Classifications

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  • C07K16/00—Immunoglobulins [IG], e.g. monoclonal or polyclonal antibodies
  • C07K16/18—Immunoglobulins [IG], e.g. monoclonal or polyclonal antibodies against material from animals or humans
  • C07K16/28—Immunoglobulins [IG], e.g. monoclonal or polyclonal antibodies against material from animals or humans against receptors, cell surface antigens or cell surface determinants
  • C07K16/2803—Immunoglobulins [IG], e.g. monoclonal or polyclonal antibodies against material from animals or humans against receptors, cell surface antigens or cell surface determinants against the immunoglobulin superfamily
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K39/00—Medicinal preparations containing antigens or antibodies
  • A61K39/0005—Vertebrate antigens
  • A61K39/0011—Cancer antigens
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K39/00—Medicinal preparations containing antigens or antibodies
  • A61K39/395—Antibodies; Immunoglobulins; Immune serum, e.g. antilymphocytic serum
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P35/00—Antineoplastic agents
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07K—PEPTIDES
  • C07K16/00—Immunoglobulins [IG], e.g. monoclonal or polyclonal antibodies
  • C07K16/44—Immunoglobulins [IG], e.g. monoclonal or polyclonal antibodies against material not provided for elsewhere, e.g. haptens, metals, DNA, RNA, amino acids
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K39/00—Medicinal preparations containing antigens or antibodies
  • A61K2039/505—Medicinal preparations containing antigens or antibodies comprising antibodies
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K39/00—Medicinal preparations containing antigens or antibodies
  • A61K39/0005—Vertebrate antigens
  • A61K39/0011—Cancer antigens
  • A61K39/001102—Receptors, cell surface antigens or cell surface determinants
  • A61K39/001111—Immunoglobulin superfamily
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  • C07K2317/00—Immunoglobulins specific features
  • C07K2317/20—Immunoglobulins specific features characterized by taxonomic origin
  • C07K2317/24—Immunoglobulins specific features characterized by taxonomic origin containing regions, domains or residues from different species, e.g. chimeric, humanized or veneered
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  • C07K—PEPTIDES
  • C07K2317/00—Immunoglobulins specific features
  • C07K2317/30—Immunoglobulins specific features characterized by aspects of specificity or valency
  • C07K2317/33—Crossreactivity, e.g. for species or epitope, or lack of said crossreactivity
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  • C07K2317/00—Immunoglobulins specific features
  • C07K2317/70—Immunoglobulins specific features characterized by effect upon binding to a cell or to an antigen
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  • C07—ORGANIC CHEMISTRY
  • C07K—PEPTIDES
  • C07K2317/00—Immunoglobulins specific features
  • C07K2317/70—Immunoglobulins specific features characterized by effect upon binding to a cell or to an antigen
  • C07K2317/74—Inducing cell proliferation
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  • C07K—PEPTIDES
  • C07K2317/00—Immunoglobulins specific features
  • C07K2317/70—Immunoglobulins specific features characterized by effect upon binding to a cell or to an antigen
  • C07K2317/75—Agonist effect on antigen
• • C—CHEMISTRY; METALLURGY
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  • C07K—PEPTIDES
  • C07K2317/00—Immunoglobulins specific features
  • C07K2317/70—Immunoglobulins specific features characterized by effect upon binding to a cell or to an antigen
  • C07K2317/76—Antagonist effect on antigen, e.g. neutralization or inhibition of binding
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07K—PEPTIDES
  • C07K2317/00—Immunoglobulins specific features
  • C07K2317/90—Immunoglobulins specific features characterized by (pharmaco)kinetic aspects or by stability of the immunoglobulin
  • C07K2317/92—Affinity (KD), association rate (Ka), dissociation rate (Kd) or EC50 value

Definitions

• the invention is generally related to the field of immunomodulation, and more particularly to compositions and methods for modulating Siglec-15 and signaling initiated therefrom.
• Sialic acid-binding Ig-like lectins are members of the Ig superfamily. These type 1 transmembrane proteins include a sialic acid-binding N-terminal V-set domain, variable numbers of C2-set Ig domains, a
• Siglecs Two primary subsets of Siglecs have been identified: one subset includes CD-33 and CD33- related Siglecs such as siglecs-5, -6, -7, -8, -9, 10, -11, -14 and -16 in humans, and CD33 and siglecs-E, -F, -G and -H in mice (Crocker and Redelinghuys, Biochemical Society Transactions, 36 (6): 1467- 1471 (2008)).
• the second subset is made of Sn (sialoadhesin) (siglec-1), CD22 (siglec-2), MAG (myelin- associated glycoprotein) (siglec-4) and siglec-15, all of which are well- conserved in mammals.
• Sn serumhesin
• CD22 siglec-2
• MAG myelin- associated glycoprotein
• siglec-15 siglec-15, all of which are well- conserved in mammals.
• Siglecs are differentially expressed on various subsets of leucocytes where they play a role in the positive and negative regulation of immune and inflammatory responses (McMillan and Crocker, Carbohydr. Res., 343 :2050-2056 (2008) and Crocker, et al., Nat. Rev. Immunol, 7:255 266 (2007)).
• Siglecs are expressed on immune cells and have immunosuppressive properties.
• Siglec-15 are associated with the signal adaptor molecule DNAX activation protein of 12 kDa (DAP 12), which has an immunoreceptor tyrosine-based activation motif (ITAM) and is involved in immune cell activation (Takamiya, et al., Glycobiology, 23(2): 178-87 (2013)).
• ITAM immunoreceptor tyrosine-based activation motif
• Siglec-15 is specifically expressed on macrophages and dendritic cells of spleen and lymph nodes and
• H157 cells overexpressing sTn (H157/ST6GalNAc-I) stimulated secretion of TGF- ⁇ from Siglec-15-expressing M-CSF-induced macrophages (Takamiya, et al., Glycobiology, 23(2): 178-87 (2013)).
• TGF- ⁇ from TFIP-1 cells secretion of TGF- ⁇ from TFIP-1 cells is enhanced by the overexpression of Siglec-15 in THP-1 cells and ST6GalNAc-I (the enzyme responsible for the biosynthesis of the sTn structure) in HI 57 cells, respectively, in a manner that may be at least partially dependent on Siglec-15-DAP12 induced signaling as well as one or more DAP12-independent, Sky-dependent, or possibly Sky-independent pathways.
• Siglec-15 in THP-1 cells and ST6GalNAc-I the enzyme responsible for the biosynthesis of the sTn structure
• TGF- ⁇ is produced by both tumor cells and tumor-infiltrating leukocytes including macrophages and contributes to tumor progression and metastasis, by, for example, enhancing tumor cell invasion and by inhibiting the function of immune cells (Flavell, et al., Nat Rev Immunol, 10:554-567 (2010)).
• Siglec-15 activates the DAP12-Syk pathway of signal transduction pathway that enhances TGF- ⁇ production from the myeloid cells, and eventually modifies the tumor microenvironment that is advantageous to the tumor cells (Takamiya, et al., Glycobiology, 23(2): 178-87 (2013)).
• Siglec 15 has a typical ⁇ domain (SNYENL (SEQ ID NO: 191)) in its cytoplasmic domain. Its function remains to be characterized.
• compositions for detecting and modulating Siglec-15 It is also an object of the invention to provide methods of modulating Siglec-15 and signaling initiated therefrom to increase an immune response or reduce or reverse immune suppression.
• Siglec-15 binding molecules are provided.
• the molecules are typically an antibody or antigen binding fragment thereof that immunospecifically binds to Siglec-15.
• the Siglec-15 binding molecule includes six complementarity determining regions (CDRs), wherein the CDRs includes the three light chain CDRs of a polypeptide selected from the group consisting of SEQ ID NO:3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, or 107, or a variant thereof having at least 50%, 60%, 70%, 80%, 85%, 90%, 95%, 99%, or more sequence identity to SEQ ID NO: 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, or 107, and the three heavy chain CDRs of a polypeptide selected from the group consisting of SEQ ID NO: 13, 14, 15, 16, 17, 18, 19, 20, 21,
• Siglec-15 binding molecule includes the light and/or heavy chain CDRs of one of the mouse anti-human monoclonal antibody referred to herein as 1B2, 1C3, 1H3, 1C12, 3H10, 5G12, 6F8, 8C8, 8H8, 9A5, 10G9, 6A, 28A, 63A, 71A, 77A, 80A, 82B, 83B, 92A, 93B, 99B, 104B, or 105 A.
• the Siglec-15 binding molecule includes a light chain variable region including the amino acid sequence a polypeptide selected from the group consisting of SEQ ID NO:3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, or 107, or a variant thereof having at least 50%, 60%, 70%, 80%, 85%, 90%, 95%, 99%, or more sequence identity to SEQ ID NO:3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, or 107, and/or a heavy chain variable region comprising the amino acid sequence a polypeptide selected from the group consisting of SEQ ID NO: 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, or 119, or a variant thereof having at least 50%
• the Siglec-15 binding molecule includes the light and/or heavy chain variable region(s) of one of the mouse anti- human monoclonal antibodies referred to herein as 1B2, 1C3, 1H3, 1C12, 3H10, 5G12, 6F8, 8C8, 8H8, 9A5, 10G9, 6A, 28A, 63A, 71A, 77A, 80A, 82B, 83B, 92A, 93B, 99B, 104B, or 105 A.
