cells were the incubated with 10 pg of designated antibody or HLA protein for 15 minutes at 37eC to allow for adequate antibody to NK interaction.

[0247] Afterwards, Tag-it Violet stained K562 cells were then mixed at a 1 :1 ratio to NK cells and incubated at 37eC for 1 hour. NK-K562 cell co-culture was spun down and supernatant was removed for in-solution analyte analysis. NK-K562 cell co-culture was then stained using standard staining procedure.

[0248] Cytokine quantification assay

[0249] Cytokine quantification of NK-K562 culture supernatant was analyzed using Human CD8 / NK V02 Panel LEGENDPLEX Assay kit (BioLegend 741 187). A detailed procedure can be found on the BioLegend website and should be followed per manufacturer’s instructions. Briefly, co-culture media supernatant was stained using kit capture beads for 2 hours before being spun down and washed three times using LEGENDPLEX wash buffer. Capture beads were then stained using biotinylated analyte detection antibodies for 1 hour before adding PE-streptavidin to the detection antibodies and incubated for 30 minutes at room temperature. Analyte-stained beads were then spun down and washed three times with LEGENDPLEX wash buffer. Analyte beads were then run on a flow cytometer to collect analyte quantification data. Data was analyzed using LEGENDPLEX Software.

[0250] Functional results

[0251] KIR-specific antibodies disrupted or enhanced MHC class I or ligand interaction

[0252] Each member within the KIR protein family binds to a multitude of MHC class I proteins or certain other ligand proteins. To determine if the KIR protein-ligand interactions can be disrupted by each specific KIR-protein interaction, developed anti-KIR antibodies were added to singular KIR protein transfected Ba / F3 cell lines followed by singular KIR protein's known ligand. The ligand presence was then measured through a conjugate fluorophore or with anti-ligand antibody. Each tested KIR protein and the developed anti-KIR antibody’s effect on their KIR’s respective ligand interaction is detailed below.

[0253] KIR3DL3 (see e.g., Figs. 151-152) - The interaction between HHLA2 and KIR3DL3 transfected Ba / F3 was able to be completely disrupted by mAb S23011 A,B,C,D,E,F and S22010B. The mAb S22010G appeared to have no interaction but mAb S22010H appeared to increase the HHLA2’s interaction with KIR3DL3. KIR3DL2 (see e.g., Figs. 148-150) - While the interaction between HLA-A*11 :01 APC conjugated tetramer with bound P20 peptide and KIR3DL2 transfected Ba / F3 was initially minimal, the interaction of KIR3DL2 and its ligand was increased when mAb S22025B was added.

[0254] KIR2DS1 (see e.g., Figs. 145-147) - The interaction between HLA-C*04:01 monomers with bound proprietary UVX peptide and KIR2DS1 transfected Ba / F3 was abrogated with the addition of mAb S22019B, S22019F, S22013A, and S22021 B.

[0255] KIR2DL5 (see e.g., Figs. 143-144) - While the interaction between recombinant CD155-Biotin and KIR2DL5A transfected Ba / F3 was initially minimal, the interaction of KIR2DL5 and its ligand was increased when mAb S22010G was added. This KIR-ligand enhancement was found to be specific for the interaction of KIR2DL5 and CD155 and not with ligand containing a similar amino acid sequence such as CD1 12 or CD1 13.

[0256] KIR2DS4 (see e.g., Figs. 140-142) - The Interaction between HLA-C*05:01 APC-conjugated tetramer with bound P2-AW peptide (IIDKSGAWV) and KIR2DS4 was completely disrupted by mAb S22012B,C,E,F,G. The mAb S22012A and S22012H also slightly disrupted this KIR-ligand interaction as well.

[0257] KIR3DL1 (see e.g., Figs. 137-139) - The interaction between HLA-B*57:01 APC-conjugated tetramer with bound ‘self-peptide’ (LSSPVTKSF) was completely disrupted by mAb S22024A,B,C,D,E,F,G,H, and S22026A,B and S2301 1 E,F,G.

[0258] KIR2DL1 (see e.g., Figs. 131-132) - The interaction between HLA-C*04:01 APC-conjugated tetramer with bound CMV-modified peptide (QYDDAVYKL) was completely disrupted by mAb S22039A,B,C,D and S22013A.