• Siglec-15 binding molecule binds to Siglec-15
• Siglec-15 e.g., SEQ ID NO: 1, SEQ ID NO:2, etc.
• Neu5Aca2- 6GalNAca LRRC4C
• S15-CR Siglec-15-counter-receptor
• Cells that endogenously express Siglec-15 include macrophages, dendritic cells, and cancer cells.
• the Siglec-15 binding molecule can include one or more constant domains from an immunoglobulin constant region (Fc).
• the constant domains can be human constant domains, for example, IgA, IgD, IgE, IgG or IgM domains.
• the human IgG constant domains are IgGl, IgG2, IgG3, or IgG4 domains.
• the Siglec-15 binding molecule can be detectably labeled or comprises a conjugated toxin, drug, receptor, enzyme, receptor ligand.
• the Siglec-15 binding molecule can be a monoclonal antibody, a human antibody, a chimeric antibody, a humanized antibody, or a single chain antibody, or an antigen binding fragment thereof.
• the antibody can be a monospecific, bispecific, trispecific, or multispecific antibody.
• One embodiment provides a humanized anti- SIGLEC-15 antibody having one or more variable light chains having an amino acid sequence of SEQ ID NO: 195, 197, 199, 201, or 209.
• Another embodiment provides a humanized anti- SIGLEC-15 antibody having one or more variable heavy chains having an amino acid sequence of SEQ ID NO:203, 206, or 207.
• Another embodiment provides a humanized anti- SIGLEC-15 antibody having one or more variable light chains having an amino acid sequence of SEQ ID NO: 195, 197, 199, 201, or 209 and one or more variable heavy chains having an amino acid sequence of SEQ ID NO:203, 206, and 207.
• One embodiment provides and antibody having light chain CDRs of SEQ ID NO:209, 195, 207, 199, or 201 and heavy chain CDRs of SEQ ID NO:203, 206, or 207 and combinations thereof.
• Another embodiment provides an antibody having a light chain amino acid sequence according to SEQ ID NO:209, 210 or 211.
• Another embodiment provides and antibody having a heavy chain amino sequence according to SEQ ID NO: 212, 213, 215, or 216.
• Another embodiment provides an antibody having a light chain amino acid sequence according to SEQ ID NO:209, 210 or 211 and a heavy chain amino sequence according to SEQ ID NO: 212, 213, 215, or 216.
• the Siglec-15 binding molecule is modified so that the molecule will exhibit diminished or no Fc receptor (FcR) binding activity. In some embodiments, the Siglec-15 binding molecule is modified to exhibit enhanced antibody-dependent cell-mediated cytotoxicity (ADCC) or complement dependent cytotoxicity (CDC) activities.
• ADCC antibody-dependent cell-mediated cytotoxicity
• CDC complement dependent cytotoxicity
• One embodimtne provides a fusion protein that is at least 50, 60, 70, 80, 85, 90, 95, 96, 97, 98, 99, or 100% identical to SEQ ID NO: 193 or 194.
• compositions including a Siglec-15 binding molecule and a physiologically acceptable carrier or excipient are also provided.
• the Siglec-15 binding molecule reduces or prevents binding of Siglec-15 to a ligand and/or counter-receptor thereof, reduces or prevents Siglec-15-mediated signal transduction, or a combination thereof.
• the ligand can be a sialylated glycoprotein.
• the ligand can be expressed on the surface of a tumor cell.
• Leucine-rich repeat-containing protein 4C (LRRC4C) is a ligand for Siglec-15, and may be expressed by cancer cells.
• a Siglec-15-counter-receptor may also be expressed on the surface of immune cells such as T cells, which when engaged by Siglec-15, leads to T cell inhibition.
• the methods include administering to the subject an effective amount of a Siglec-15 binding molecule, for example, in a pharmaceutical composition.
• antagonistic Siglec-15 binding molecule increases an immune response, retards or prevents tumor growth, inhibits tumor-mediated immune suppression, eliminates tumors, depletes or blocks the activity of tumor- associated macrophages (TAMs) so as to alter their activity, decreases TAM- mediated immune suppression, reduces or reverses T cell suppression, increases T cell proliferation, or a combination thereof.
• the cancer or tumor includes macrophages expressing Siglec-15.
• the Siglec-15 binding molecule can be administered to the subject in an effective amount to reduce expression and/or secretion of TGF- ⁇ by the macrophages.
• the subject has cancer or an infectious disease.
• the cancer can include cells expressing or over-expressing a ligand of Siglec-15.
• Methods of reducing osteoclast differentiation, reducing bone resorption, increasing bone formation, and combinations thereof by administering subject an effective amount of antagonistic Siglec-15 binding molecules are also provided.
• agonistic Siglec-15 binding molecule decrease an immune response, increases or enhances T cell suppression, increases T cell proliferation, or a combination thereof.
• the Siglec-15 binding molecule can be administered to the subject in an effective amount to increase expression and/or secretion of TGF- ⁇ by the macrophages.
• the subject has inflammation, an autoimmune disease, or is a transplant recipient.
• Some embodiments include administering to the subject a second therapeutic agent.
• a method of detection or diagnosis of a disease, disorder or infection can include (a) assaying the expression of Siglec-15 in cells or in a tissue sample of a subject using the disclosed Siglec-15 binding molecules and (b) comparing the level of the Siglec-15 with a control level, wherein an increase in the assayed level of Siglec-15 compared to the control level is indicative of the disease, disorder or infection.
• a method for monitoring the progression of a disease, disorder or infection can include (a) assaying the expression of Siglec-15 in cells or in a tissue sample of a subject obtained at a first time point and later time point using the disclosed Siglec-15 binding molecules; and (b) comparing the level of expression of Siglec-15 in the cells or in the tissue sample of the subject at the first and later times points, wherein an increase in the assayed level of Siglec-15 at the later time point compared to the first time point is indicative of the progression of disease, disorder or infection.
• a method for monitoring a response to a treatment includes (a) assaying the expression of Siglec-15 in cells or in a tissue sample of a subject prior to and after the treatment using the disclosed Siglec-15 binding molecules; and (b) comparing the level of Siglec-15 over time, whereby a decrease in the assayed level of Siglec-15 after treatment compared to the level of Siglec-15 prior to treatment is indicative of a favorable response to the treatment.
• Figure 1 is a curve showing the plasma antibody titer of two immunized and two non-immunized Siglec-15 knockout mice.
• Figures 2A-2C are alignments showing the sequences light chain variable region of 1B2, 1C3, 1H3, 1C12, 3H10, 5G12, 6F8, 8C8, 8H8, 9A5, 10G9, 6A, 28 A, 63 A, 77A, 80A, 82B, 83B, 92A, 93B, 99B, 104B, and 105 A and highlighting the first (2A), second (2B), and third (2C) complementarity determining regions (CDRs).
• Figures 3A-3C are alignments showing the sequences heavy chain variable region of 1B2, 1C3, 1H3, 1C12, 3H10, 5G12, 6F8, 8C8, 8H8, 9A5, 10G9, 6A, 28 A, 63 A, 77A, 80A, 82B, 83B, 92A, 93B, 99B, 104B, and 105 A and highlighting the first (3 A), second (3B), and third (3C) complementarity determining regions (CDRs).
• Figure 4A is a diagram of an assay for measuring direct binding of anti- Siglec-15 antibodies to human or mouse Siglec-15-expressing cells.
• Figure 4B (1B2, 1C3, 1C12, 1H3, 3H10, 5G12, 6F8, 8C8, 8H8, 9A5, and 10G9) and Figure 8C (6A (NC6), 28A (NC28), 63 A (NC63), 77A (NC77), 80A (NC80), 82B (NC82), 83B (NC83), 92A (NC92), 93B (NC93), 99B (NC99), 104B
• NCI 04 and 105 A (NCI 05) are bar graphs showing binding of anti-Siglec-15 antibodies (% positive cells) to Siglec-15-expressing cells in the assay illustrated in Figure 4A.
• Figure 4C is a bar graph showing binding of anti-Siglec-15 antibodies (1B2, 1C3, 1C12, 1H3, 3H10, 5G12, 6F8, 8C8, 8H8, 9A5, 10G9, 6A (NC6), 28A (NC28), 63 A (NC63), 77A (NC77), 80A (NC80), 82B (NC82), 83B (NC83), 92A (NC92), 93B (NC93), 99B (NC99), 104B (NCI 04), and 105 A (NCI 05)) (% positive cells) to formalin-fixed Siglec-15-expressing cells.
• Figures 5A-5B are line graphs showing purified 1C12, 8H8, 5G12, 3H10, 9A5, 6F8, 8C8, 1H3, 10G9, 1B2, and 1C3 Ab binding to K562.hS 15 cells (9 A, background binding subtracted) and 293T.mS 15 cells (9B) (Mean
• FIG. 5C is a dot plot binding (MFI) of purified 1B2, 1C3, 1H3, 1C12, 3H10, 5G12, 6F8, 8C8, 8H8, 9A5, and 10G9 Ab to K562.hS15 cells relative to 293T.mS15.
• Figure 6A is a bar graph showing the percentage of hS15+ U87 cells detected by each of 1B2, 1C3, 1H3, 1C12, 3H10, 5G12, 6F8, 8C8, 8H8, and 10G9 Ab.
• Figure 6B is a bar graph showing the MFI of hS15+ U87 cells detected by each of 1B2, 1C3, 1H3, 1C12, 3H10, 5G12, 6F8, 8C8, 8H8, and 10G9 Ab.
• Figure 6C is a bar graph showing the percent of S15+ U87 cells detected by each of 1B2, 1C3, 1H3, 1C12, 3H10, 5G12, 6F8, 8C8, 8H8, 9A5, and lOG9 Ab.
• Figure 7A is a cartoon illustrating an antibody blocking assay. 293T cells expressing ligand LRRC4C are treated with soluble receptor (hS15.hGl) and anti-S15 antibody, and subsequently bound receptor is detected with PE- anti-hFc antibody.
• Figure 7B is a bar graph showing the % of hS15.Gl binding for the hS 15.
• Figure 7C is a bar graph showing blocking of S 15/LRRC4C (%) for Control mAb, and 1B2, 1C3, 1H3, 8H8, 6F8, 8C8, 9A5, 1C12, 3H10, 10G9, and 5G12 antibodies.
• Figure 7D is a bar graph showing blocking of S 15/LRRC4C (%) for 1B2, 1C3, 1C12 1H3, 3H10, 5G12, 6F8, 8C8, 8H8, 9A5, and 10G9.
• Figure 7E is a bar graph showing blocking of S 15/LRRC4C (%) for 6A (NC6), 28 A (NC28), 63 A (NC63), 77A (NC77), 80A (NC80), 82B (NC82), 83B (NC83), 92A (NC92), 93B (NC93), 99B (NC99), 104B (NC 104), and 105 A (NC 105)).
• Figure 8A is a diagram of a T cell suppression assay.
• Figures 8B and 8C are bar graphs showing S15 mAb reversal of hS 15. hGl -mediated suppression of Human T Cells as the % divided of CD8+ T cells (12B) and CD4+ T cells (12C) and comparing assays carried out with (e.g., +hS15.hGl) (left hand bar in each pair) and without (e.g., -hS15.hGl) (right hand bar in each pair) hS15.hGl for antibodies 1B2, 1C3, 1C12 1H3, 3H10, 5G12, 6F8, 8C8, 8H8, 9A5, and 10G9.
• Figures 8D-8G are bar graphs showing SI 5 mAb reversal of hS15.hGl- mediated suppression of Human T Cells as the % divided of CD8+ T cells ( Figures 8D and 8F) and CD4+ T cells ( Figures 8E and 8G) for assays carried out with hS15.hGl, for antibodies 1B2, 1C3, 1C12 1H3, 3H10, 5G12, 6F8, 8C8, 8H8, 9A5, and 10G9 ( Figures 8D and 12E) and 6A (NC6), 28A (NC28), 63A (NC63), 77A (NC77), 80A (NC80), 82B (NC82), 83B (NC83), 92A (NC92), 93B (NC93), 99B (NC99), 104B (NCI 04), and 105 A (NCI 05) ( Figures 8F and 8G).
• Figures 8H and 81 are dot plots showing CD8 T cell proliferation as a function
• Figure 9 A is a diagram of an assay for measuring alteration in INFy secretion.
• Figure 9B is a bar graph showing the results of assay diagramed in Figure 13A, for antibodies 1B2, 1C3, 1C12 1H3, 3H10, 5G12, 6F8, 8C8, 8H8, 9A5, and 10G9.
• Figure 10 is a bar graph showing TRAP (Tartrate-resistant acid phosphatase) (Abs 540 nm) in the presence of antibodies 1C12, 8H8, 5G12, 3H10, 9A5, 6F8, 8C8, 1H3, 10G9, 1B2, and 1C3 in an osteoclast formation assay of fresh PBMC's isolated and enriched for monocytes 2 ways: MACS column sorting (left panel) or attachment to plastic in serum free media (right panel).
• TRAP Sterate-resistant acid phosphatase
• FIG 11 is a diagram illustrating a model for Siglec-15 negative regulation of immunity in the tumor microenvironment (TME) including Siglec- 15 (S15):Siglec-15-Counter-receptor (S15-CR) »> T cell directed inhibition of proliferation and cytokines, and/or Siglec-15:LRRC4C »> Macrophage production of TGF- ⁇ and immune suppression in the TME.
• TME tumor microenvironment
• the diagram shows myeloid cell, T cell, and cancer cell expression of Siglec-15 and ligands thereof, and signaling therefrom, as well as interactions between the molecules anti- Siglec-15 (blocking and targeting) and LRRC4C antibodies and Siglec-15 fusion proteins (non-crosslinking/blocking).
• Figure 12A is a table showing the amino acid sequence of humanized 5G12 variable light chains L1-L5.
• Figure 12B is a table showing the amino acid sequence of humanized 5G12 variable heavy chains H1-H3.
• Figure 13 A shows the sequence alignment of humanized 5G12 variable light chains VL1-V15 against murine VL.
• Figure 13B shows the sequence alignment of humanized 5G12 variable heavy chains VH1-VH3.
• Figure 14A is a line graph of % Proliferation of T cells versuse human S15 Fc ⁇ g/mL) showing % proliferation of T cells is reduced as concentration of S15 Fc increases.
• Figure 14B is a bar graph of pg/ml of IFN- ⁇ in conditioned supernatants from cells treated with 0 or 5 ⁇ g/mL of S15 Fc.
• Figure 14C is a bar graph of pg/ml of TNF-a in conditioned supernatants from cells treated with 0 or 5 ⁇ g/mL of S15 Fc.
• Figure 14D is a bar graph of pg/ml of IL-6 in conditioned supernatants from cells treated with 0 or 5 ⁇ g/mL of SI 5 Fc.
• Figures 15A and 15B are bar graphs showing the percentage of positive cells for binding of S15 mAb purified from hybridoma to cells expressing human S15 or mouse SI 5.
• Figures 16A and 16B are bar graphs of percent of Divided CD8+ T cells treated with the indicated antibodies.
• Figures 16C and 16D are bar graphs of the percentage of Divided CD4+ T cells treated with the indicated antibodies.
• Figures 17A and 17B are line graphs showing percent survival versus days post tumor cell inoculation in animals treated with 5G12.
• Figure 17C is a line graph of percentage of weight gain versus days post ID8.0VA inoculation.
• Figure 18 is a line graph of percentage of weight gain versus days post
• Figure 19A is a schematic diagram showing human CD14+ monocytes harvested from human PBMC using Mitenyi monocyte magnetic beads followed by seeding in 96-well plates in the presence of human M-CSF and human RANKL together with indicated antibodies.
• Figure 19B is a micrograph showing osteoclasts treated as indicated with 1H3.
• Figure 19C is a bar graph of absorbance 540 nm of supernatant collected after 7 days for Tartrate-resi stance acid phosphatase analysis.
• Figure 20 is a bar graph showing cytokine (pg/mL) for INF- ⁇ , IL-2, IL-4, IL-6, IL-10, IL-17A, and TNF-a.
• Figure 21 is a bar graph of absorbance 540 nm mouse RAW 264.7 macrophage cells cultured in the presence of RA KL together with the indicated antibodies.
• Figure 22 shows a comparison of exemplary humanized amino acid sequences of 1H3 variable light chains.
• Figure 23 shows a comparison of exemplary humanized amino acid sequences of 1H3 variable heavy chains.
• Figure 24 is an illustration of a proposed mode of action for Siglec-15.
• Figure 25A is FACS histogram of count versus Siglec-15 PE showing M2 macrophages express Siglec-15.
• Figure 25B is FACS histogram of count versus Siglec-15 PE for Ml macrophage.
• Figure 25C is FACS histogram of count versus Siglec -15 PE for mouse bone marrow-derived myeloid cells treated with Macrophage Colony Stimulating Factor (M-CSF).
• Figure 25D is FACS histogram of count versus Siglec -15 PE for mouse bone marrow-derived myeloid cells treated with M-CSF and interleukin-10 (IL-10).
• Figure 25E is a bar graph of MFI-PE for mouse bone marrow-derived myeloid cells treated with M-CSF or M-CSF + IL10 and stained with isotype-PE (grey box) or anti- Siglec-15 PE.
• Figure 26A is a bar graph of absorbance 450 nm for supernatants from human CD 14+ monocytes from donor #1603 seeded in plates coated with Siglec-15 Fc (left colum of concentration point) or soluble Siglec-15 (right column of each concentration point).
• Figure 26B is a bar graph of absorbance 450 nm for supernatants from human CD14+ monocytes from donor #1704 seeded in plates coated with Siglec-15 Fc (left colum of concentration point) or soluble Siglec-15 (right column of each concentration point).
• Figure 26C is a bar graph of T F-a (pg/mL) versus Siglec-15 Fc ⁇ g/mL) for cells from donor #1603.
• Figure 26D is a bar graph of IL-6 (pg/mL) versus Siglec-15 Fc ⁇ g/mL) for cells from donor #1603.
• Figure 26E is a bar graph of IL- ⁇ (pg/mL) versus Siglec-15 Fc ⁇ g/mL) for cells from donor #1603.
• Figure 26F is a bar graph of TNF-a (pg/mL) versus Siglec-15 Fc ⁇ g/mL) for cells from donor #1704.