[0259] KIR2DL2 (see e.g., Figs. 133-134) - The interaction been HLA-C*07:02 monomer with bound proprietary UVX peptide and KIR2DL2 transfected Ba / F3 was completely disrupted by mAb S22036B, S22036D, and S22037E,F,G. The mAbs S22020A and S22034A,B,C,D also partially decreased KIR-ligand interaction.

[0260] KIR2DS2 (see e.g., Figs. 133, 135) - The interaction been HLA-C*07:02 monomer with bound proprietary UVX peptide and KIR2DS2 transfected Ba / F3 was completely disrupted by mAb S22032A, S22032C, S22034A,B,C,D, S22036B, S22036D, and S22038E.

[0261] KIR2DL3 (see e.g., Figs. 133, 136) - The interaction been HLA-C*07:02 monomer with bound proprietary UVX peptide and KIR2DL3 transfected Ba / F3 was completely disrupted by mAb S22036B, S22036D, S22037E, S22037F, and S22037G. The mAbs S22034A,B,C,D also partially decreased KIR-ligand interaction. Degranulation of KIR3DL1+ NK cells decreased from KIR3DL 1 specific antibody presence

[0262] To determine the effects KIR3DL1 specific antibodies have on the primary derived NK cells, IL-2 and IL-15 activated primary NK cells with K562 cell line were cultured in the presence of anti- KIR3DL1 antibodies and isotype control, and the change in CD107a expression was measured through flow cytometry. Most NK cells without KIR3DL1 + expression did not show significant change between isotype control and anti-KIR3DL1 antibodies samples, with the exception of mAb S22026A and S23011 B showing a slight increase. When comparing KIR3DL1 + NK cells, CD107a expression decreased (28.9 - 51 .8%) in comparison to KIR3DL1 - NK cells for samples with developed anti-KIR3DL1 antibodies, with the highest decrease coming from mAb S22024A, S22024B, S22024E, and S22024H (Fig. 124). The lowest antibody mediated CD107a decrease in normalized KIR3DL1 + NK cells was induced by mAb S23011A, S2301 1 B, and S23011 C.

[0263] Degranulation of KIR2DS1+ NK cells increased from KIR2DS1 specific antibody presence

[0264] Similarly, to determine the effects of KIR2DS1 specific antibodies on primary derived NK cells, anti- KIR2DS1 antibodies were added to IL-2 and IL-15 activated primary NK cells with K562 cell line and changes in CD107a expression were measured through flow cytometry. In KIR2DS1- NK cells, the addition of mAb S22019B caused a slight but significant decrease in CD107a expression compared to isotype, while mAb S22019F did not show any significant difference compared to isotype. In KIR2DS1 + NK cells, the addition of mAb S22019B and S22019F showed significant increases in CD107a expression (38, 36%, respectively) via the normalized CD107a activation ratio (Fig. 126).

[0265] Modulation of isolated NK cell response to K562 cell line by KIR2DS4 specific antibody presence

[0266] The effects of KIR2DS4 specific antibody presence on activated NK cell response were also tested using K562 co-culture. When measuring CD107a expression in all NK cells within a sample, all samples with developed anti-KIR2DS4 antibodies (S22012A,B,C,E,F,G,H) added showed 20.2% - 20.5% significant increases in CD107a expression compared to a normalized isotype (Fig. 128). Conversely, the population of CD107a negative NK cells decreased as well. In addition, when analyzing in-solution cytokine secretion by the NK cells in response to K562 cell line and anti- KIR2DS4 antibodies, the addition of KIR2DS4 showed increased secreted TNFa concentration in solution for most developed anti-KIR2DS4 antibodies, while IFNy showed a trending increase in insolution concentration as well compared to isotype (Fig. 129). When measuring for changes to K562 survival, the addition of the developed anti-KIR2DS4 antibodies shows increased live K562 cells (26.5% - 32.5%) compared to isotype control (Fig. 130). Summary of functional results for certain clones (see also Figs. 8 and 102)

[0267] S22012A (KIR2DS4):

[0268] • High flow performance and specificity - see Figs. 29-35

[0269] • Higher performance than direct mAb competitor in flow - see Figs. 105, 1 13

[0270] • Different epitope from competitor - see Fig. 114

[0271] • Partially functional ligand block effects but not as much as other clones in this target group - see Figs 140-142

[0272] • Well-defined functional effects on NK cells, including CD107a expression, cytokine expression, and K562 changes - see Figs. 127-130

[0273] S22024B (KIR3DL1 ):