• Figure 26G is a bar graph of IL-6 (pg/mL) versus Siglec-15 Fc ⁇ g/mL) for cells from donor #1704.
• Figure 26H is a bar graph of IL- ⁇ (pg/mL) versus Siglec-15 Fc ⁇ g/mL) for cells from donor #1704.
• Figure 27A is a diagram of an experimental protocol for Example 19.
• Figure 27B is a bar graph of % CD8 proliferation of human myeloid cells pre- treated with S15 Fc; ⁇ 2 ⁇ , ⁇ and immature DCs cocultured with CFSE labeled negatively selected autologous pan-T cells at a cell ratio of 1 myeloid cell : 2 T cell together with anti-CD3/CD28 beads (1 pan-T cell : 2 beads). Columns from left to right are: T cell alone, T cells + beads, SI 5 Fc treated, ⁇ 2 ⁇ , ⁇ , and imDC for Figures 27C to 27G.
• Figure 27C is a bar graph of IFN- ⁇ (pg/mL) for the cells as treated above.
• Figure 27D is a bar graph of TNF- ⁇ (pg/mL) for the cells as treated above.
• Figure 27E is percent CD4
• Figure 27F is a bar graph of IL-6 (pg/mL) for the cells as treated above.
• Figure 27G is a bar graph of IL-10 (pg/mL) for the cell as treated above.
• Figure 28 A is a line graph of absorbance 450 nm versus mAb ⁇ g/mL) for cells from donor 1709. Top line is control mAb and the bottom line is S15 mAb.
• Figure 28B is the same as Figure 28A but for cells from donor 1713.
• Figure 29 is a diagram illustrating the role Siglec-15 plays in osteoclast formation.
• Figure 30A is a FACS histogram of human CD 14+ monocytes treated with S15 Fc and stained with anti-a v p 3 integrin mAb at day 0.
• Figure 30B is a FACS histogram of human CD14+ monocytes treated with S15 Fc and stained with anti-a v p 3 integrin mAb at day 6.
• a molecule is said to be able to "immunospecifically bind" a second molecule if such binding exhibits the specificity and affinity of an antibody to its cognate antigen.
• Antibodies are said to be capable of immunospecifically binding to a target region or conformation ("epitope") of an antigen if such binding involves the antigen recognition site of the immunoglobulin molecule.
• An antibody that immunospecifically binds to a particular antigen may bind to other antigens with lower affinity if the other antigen has some sequence or conformational similarity that is recognized by the antigen recognition site as determined by, e.g., immunoassays, BIACORE® assays, or other assays known in the art, but would not bind to a totally unrelated antigen. Preferably, however, antibodies (and their antigen binding fragments) will not cross-react with other antigens. Antibodies may also bind to other molecules in a way that is not immunospecific, such as to FcR receptors, by virtue of binding domains in other regions/domains of the molecule that do not involve the antigen recognition site, such as the Fc region.
• a molecule is said to "physiospecifically bind" a second molecule if such binding exhibits the specificity and affinity of a receptor to its cognate binding ligand.
• a molecule can be capable of physiospecifically binding to more than one other molecule.
• antibody is intended to denote an
• variable region is intended to distinguish such domain of the immunoglobulin from domains that are broadly shared by antibodies (such as an antibody Fc domain).
• the variable region includes a "hypervariable region” whose residues are responsible for antigen binding.
• the hypervariable region includes amino acid residues from a "Complementarity Determining Region” or "CDR” (i.e., typically at approximately residues 24-34 (LI), 50-56 (L2) and 89- 97 (L3) in the light chain variable domain and at approximately residues 27-35 (HI), 50-65 (H2) and 95-102 (H3) in the heavy chain variable domain; Kabat et al, Sequences of Proteins of Immunological Interest, 5th Ed. Public Health Service, National Institutes of Health, Bethesda, MD.
• CDR Constantarity Determining Region
• residues from a "hypervariable loop” i.e., residues 26-32 (LI), 50-52 (L2) and 91-96 (L3) in the light chain variable domain and 26-32 (HI), 53-55 (H2) and 96-101 (H3) in the heavy chain variable domain; Chothia and Lesk, 1987, J. Mol. Biol. 196:901-917).
• "Framework Region” or "FR" residues are those variable domain residues other than the hypervariable region residues as herein defined.
• antibody includes monoclonal antibodies, multi-specific antibodies, human antibodies, humanized antibodies, synthetic antibodies, chimeric antibodies, camelized antibodies (See e.g., Muyldermans et al, 2001, Trends Biochem. Sci. 26:230; Nuttall et al, 2000, Cur. Pharm. Biotech. 1 :253; Reichmann and Muyldermans, 1999, J. Immunol. Meth. 231 :25; International Publication Nos. WO 94/04678 and WO 94/25591; U.S. Patent No.
• antibodies include immunoglobulin molecules of any type ⁇ e.g., IgG, IgE, IgM, IgD, IgA and IgY), class (e.g., Igd, IgG 2 , IgG 3 , IgG 4 , IgAi and IgA 2 ) or subclass.
• antigen binding fragment of an antibody refers to one or more portions of an antibody that contain the antibody's
• CDRs Complementarity Determining Regions
• framework residues that include the antibody's "variable region” antigen recognition site, and exhibit an ability to immunospecifically bind antigen.
• fragments include Fab', F(ab') 2 , Fv, single chain (ScFv), and mutants thereof, naturally occurring variants, and fusion proteins including the antibody's "variable region” antigen recognition site and a heterologous protein (e.g., a toxin, an antigen recognition site for a different antigen, an enzyme, a receptor or receptor ligand, etc.).
• fragment refers to a peptide or polypeptide including an amino acid sequence of at least 5 contiguous amino acid residues, at least 10 contiguous amino acid residues, at least 15 contiguous amino acid residues, at least 20 contiguous amino acid residues, at least 25 contiguous amino acid residues, at least 40 contiguous amino acid residues, at least 50 contiguous amino acid residues, at least 60 contiguous amino residues, at least 70 contiguous amino acid residues, at least 80 contiguous amino acid residues, at least 90 contiguous amino acid residues, at least 100 contiguous amino acid residues, at least 125 contiguous amino acid residues, at least 150 contiguous amino acid residues, at least 175 contiguous amino acid residues, at least 200 contiguous amino acid residues, or at least 250 contiguous amino acid residues.
• modulate relates to a capacity to alter an effect, result, or activity (e.g, signal transduction).
• modulation can agonistic or antagonistic.
• Antagonistic modulation can be partial (i.e., attenuating, but not abolishing) or it can completely abolish such activity (e.g., neutralizing).
• Modulation can include internalization of a receptor following binding of an antibody or a reduction in expression of a receptor on the target cell.
• Agonistic modulation can enhance or otherwise increase or enhance an activity (e.g., signal transduction).
• such modulation can alter the nature of the interaction between a ligand and its cognate receptor so as to alter the nature of the elicited signal transduction.
• the molecules can, by binding to the ligand or receptor, alter the ability of such molecules to bind to other ligands or receptors and thereby alter their overall activity.
• such modulation will provide at least a 10% change in a measurable immune system activity, more preferably, at least a 50% change in such activity, or at least a 2-fold, 5-fold, 10-fold, or still more preferably, at least a 100-fold change in such activity.
• substantially as used in the context of binding or exhibited effect, is intended to denote that the observed effect is physiologically or therapeutically relevant.
• a molecule is able to substantially block an activity of a ligand or receptor if the extent of blockage is
• a molecule is said to have substantially the same immunospecificity and/or characteristic as another molecule, if such immunospecificities and
• characteristics are greater than 60% identical, greater than 70% identical, greater than 75%) identical, greater than 80% identical, greater than 85% identical, greater than 90% identical, greater than 95% identical, or greater than 97% identical).
• co-stimulatory signals encompass positive co- stimulatory signals (e.g., signals that result in enhancing an activity) and negative co-stimulatory signals (e.g., signals that result in inhibiting an activity).
• the term "derivative" refers to an antibody or antigen- binding fragment thereof that immunospecifically binds to the same target of a parent or reference antibody but which differs in amino acid sequence from the parent or reference antibody or antigen binding fragment thereof by including one, two, three, four, five or more amino acid substitutions, additions, deletions or modifications relative to the parent or reference antibody or antigen binding fragment thereof.
• such derivatives will have substantially the same immunospecificity and/or characteristics, or the same immunospecificity and characteristics as the parent or reference antibody or antigen binding fragment thereof.
• the amino acid substitutions or additions of such derivatives can include naturally occurring (i.e., DNA-encoded) or non-naturally occurring amino acid residues.
• derivative encompasses, for example, chimeric or humanized variants, as well as variants having altered CHI, hinge, CH2, CH3 or CH4 regions, so as to form, for example antibodies, etc., having variant Fc regions that exhibit enhanced or impaired effector or binding characteristics.
• a "chimeric antibody” is a molecule in which different portions of the antibody are derived from different immunoglobulin molecules such as antibodies having a variable region derived from a non-human antibody and a human immunoglobulin constant region.
• humanized antibody refers to an
• immunoglobulin including a human framework region and one or more CDR's from a non-human (usually a mouse or rat) immunoglobulin.
• the non-human immunoglobulin providing the CDR's is called the "donor” and the human immunoglobulin providing the framework is called the "acceptor.”
• Constant regions need not be present, but if they are, they should be substantially identical to human immunoglobulin constant regions, i.e., at least about 85-99%), preferably about 95% or more identical.
• all parts of a humanized immunoglobulin, except possibly the CDR's are substantially identical to corresponding parts of natural human immunoglobulin sequences.
• a humanized antibody is an antibody including a humanized light chain and a humanized heavy chain immunoglobulin.
• a humanized antibody would not encompass a typical chimeric antibody, because, e.g., the entire variable region of a chimeric antibody is non-human.
• endogenous concentration refers to the level at which a molecule is natively expressed (i.e., in the absence of expression vectors or recombinant promoters) by a cell (which cell can be a normal cell, a cancer cell or an infected cell).
• therapeutic use refer to the elimination, reduction or amelioration of one or more symptoms of a disease or disorder exacerbated by Siglec-15 or a ligand thereof.
• a "therapeutically effective amount” refers to that amount of a therapeutic agent sufficient to mediate a clinically relevant elimination, reduction or amelioration of such symptoms. An effect is clinically relevant if its magnitude is sufficient to impact the health or prognosis of a recipient subject.
• a therapeutically effective amount may refer to the amount of therapeutic agent sufficient to delay or minimize the onset of disease, e.g., delay or minimize the spread of cancer.
• a therapeutically effective amount may also refer to the amount of the therapeutic agent that provides a therapeutic benefit in the treatment or management of a disease.
• prophylactic agent refers to an agent that can be used in the prevention of a disorder or disease prior to the detection of any symptoms of such disorder or disease.
• a “prophylactically effective” amount is the amount of prophylactic agent sufficient to mediate such protection.
• a prophylactically effective amount may also refer to the amount of the prophylactic agent that provides a prophylactic benefit in the prevention of disease.
• cancer refers to a neoplasm or tumor resulting from abnormal uncontrolled growth of cells. As used herein, cancer explicitly includes, leukemias and lymphomas.
• cancer refers to a disease involving cells that have the potential to metastasize to distal sites and exhibit phenotypic traits that differ from those of non-cancer cells, for example, formation of colonies in a three-dimensional substrate such as soft agar or the formation of tubular networks or web-like matrices in a three-dimensional basement membrane or extracellular matrix preparation.
• Non-cancer cells do not form colonies in soft agar and form distinct sphere-like structures in three- dimensional basement membrane or extracellular matrix preparations.
• an “immune cell” refers to any cell from the hemopoietic origin including, but not limited to, T cells, B cells, monocytes, dendritic cells, and macrophages.
• valency refers to the number of binding sites available per molecule.
• immunological response is the development of a beneficial humoral (antibody mediated) and/or a cellular (mediated by antigen-specific T cells or their secretion products) response directed against a peptide in a recipient patient.
• Such a response can be an active response induced by administration of immunogen or a passive response induced by administration of antibody or primed T-cells.
• a cellular immune response is elicited by the presentation of polypeptide epitopes in association with Class I or Class II MHC molecules to activate antigen-specific CD4 + T helper cells and/or CD8 + cytotoxic T cells.
• the response may also involve activation of monocytes, macrophages, NK cells, basophils, dendritic cells, astrocytes, microglia cells, eosinophils, activation or recruitment of neutrophils or other components of innate immunity.
• the presence of a cell-mediated immunological response can be determined by proliferation assays (CD4 + T cells) or CTL (cytotoxic T lymphocyte) assays.
• proliferation assays CD4 + T cells
• CTL cytotoxic T lymphocyte
• an “immunogenic agent” or “immunogen” is capable of inducing an immunological response against itself on administration to a mammal, optionally in conjunction with an adjuvant.
• the terms "individual,” “host,” “subject,: and “patient” are used interchangeably herein, and refer to a mammal, including, but not limited to, humans, rodents, such as mice and rats, and other laboratory animals.
• polypeptide refers to a chain of amino acids of any length, regardless of modification (e.g., phosphorylation or
• polypeptide includes proteins and fragments thereof.
• the polypeptides can be "exogenous,” meaning that they are “heterologous,” i.e., foreign to the host cell being utilized, such as human polypeptide produced by a bacterial cell.
• Polypeptides are disclosed herein as amino acid residue sequences. Those sequences are written left to right in the direction from the amino to the carboxy terminus.
• amino acid residue sequences are denominated by either a three letter or a single letter code as indicated as follows: Alanine (Ala, A), Arginine (Arg, R), Asparagine (Asn, N), Aspartic Acid (Asp, D), Cysteine (Cys, C), Glutamine (Gin, Q), Glutamic Acid (Glu, E), Glycine (Gly, G), Histidine (His, H),
• variable refers to a polypeptide
• polynucleotide that differs from a reference polypeptide or polynucleotide, but retains essential properties.
• a typical variant of a polypeptide differs in amino acid sequence from another, reference polypeptide. Generally, differences are limited so that the sequences of the reference polypeptide and the variant are closely similar overall and, in many regions, identical.
• a variant and reference polypeptide may differ in amino acid sequence by one or more modifications
• a substituted or inserted amino acid residue may or may not be one encoded by the genetic code.
• a variant of a polypeptide may be naturally occurring such as an allelic variant, or it may be a variant that is not known to occur naturally.
• Modifications and changes can be made in the structure of the polypeptides of the disclosure and still obtain a molecule having similar characteristics as the polypeptide (e.g., a conservative amino acid substitution).
• certain amino acids can be substituted for other amino acids in a sequence without appreciable loss of activity. Because it is the interactive capacity and nature of a polypeptide that defines that polypeptide' s biological functional activity, certain amino acid sequence substitutions can be made in a polypeptide sequence and nevertheless obtain a polypeptide with like properties.
• the hydropathic index of amino acids can be considered.
• the importance of the hydropathic amino acid index in conferring interactive biologic function on a polypeptide is generally understood in the art. It is known that certain amino acids can be substituted for other amino acids having a similar hydropathic index or score and still result in a polypeptide with similar biological activity. Each amino acid has been assigned a hydropathic index on the basis of its hydrophobicity and charge characteristics.
• Those indices are: isoleucine (+4.5); valine (+4.2); leucine (+3.8); phenylalanine (+2.8); cysteine/cystine (+2.5); methionine (+1.9); alanine (+1.8); glycine (-0.4); threonine (-0.7); serine (-0.8); tryptophan (-0.9); tyrosine (-1.3); proline (-1.6); histidine (-3.2); glutamate (-3.5); glutamine (-3.5); aspartate (-3.5); asparagine (- 3.5); lysine (-3.9); and arginine (-4.5).
• the relative hydropathic character of the amino acid determines the secondary structure of the resultant polypeptide, which in turn defines the interaction of the polypeptide with other molecules, such as enzymes, substrates, receptors, antibodies, antigens, and cofactors. It is known in the art that an amino acid can be substituted by another amino acid having a similar hydropathic index and still obtain a functionally equivalent polypeptide. In such changes, the substitution of amino acids whose hydropathic indices are within ⁇ 2 is preferred, those within ⁇ 1 are particularly preferred, and those within ⁇ 0.5 are even more particularly preferred.
• hydrophilicity can also be made on the basis of hydrophilicity, particularly where the biological functional equivalent polypeptide or peptide thereby created is intended for use in immunological embodiments.
• the following hydrophilicity values have been assigned to amino acid residues: arginine (+3.0); lysine (+3.0); aspartate (+3.0 ⁇ 1); glutamate (+3.0 ⁇ 1); serine (+0.3); asparagine (+0.2); glutamnine (+0.2); glycine (0); proline (-0.5 ⁇ 1); threonine (-0.4); alanine (-0.5); histidine (-0.5); cysteine (- 1.0); methionine (-1.3); valine (-1.5); leucine (-1.8); isoleucine (-1.8); tyrosine (- 2.3); phenylalanine (-2.5); tryptophan (-3.4).
• an amino acid can be substituted for another having a similar hydrophilicity value and still obtain a biologically equivalent, and in particular, an immunologically equivalent polypeptide.
• substitution of amino acids whose hydrophilicity values are within ⁇ 2 is preferred, those within ⁇ 1 are
• amino acid substitutions are generally based on the relative similarity of the amino acid side-chain substituents, for example, their hydrophobicity, hydrophilicity, charge, size, and the like.
• Exemplary substitutions that take various foregoing characteristics into consideration are well known to those of skill in the art and include (original residue: exemplary substitution): (Ala: Gly, Ser), (Arg: Lys), (Asn: Gin, His), (Asp: Glu, Cys, Ser), (Gin: Asn), (Glu: Asp), (Gly: Ala), (His: Asn, Gin), (He: Leu, Val), (Leu: He, Val), (Lys: Arg), (Met: Leu, Tyr), (Ser: Thr), (Thr: Ser), (Tip: Tyr), (Tyr: Tip, Phe), and (Val: He, Leu).
• Embodiments of this disclosure thus contemplate functional or biological equivalents of a polypeptide as set forth above.
• embodiments of the polypeptides can include variants having about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, or more sequence identity to the polypeptide of interest.
• the term "percent (%) sequence identity” is defined as the percentage of nucleotides or amino acids in a candidate sequence that are identical with the nucleotides or amino acids in a reference nucleic acid sequence, after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent sequence identity.