[0274] • High flow performance and specificity - see Figs. 36-41

[0275] • Unique epitope from competitors - see Fig. 121

[0276] • Clear functional effect on ligand binding interaction - see Figs. 137-139

[0277] • Well-defined functional data of CD107a expression changes on NK cells - see Figs. 122- 124

[0278] S22025B (KIR3DL2):

[0279] • High flow performance and specificity - see Figs. 19-28

[0280] • Different epitope from similar clones - see Fig. 24

[0281] • Clear functional effect on ligand binding interaction - see Figs. 148-150 S22019F (KIR2DS1 ):

[0282] • High flow performance and specificity - see Figs. 9-18

[0283] • Clear functional effect on ligand binding interaction - see Figs. 145-147

[0284] • Well-defined functional data of CD107a expression changes on NK cells - see Figs. 125- 126

[0285] S22013A (KIR2DS1 / KIR2DL1):

[0286] • High flow performance and specificity - see Figs. 10, 11 , 14, 17-18, 80, 83-15

[0287] • Higher performance than direct mAb competitor in flow see Figs. 104, 112

[0288] • Clear functional effect on ligand binding interaction on both KIR targets - see Figs. 131-132 and 145-147

[0289] S22032A (KIR2DL2 / KIR2DS2):

[0290] • High flow performance and specificity - see Figs. 64-78, 86-87, 92-101

[0291] • No direct mAb competitor for staining pattern (2DL2 / 2DS2 specificity)

[0292] • Different epitope from similar clones - see Figs. 76-77

[0293] • Clear functional effect on ligand binding interaction on KIR2DS2 - see Figs. 133, 135 S22037G (KIR2DL2 / KIR2DL3):

[0294] • High flow performance and specificity - see Figs. 64-78, 88-89, 92-101

[0295] • No direct mAb competitor for staining pattern (2LD2 / 2DL3 specificity)

[0296] • Different epitope from similar clones - see Figs. 76, 78

[0297] • Clear functional effect on ligand binding interaction on both KIR targets - see Figs.133, 134, 136

[0298] S22038E (KIR2DL2 / KIR2DS2 / KIR2DL3):

[0299] • High flow performance and specificity - see Figs. 64-78, 90-91 , 92-101

[0300] • Higher performance than direct mAb competitor for staining pattern - see Figs. 133-136 S22039A (KIR2DL1 ):

[0301] • High flow performance and specificity - see Figs. 64-85

[0302] • Different epitope from direct competitor - see Fig. 84

[0303] • Clear functional effect on ligand binding interaction - see Figs. 131-132 S22010E (KIR2DL5):

[0304] • High flow performance and specificity - see Figs. 42-54

[0305] • Higher performance than direct mAb competitor - see Fig. 49

[0306] • Different epitope from direct competitor - see Fig. 50

[0307] • Can distinguish greater protein variants than direct competitor - see Figs. 46-49 S23011 E (KIR3DL3):

[0308] • High flow performance and specificity - see Figs. 55-59

[0309] • No direct Mouse mAb competitor competition

[0310] • Clear functional effect on ligand binding interaction - see Figs. 151-152

[0311] S23004D (KIR2DL4):

[0312] • High flow performance and specificity - see Figs. 1 -7

[0313] • Higher performance than direct mAb competitor - see Figs. 106, 1 14

[0314] • Different epitope from direct competitor - see Fig. 1 17

[0315] The entirety of each patent, patent application, publication and document referenced herein is incorporated by reference. Citation of patents, patent applications, publications and documents is not an admission that any of the foregoing is pertinent prior art, nor does it constitute any admission as to the contents or date of these publications or documents. Their citation is not an indication of a search for relevant disclosures. All statements regarding the date(s) or contents of the documents is based on available information and is not an admission as to their accuracy or correctness.

[0316] The technology has been described with reference to specific implementations. The terms and expressions that have been utilized herein to describe the technology are descriptive and not necessarily limiting. Certain modifications made to the disclosed implementations can be considered within the scope of the technology. Certain aspects of the disclosed implementations suitably may be practiced in the presence or absence of certain elements not specifically disclosed herein.