• Alignment for purposes of determining percent 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, ALIGN-2 or Megalign (DNASTAR) software. Appropriate parameters for measuring alignment, including any algorithms needed to achieve maximal alignment over the full-length of the sequences being compared can be determined by known methods.
• % sequence identity of a given nucleotides or amino acids sequence C to, with, or against a given nucleic acid sequence D is calculated as follows:
• the term "pharmaceutically acceptable carrier” encompasses any of the standard pharmaceutical carriers, such as a phosphate buffered saline solution, water and emulsions such as an oil/water or water/oil emulsion, and various types of wetting agents.
• antigenic determinant and “epitope” are used interchangeably and refer to the structure recognized by an antibody.
• a “conformational epitope” is an epitope that includes discontinuous sections of the antigen's amino acid sequence.
• Antibodies bind a conformational epitope based on 3-D surface features, shape, or tertiary structure of the antigen.
• linear epitope is an epitope that formed by a continuous sequence of amino acids from the antigen. Linear epitopes typically include about 5 to about 10 continuous amino acid residues. Antibodies bind a linear epitope based on the primary sequence of the antigen.
• a "paratope,” also called an “antigen-binding site,” is a part of an antibody which recognizes and binds to an antigen.
• Sialic acid-binding Ig-like lectin 15 (Siglec-15", also referred to as
• CD33 antigen-like 3, and CD33L3 is a type 1 transmembrane protein expressed on macrophages and/or dendritic cells of human spleen and lymph nodes
• Siglec-15 binds to sialylated glycoproteins and preferentially recognizes the
• Siglec-15 associates with the activating adaptor proteins DNAX activation protein (DAP) 12 and DAP 10 via its lysine residue (residue K274) in the transmembrane domain, indicating that it functions as an activating signaling molecule.
• Orthologs of Siglec-15 are present not only in mammals but also in other branches of vertebrates, and believed to play a conserved, regulatory role in the immune system of vertebrates.
• Siglec-15 directly regulates T cell function by inhibiting T cell proliferation and proinflammatory cytokine production. Siglec-15 indirectly affects T cell function via myeloid cells. Siglec-15 expressed on tumor cells or
• M2 macrophages interacts with its binding partner on myeloid cells providing survival and differentiation signal resulting in a unique myeloid cell population that produces T F- ⁇ , IL-6 and IL- ⁇ .
• the secreted cytokines further promote tumor growth. This subset of myeloid cells may affect T cell function by reducing IFN- ⁇ production in T cells.
• Amino acid sequences for human Siglec-15 are known in the art and include, for example,
• Human Siglec-15 includes a signal peptide sequence from amino acids 1- 19 of SEQ ID NO: 1, an extracellular domain from amino acids 20-263 of SEQ ID NO: 1 (illustrated with bold and italic lettering), a transmembrane domain from amino acids 264-284 of SEQ ID NO: 1, and a cytoplasmic domain from amino acids 285-328 of SEQ ID NO: 1.
• the Ig-like V-type domain is predicted to be from amino acids 40-158 of SEQ ID NO: 1 (illustrated with single underlining) and the Ig-like C2-type domain is predicted to be from amino acids 168-251 of SEQ ID NO: 1 (illustrated with double underlining).
• Disulfide bonds are believed to form between residues 64 and 142; 95 and 104; and 187 and 237, and glycosylation is predicted at residue 172.
• Amino acids 276-279 has been referred to as a poly-leucine domain.
• a known variant is a F273L substitution variant.
• Amino acid sequences for mouse Siglec-15 are known in the art and include, for example,
• Mouse Siglec-15 includes a signal peptide sequence from amino acids 1-
• the Ig-like V-type domain is predicted to be from amino acids 40-145 of SEQ ID NO:2 (illustrated with single underlining) and the Ig-like C2-type domain is predicted to be from amino acids 169-250 of SEQ ID NO:2 (illustrated with double underlining).
• Siglec-15-binding molecules such as antibodies and antigen binding fragments thereof and other polypeptides that bind to Siglec-15 are provided.
• the sequences of the heavy and light chain variable regions, and CDRs thereof, from mouse anti- Siglec-15 antibodies are provided below.
• Antibodies, antigen binding fragments and other polypeptides including one or more of the sequences below, and variants thereof are provided.
• antibodies, antigen binding fragments, and polypeptides including one, two, or three CDRs of an anti-Siglec-15 antibody light chain variable region and/or one, two, or three CDRs of an anti-Siglec-15 antibody heavy chain variable region that bind to Siglec-15 are provided.
• the antibodies, antigen binding fragments, and polypeptides include the light chain variable region of an anti-Siglec-15 antibody, the heavy chain variable region of an anti-Siglec-15, or a combination thereof, and can bind to Siglec-15.
• the disclosed molecules can immunospecifically bind to Siglec-15 (e.g., SEQ ID NO: l, SEQ ID NO:2, etc.).
• Siglec-15 e.g., SEQ ID NO: l, SEQ ID NO:2, etc.
• molecules are provided that can immunospecifically bind to human Siglec-15:
• Siglec-15 e.g., SEQ ID NO: 1, SEQ ID NO:2, etc.
• V arrayed on the surface of a live cell, wherein the cell is a myeloid cell such as a macrophage or dendritic cell, or a cancer cell (e.g., brain cancer cell, renal cell carcinoma cell (RCC), Ewing sarcoma cell, breast cancer cell, or ovarian cancer cell);
• a myeloid cell such as a macrophage or dendritic cell
• a cancer cell e.g., brain cancer cell, renal cell carcinoma cell (RCC), Ewing sarcoma cell, breast cancer cell, or ovarian cancer cell
• sequences of light and heavy chain variable regions for monoclonal antibodies produced by twenty-four hybridomas referred to herein as 1B2, 1C3, 1H3, 1C12, 3H10, 5G12, 6F8, 8C8, 8H8, 9A5, 10G9, 6A (also NC6 and #6), 28A (also NC28 and #28), 63A (also referred to as NC63 and #63), 71 A (also referred to as NC71 and #71), 77A (also referred to as NC77 and #77), 80A (also referred to as NC80 and #80), 82B (also referred to as NC82 and #82), 83B (also referred to as NC83 and #83), 92A (also referred to as NC92 and #92),
• 93B also referred to as NC93 and #93
• 99B also referred to as NC99 and #99
• 104B also referred to as NC104 and #104
• 105A also referred to as NCI 05 and #105
• CDRs are underlined and bolded in the context of the light and heavy chain sequences. Sequences and CDRs are also illustrated in the alignments of Figures 2A-3C.
• a nucleic acid sequence encoding the 1B2 light chain variable region is:
• 1B2 Heavy Chain CDR3 DHYHGNGSDY (SEQ ID NO:67).
• a nucleic acid sequence encoding the 1B2 heavy chain variable region is: GAGGTGCAGCTGGTGGAGTCTGGGGGAGGCTTCGTGAAGCCTGGAGGGTCCCT GAAACTCTCCTGTGCAGCCTCTGGATTCACTTTCAGTGACTATGGAATGCACT GGGTTCGTCAGGCTCCAGAGAAGGGGCTGGAGTGGGTTGCATACATTAGTAGT G G C AG TAG TAT CAT C T AC T AT G C AGAC AC AG T GAAG G G C C GAT T C AC CAT C T C CAGAGACAATGCCAAGAACACCCTGTTCCTGCAAATGACCAGTCTGAGGTCTG AGGACACGGCCATGTATTACTGTGCAAGGGACCACTACCATGGTAACGGGTCC GACTACTGGGGCCAAGGCACCACTCTCACAGTCCTCA
• DI ⁇ /MTQAAPSVPVTPGESVS ISCRSSKSLLHSNGNTYLYWFLQRPGQSPQLLI YRMSNIASGVPDRFGGSGSGTAFTLRISRVEAEDVGFYYCMQHLEYPYTFGGG TRLEIK
• a nucleic acid sequence encoding the 1C3 light chain variable region is:
• 1C3 Heavy Chain Variable Region Amino Acid Sequence is: QVQLKQSGAELVKPGASVKISCKASGYIFTDYYV WVKQRPGQGLEWIGKIGP GSVS I YYNEKFKGKAT L TADKS S S TAYMQL S S L T S E DS AVY FCAS YYYGFAYW GQGTLVTVSA
• a nucleic acid sequence encoding the 1C3 heavy chain variable region is:
• a nucleic acid sequence encoding the 1H3 light chain variable region is: GACATCCAGATGACACAGGCTTCATCCTCCTTGTCTGTATCTCTAGGAGGCAG AG T CAC CAT T AC T T G C AAG G C AAG T GAC CAC AT T AAT AAT TGGTTGGCCTGGT ATCAGCAGAAACCAGGAAATGCTCCTAGGCTCT TAATATCTGGTGCAACCAGT T TGGAAACTGGGGT TCCT TCAAGAT TCAGTGGCAGTGGATCTGGAAAGGAT TA CAC T C T CAGCAT T AC CAG T C T T T CAGAC T GAAGAT G T T GC T AC TAT TAT T AC T G T C AACAGTAT TGGAGT TCTCCTCTCACGT TCGGTGCTGGGACCAAGCTGGAGCTG AAA
• One embodiment provides a humanized anti-SIGLEC-15 antibody having a variable light chain amino acid sequence of
• Another embodiment provides a humanized anti-SIGLEC-15 antibody having a variable light chain amino acid sequence of
• Still another embodiment provides a humanized anti-SIGLEC-15 antibody having a variable light chain amino acid sequence of
• a nucleic acid sequence encoding the 1H3 heavy chain variable region is:
• One embodiment provides a humanized anti-SIGLEC 15 antibody having a variable heavy chain amino acid sequence of
• 1H3 Heavy Chain CDR1 NYGVH (SEQ ID NO:48)
• 1H3 Heavy Chain CDR2 L IWS DGS T TYNSALKS (SEQ ID NO:48)
• Another embodiment provides a humanized anti-SIGLEC 15 antibody having a variable heavy chain amino acid sequence of
• 1H3 Heavy Chain CDR1 NYGVH (SEQ ID NO:48)
• 1H3 Heavy Chain CDR2 L IWS DGS T TYASALKS (SEQ ID NO:214)
• Still another emobodiment provides a humanized anti-SIGLEC 15 antibody having a variable heavy chain amino acid sequence of
• 1H3 Heavy Chain CDR1 NYGVH (SEQ ID NO:48)
• 1H3 Heavy Chain CDR2 L IWS DGS T TYNPS LKS (SEQ ID NO:224)
• Another embodiment provides a humanized anti-SIGLEC 15 antibody having a variable heavy chain amino acid sequence of QVQLQESGPGLVKPSETLSLTCTVSGFSLSNYGVHWVRQPPGKGLEWIG LIWSEGSTTYASALKSRVTISKDTSKNQVSLKLSSVTAADTAVYYCAR HPYDDYSGYYYTMDYWGQGTLVTVS (SEQ ID NO:216) with
• a nucleic acid sequence encoding the 1C12 light chain variable region is:
• 1C12 Heavy Chain Variable Region Amino Acid Sequence is: EVQLVESGGGLVKPGGSLKLSCAASGFSFSDYGMHWVRQAPEKGLEWVAYISS GSSILYYADIVKGRFTISRDNAKNTLFLQMTSLRSEDTAMYYCARDHYHGNGS DYWGQGTTLTVSS
• 1C12 Heavy Chain CDR3 DHYHGNGSDY (SEQ ID NO:67).
• a nucleic acid sequence encoding the 1C12 heavy chain variable region is:
• 3H10 Light Chain CDR3 HQRSAYPWT (SEQ ID NO:42).
• a nucleic acid sequence encoding the 3H10 light chain variable region is:
• 3H10 Heavy Chain CDR1 GFNIKDYYMH (SEQ ID NO:50)
• 3H10 Heavy Chain CDR2 RIDPEDGDIEYDPKFQG (SEQ ID NO:50)
• 3H10 Heavy Chain CDR3 DYDYDGGWFAY (SEQ ID NO:70).
• a nucleic acid sequence encoding the 3H10 heavy chain variable region is:
• 5G12 Light Chain CDR1 KASQDINSYLS (SEQ IDNO:28)
• 5G12 Light Chain CDR2 RANRLVD (SEQ ID NO:36)
• 5G12 Light Chain CDR3 LQYDEFPYT (SEQ ID NO:43).
• a nucleic acid sequence encoding the 5G12 light chain variable region is:
• 5G12 Heavy Chain CDR1 GYTFTSYWIT (SEQ ID NO:51)
• 5G12 Heavy Chain CDR2 DIYCGSDTMHYNEKFKN (SEQ ID NO:51)
• 5G12 Heavy Chain CDR3 WWDYGSSYDYFDY (SEQ ID NO:71).
• a nucleic acid sequence encoding the 5G12 heavy chain variable region is:
• a nucleic acid sequence encoding the 6F8 light chain variable region is:
• 6F8 Heavy Chain CDR1 GYTFTDYYVN (SEQ ID NO:52)
• 6F8 Heavy Chain CDR2 KIGPGSVS I YYNEKFKD (SEQ ID NO:52)
• 6F8 Heavy Chain CDR3 YYYGFAY (SEQ ID NO:68).
• a nucleic acid sequence encoding the 6F8 heavy chain variable region is:
• a nucleic acid sequence encoding the 8C8 light chain variable region is:
• a nucleic acid sequence encoding the 8C8 heavy chain variable region is:
• a nucleic acid sequence encoding the 8H8 light chain variable region is:
• 8H8 Heavy Chain CDR1 GFTFSGFWMS (SEQ ID NO:53)
• 8H8 Heavy Chain CDR2 DINSDGSAINYAPS IKD (SEQ ID NO: 64)
• 8H8 Heavy Chain CDR3 YDDYGYFDV (SEQ ID NO:72).
• a nucleic acid sequence encoding the 8H8 heavy chain variable region is:
• a nucleic acid sequence encoding the 9A5 light chain variable region is:
• 9A5 Heavy Chain CDR3 SSPHGDY (SEQ ID NO:73).
• a nucleic acid sequence encoding the 9A5 heavy chain variable region is:
• a nucleic acid sequence encoding the 10G9 light chain variable region is:
• 10G9 Heavy Chain CDR1 GFTFSDFWMS (SEQ ID NO: 55)
• 10G9 Heavy Chain CDR2 DINSDGSAVNYAPSIKD (SEQ ID NO: 55)
• 10G9 Heavy Chain CDR3 YDDYGYFDV (SEQ ID NO:72).
• a nucleic acid sequence encoding the 10G9 heavy chain variable region is:
• a nucleic acid sequence encoding the 6 A light chain variable region is: GATGTTTTGATGACCCAAACTCCACTCTCCCTGCCTGTCAGTCTTGGAGATCA AGCCTCCATCTCTTGCAGATCTAGTCAGAGTATTGTACATAGTAATGGAAACA CCTATTTAGAATGGTACCTGCAGAAGCCAGGCCAGTCTCCAAAGCTCCTGATC TACAAAGTTTCCAACCGATTTTCTGGGGTCCCAGACAGGTTCAGTGGCAGTGG ATCAGGGACAGATTTCACACTCAGGATCAGCAGAGTGGAGGCTGAGGATCTGG GAGTTTATTACTGCTTTCAAGGTTCACATGTTCCGCTCACGTTCGGTGCTGGG ACCAAGCTGGAGCTGAAA
• a Heavy Chain CDR1 DDYMH (SEQ ID NO: 162)
• a nucleic acid sequence encoding the 6A heavy chain variable region is: GAGGTTCAGCTGCAGCAGTCTGGGGCTGAACTTGTGAGGCCAGGGGCCTCAGT CAAGTTGTCCTGCACAGCTTCTGGCTTTAACATTAAAGACGACTATATGCACT GGGTGAAACAGAGGCCTGAACAGGGCCTGGAGTGGATTGGATGCATTGATCCT GAGAATGGTGATACTGAATATGCCTCGAAATTCCAGGACAAGGCCACTATAAC AACAGACACATCCTCCAACACAGCCTACCTGCAGCTCAGCAGCCTGACATCTG AGGACACTGCCGTCTATTACTGTACTACATACGTTGGATTTGCTTACTGGGGC CAAGGGACTCTGGTCACTGTCTCTACA
• a nucleic acid sequence encoding the 28A light chain variable region is: GATGTTGTGATGACCCAGACTCCACTCACTTTGTCGATTCCCATTGGACAACC AGCCTCCATCTCTTGTAAGTCAAGTCAGAGCCTCTTAGATAGTGATGGAAAGA CATATTTGAATTGGTTGTTACAGAGGCCAGGCCAGTCTCCAAAGCGCCTCATC TATCTGGTGTCTGAACTGGACTCTGGAGTCCCTGACAGGTTCACTGGCAGTGG ATCAGGGACAGATTTCACACTGAAAATCAGCAGAGTGGAGGCTGAAGATTTGG GAGTTTATTATTGTTGGCAAGGTACACATTTTCCATTCACGTTCGGCTCGGGG ACAAAGTTGGAAATAAAA
• a nucleic acid sequence encoding the 28A heavy chain variable region is:
• a nucleic acid sequence encoding the 63A light chain variable region is:
• a nucleic acid sequence encoding the 63 A heavy chain variable region is:
• a nucleic acid sequence encoding the 71A light chain variable region is:
• a nucleic acid sequence encoding the 71 A heavy chain variable region is:
• a nucleic acid sequence encoding the 77A light chain variable region is:
• a nucleic acid sequence encoding the 77A heavy chain variable region is:
• a nucleic acid sequence encoding the 80A light chain variable region is:
• a Heavy Chain CDR1 DFYIN (SEQ ID NO: 165)
• 80A Heavy Chain CDR2 RIYPGSDETYYNEKFKD (SEQ ID NO: 175)
• WFFDV Heavy Chain CDR3 : WFFDV (SEQ ID NO: 186).
• a nucleic acid sequence encoding the 80A heavy chain variable region is:
• a nucleic acid sequence encoding the 82B light chain variable region is:
• a nucleic acid sequence encoding the 82B heavy chain variable region is:
• a nucleic acid sequence encoding the 83B light chain variable region is: GAAATCCAGATGACCCAGTCTCCATCCTCTATGTCTGCATCTCTGGGAGACAG AAT AAC CAT CAC T T GC CAGGCAAC T CAAGACAT T G T TAAGAAT T TAAAC T GG T AT C AG C AGAAAC C AG G GAAAC CCCCTTCATTCCTGATCTATTATG C AAC T GAA CTGGCAGAAGGGGTCCCATCAAGGTTCAGTGGCAGTGGGTCTGGGTCAGACTA TTCTCTGACAATCAGCAACCTGGAGTCTGAAGATTTTGCAGACTATTACTGTC TACAGTTTTATGAATTTCCGTACACGTTCGGAGGGGGGACCAAGCTGGAAATA AAA
• a nucleic acid sequence encoding the 83B heavy chain variable region is:
• a nucleic acid sequence encoding the 92A light chain variable region is:
• 92A Heavy Chain CDR3 EIYDGSSGYFDVWGT (SEQ ID NO:189).