[0317] Each of the terms “comprising,” “consisting essentially of,” and “consisting of” may be replaced with either of the other two terms. The term “a” or “an” can refer to one of or a plurality of the elements it modifies (e.g., “a reagent” can mean one or more reagents) unless it is contextually clear either one of the elements or more than one of the elements is described. The term “about” as used herein refers to a value within 10% of the underlying parameter (i.e., plus or minus 10%; e.g., a weight of “about 100 grams” can include a weight between 90 grams and 110 grams). Use of the term “about” at the beginning of a listing of values modifies each of the values (e.g., “about 1 , 2 and 3” refers to "about 1 , about 2 and about 3"). When a listing of values is described the listing includes all intermediate values and all fractional values thereof (e.g., the listing of values "80%, 85% or 90%" includes the intermediate value 86% and the fractional value 86.4%). When a listing of values is followed by the term "or more," the term "or more" applies to each of the values listed (e.g., the listing of "80%, 90%, 95%, or more" or "80%, 90%, 95% or more" or "80%, 90%, or 95% or more" refers to "80% or more, 90% or more, or 95% or more"). When a listing of values is described, the listing includes all ranges between any two of the values listed (e.g., the listing of "80%, 90% or 95%" includes ranges of "80% to 90%, " "80% to 95%" and "90% to 95%").

[0318] Certain implementations of the technology are set forth in the claim(s) that follow(s).

Claims

What is claimed is:1 . An isolated antibody or antigen binding fragment thereof that binds one or more killer cell immunoglobulin-like receptor (KIR) protein family members or a portion or portions thereof, wherein the antibody comprises: (i) an immunoglobulin heavy chain comprising a set of heavy chain complementarity determining region (CDR) amino acid sequences, CDRH1 , CDRH2, and CDRH3; and, (ii) an immunoglobulin light chain comprising a set of light chain CDR amino acid sequences, CDRL1 , CDRL2, and CDRL3, wherein the sets of heavy chain and light chainCDRs are each chosen from the same of set A, B, C, D, E, F, G, H, I, J, K, or L:

2. The antibody or antigen binding fragment thereof of claim 1 , wherein the immunoglobulin heavy chain comprises the amino acid sequence set forth in SEQ ID NO: 2, or a sequence having at least 80% amino acid sequence identity to SEQ ID NO: 2, and wherein the immunoglobulin light chain comprises the amino acid sequence set forth in SEQ ID NO: 4, or a sequence having at least 80% amino acid sequence identity to SEQ ID NO: 4.

3. The antibody or antigen binding fragment thereof of claim 1 , wherein the immunoglobulin heavy chain comprises the amino acid sequence set forth in SEQ ID NO: 62, or a sequence having at least 80% amino acid sequence identity to SEQ ID NO: 62, and wherein the immunoglobulin light chain comprises the amino acid sequence set forth in SEQ ID NO: 64, or a sequence having at least 80% amino acid sequence identity to SEQ ID NO: 64.

4. The antibody or antigen binding fragment thereof of claim 1 , wherein the immunoglobulin heavy chain comprises the amino acid sequence set forth in SEQ ID NO: 82, or a sequence having at least 80% amino acid sequence identity to SEQ ID NO: 82, and wherein the immunoglobulin light chain comprises the amino acid sequence set forth in SEQ ID NO: 84, or a sequence having at least 80% amino acid sequence identity to SEQ ID NO: 84.

5. The antibody or antigen binding fragment thereof of claim 1 , wherein the immunoglobulin heavy chain comprises the amino acid sequence set forth in SEQ ID NO: 242, or a sequence having at least 80% amino acid sequence identity to SEQ ID NO: 242, and wherein the immunoglobulin light chain comprises the amino acid sequence set forth in SEQ ID NO: 244, or a sequence having at least 80% amino acid sequence identity to SEQ ID NO: 244.

6. The antibody or antigen binding fragment thereof of claim 1 , wherein the immunoglobulin heavy chain comprises the amino acid sequence set forth in SEQ ID NO: 402, or a sequence having at least 80% amino acid sequence identity to SEQ ID NO: 402, and wherein the immunoglobulin light chain comprises the amino acid sequence set forth in SEQ ID NO: 404, or a sequence having at least 80% amino acid sequence identity to SEQ ID NO: 404.

7. The antibody or antigen binding fragment thereof of claim 1 , wherein the immunoglobulin heavy chain comprises the amino acid sequence set forth in SEQ ID NO: 422, or a sequence having at least 80% amino acid sequence identity to SEQ ID NO: 422, and wherein the immunoglobulin light chain comprises the amino acid sequence set forth in SEQ ID NO: 424, or a sequence having at least 80% amino acid sequence identity to SEQ ID NO: 424.

8. The antibody or antigen binding fragment thereof of claim 1 , wherein the immunoglobulin heavy chain comprises the amino acid sequence set forth in SEQ ID NO: 502, or a sequence having at least 80% amino acid sequence identity to SEQ ID NO: 502, and wherein the immunoglobulin light chain comprises the amino acid sequence set forth in SEQ ID NO: 504, or a sequence having at least 80% amino acid sequence identity to SEQ ID NO: 504.

9. The antibody or antigen binding fragment thereof of claim 1 , wherein the immunoglobulin heavy chain comprises the amino acid sequence set forth in SEQ ID NO: 602, or a sequence having at least 80% amino acid sequence identity to SEQ ID NO: 602, and wherein the immunoglobulin light chain comprises the amino acid sequence set forth in SEQ ID NO: 604, or a sequence having at least 80% amino acid sequence identity to SEQ ID NO: 604.

10. The antibody or antigen binding fragment thereof of claim 1 , wherein the immunoglobulin heavy chain comprises the amino acid sequence set forth in SEQ ID NO: 742, or a sequence having at least 80% amino acid sequence identity to SEQ ID NO: 742, and wherein the immunoglobulin light chain comprises the amino acid sequence set forth in SEQ ID NO: 744, or a sequence having at least 80% amino acid sequence identity to SEQ ID NO: 744.11 . The antibody or antigen binding fragment thereof of claim 1 , wherein the immunoglobulin heavy chain comprises the amino acid sequence set forth in SEQ ID NO: 942, or a sequence having at least 80% amino acid sequence identity to SEQ ID NO: 942, and wherein the immunoglobulin light chain comprises the amino acid sequence set forth in SEQ ID NO: 944, or a sequence having at least 80% amino acid sequence identity to SEQ ID NO: 944.

12. The antibody or antigen binding fragment thereof of claim 1 , wherein the immunoglobulin heavy chain comprises the amino acid sequence set forth in SEQ ID NO: 962, or a sequence having at least 80% amino acid sequence identity to SEQ ID NO: 962, and wherein theimmunoglobulin light chain comprises the amino acid sequence set forth in SEQ ID NO: 964, or a sequence having at least 80% amino acid sequence identity to SEQ ID NO: 964.

13. The antibody or antigen binding fragment thereof of claim 1 , wherein the immunoglobulin heavy chain comprises the amino acid sequence set forth in SEQ ID NO: 982, or a sequence having at least 80% amino acid sequence identity to SEQ ID NO: 982, and wherein the immunoglobulin light chain comprises the amino acid sequence set forth in SEQ ID NO: 984, or a sequence having at least 80% amino acid sequence identity to SEQ ID NO: 984.

14. A diagnostic antibody or antigen binding fragment thereof comprising the antibody or antigen binding fragment thereof of any of claims 1 -13.

15. A kit comprising the antibody or antigen binding fragment thereof of any one of claims 1 -13.

16. A pharmaceutical composition comprising the antibody or antigen binding fragment thereof of any of claims 1 -13, and a pharmaceutically acceptable excipient.

17. An isolated nucleic acid comprising a nucleotide sequence that encodes the immunoglobulin heavy chain variable domain of the antibody or antigen binding fragment thereof of any of claims 1 -13.

18. An isolated nucleic acid comprising a nucleotide sequence that encodes the immunoglobulin light chain variable domain of the antibody or antigen binding fragment thereof of any of claims 1 -13.

19. A recombinant expression vector comprising the isolated nucleic acid of claim 17 and / or the isolated nucleic acid of claim 18.

20. A host cell comprising the nucleic acid of claim 17 and / or the nucleic acid of claim 18, or the recombinant expression vector of claim 19.21 . A recombinant expression vector comprising a first expression cassette and a second expression cassette, wherein the first expression cassette comprises a nucleic acid molecule comprising a nucleotide sequence that encodes the immunoglobulin heavy chain variable domain of any one of claims 1 -13, and the second expression cassette comprises a nucleicacid molecule comprising a nucleotide sequence that encodes an immunoglobulin light chain variable domain of the antibody or antigen binding fragment thereof of any one of claims 1 -13.

22. A host cell comprising the recombinant expression vector of claim 21 .

23. A method of detecting one or more KIR protein family members, the method comprising: contacting a sample with the antibody or antigen binding fragment thereof of any of claims 1 -13, under conditions to bind the antibody or antigen binding fragment thereof to the one or more KIR protein family members in the sample, wherein the binding generates the production of one or more KIR protein family member / antibody or antigen binding fragment thereof complexes.

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