• a nucleic acid sequence encoding the 92A heavy chain variable region is:
• a nucleic acid sequence encoding the 93B light chain variable region is:
• a nucleic acid sequence encoding the 93B heavy chain variable region is:
• a nucleic acid sequence encoding the 99B light chain variable region is: GATGTTGTGATGACCCAGACTCCACTCACTTTGTCGGTTACCATTGGACAACC AGCCTCCATCTCTTGCAAGTCAAGTCAGAGCCTCTTAGATAGTGATGGAAAGA CATATTTGAATTGGTTGTTACAGAGGCCAGGCCAGTCTCCAAAGCGCCTAATC TATCTGGTGTCTAAACTGGACTCTGGAGTCCCTGACAGGTTCACTGGCAGTGG AT C AG G GAC AGAT T T C AC AC T GAAAAT C AG C AGAG T G G G C T GAG GAT T T G G GAT T T G G GAATTTATTGCTGGCAAGGTACACATTTTCCATTCACGTTCGGCTCGGGG AC AAAG T T G GAAAT AAAA
• a nucleic acid sequence encoding the 99B heavy chain variable region is:
• 104B Light Chain Variable Region Amino Acid Sequence is: ⁇ /MTQTPLTLSVT I GQPAS I SCKSSLSLLDSDGKTYLNWLLQRPGQS PKRL I YLVSKLDSGVPDRFTGSGSGTDFTLKI IRVEAEDLGI YYCWQGTHFPFTFGSG
• 104B Light Chain CDR3 WQGTHFPFT (SEQ ID NO:45).
• a nucleic acid sequence encoding the 104B light chain variable region is:
• a nucleic acid sequence encoding the 104B heavy chain variable region is: CAGGTTCAGCTGCAGCAGTCTGGGCCTGAGCTGGCGAGGCCTGGGGCCTCAGT GAAGCTGTCCTGCAAGGCTTCTGGCTACACCTTCACAAGCTATGGTATAAGCT GGGTGAAGCAAAGAACTGGACAGGGCCTTGAGTGGATTGGACAGATTCATCCT AGAAGTGGTAATACTTACTACAATGAGAACTTCAAGGGCAAGGCCACACTGAC TGCAGCCAAATCCTCCAGCACAGCGTACCTGGAGCTCCGCAGCCTGACATCTG AGGACTCTGCGGTCTATTTCTGTGCAAGAGAGGGGGGTCCCGACTACTGGGGC CAAGGCACCACTCTCACAGTCCTCA
• 105A Light Chain CDR3 FQGSHVPLT (SEQ ID NO: 157).
• a nucleic acid sequence encoding the 105 A light chain variable region is:
• 105A Heavy Chain Variable Region Amino Acid Sequence is: EVQLQQS GAELVRPGASVKLS CTAS GFNI KDDYMHWVKQRPEQGLEW I GCIDP
• a nucleic acid sequence encoding the 105 A heavy chain variable region is:
• Siglec-15 binding molecules including antibodies and antigen binding fragments thereof, that bind to one or more Siglec-15 polypeptides or fusion proteins, or fragments or variants thereof are disclosed.
• the antibodies disclosed herein are typically monoclonal antibodies, or antigen binding fragments thereof, that bind to an epitope present on a Siglec-15 polypeptide, or fragment or fusion thereof.
• the antibody binds to a conformational epitope.
• the antibody binds to a linear epitope.
• a linear epitope can be 4, 5, 6, 7, 8, 9, 10, 11, or more continuous amino acids in length.
• the epitope can include one or more non-amino acid elements, post-translation modifications, or a combination thereof.
• post-translational modifications include, but are not limited to glycosylation, phosphorylation, acetylation, citrullination and ubiquitination.
• antibodies can bind an epitope that is formed at least in-part by one or more sugar groups.
• the antibody or antigen binding fragment thereof can bind to an epitope that is present on an endogenous Siglec-15 polypeptide, or a recombinant Siglec-15 polypeptide, or a combination thereof.
• the antibody or antigen binding fragment thereof binds to the extracellular domain, or a fragment thereof, or an epitope formed therefrom of Siglec-15.
• the antibody or antigen binding fragment thereof is a function blocking antibody that reduces or prevents Siglec-15 from binding to one or more of its ligands, reduces intracellular signaling modulated by Siglec-15, or a combination thereof.
• Siglec-15 sialylated glycoproteins and preferentially recognizes the Neu5 Aca2-6GalNAca- structure.
• the experimental Examples below illustrate that Siglec-15 binds to Leucine-rich repeat-containing protein 4C (LRRC4C) (also referred to as Netrin-Gl ligand, and NGL-1), which may be depend or independent of a Neu5 Aca2-6GalNAca- structure.
• LRRC4C Leucine-rich repeat-containing protein 4C
• Nucleic acid and polypeptide sequences for LRRC4C are known in the art and include, for example,
• Siglec-15 may also bind to a counter-receptor (S15-CR) on immune cells such as T cells.
• S15-CR counter-receptor
• a function blocking (antagonistic) Siglec-15 binding molecule reduces, inhibits, or prevent interaction between Siglec-15 and ligand thereof such as a glycoprotein having the Neu5 Aca2-6GalNAca- structure, LRRC4C, or an Siglec-15-counter-receptor.
• binding of the antibody or antigen binding fragment thereof to Siglec-15 can increase immune activation, reduce immune suppression, or a combination thereof.
• the antibody or antigen binding fragment thereof binds to the Ig-like V-type domain or the Ig-like C2-type domain of Siglec-15.
• the epitope includes the sialic acid binding site of Siglec-15, (e.g., the epitope include residue 143 of SEQ ID NCv l).
• the antibody binds to part or the all of the same epitope as monoclonal antibody 1B2, 1C3, 1H3, 1C12, 3H10, 5G12, 6F8, 8C8, 8H8, 9A5, 10G9, 6A, 28A, 63A, 71A, 77A, 80A, 82B, 83B, 92A, 93B, 99B, 104B, or 105 A.
• the epitope can be a linear epitope or a conformational epitope.
• the antibody has the same epitope specificity as monoclonal antibody 1B2, 1C3, 1H3, 1C12, 3H10, 5G12, 6F8, 8C8, 8H8, 9A5, 10G9, 6A, 28A, 63A, 71A, 77A, 80A, 82B, 83B, 92A, 93B, 99B, 104B, or 105 A.
• the Siglec-15 binding molecule includes some or all of the light chain CDRs, the entire light chain variable region, some or all of the heavy chain CDRs, the entire heavy chain variable region, or a combination thereof of any of mouse anti -human Siglec-15 antibody 1B2, 1C3, 1H3, 1C12, 3H10, 5G12, 6F8, 8C8, 8H8, 9A5, 10G9, 6A, 28A, 63A, 71A, 77A, 80A, 82B, 83B, 92A, 93B, 99B, 104B, or 105A.
• the Siglec-15-binding molecules can include a CDR that is at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical to the amino acid sequence of a CDR of the above-listed clones and which exhibit immunospecific binding to Siglec- 15.
• the disclosed molecules can include one or more of the light chain CDR having the amino acid sequences of any of SEQ ID NO:24-45 and 146-161.
• the molecule can include at least one light chain CDR1, one light chain CDR2, and one light chain CDR3.
• the molecule can include a light chain CDR1 including an amino acid sequence selected from the group consisting of SEQ ID NO:24-31 and 146-152 .
• the molecule can include a light chain CDR2 including an amino acid sequence selected from the group consisting of SEQ ID NO:32-38 and 153-156.
• the molecule can include a light chain CDR3 including an amino acid sequence selected from the group consisting of SEQ ID NO:39-45 and 157-161.
• the molecule includes a light chain CDR1, a light chain CDR2, and a light chain CDR3 wherein the light chain CDR1, the light chain CDR2, and the light chain CDR3 include the amino acid sequences:
• the disclosed molecules can include one or more of the heavy chain CDR having the amino acid sequences of any of SEQ ID NO:46-73 and 162- 190.
• the molecule can include at least one heavy chain CDR1, one heavy chain CDR2, and one heavy chain CDR3.
• the molecule can include a heavy chain CDR1 including an amino acid sequence selected from the group consisting of SEQ ID NO:46-55 and 162-169.
• the molecule can include a heavy chain CDR2 including an amino acid sequence selected from the group consisting of SEQ ID NO:56-66 and 170-181.
• the molecule can include a heavy chain CDR3 including an amino acid sequence selected from the group consisting of SEQ ID NO:67-73 and 182-190.
• the molecule includes a heavy chain CDR1, a heavy chain CDR2, and a heavy chain CDR3 wherein the heavy chain CDR1, the heavy chain CDR2, and the heavy chain CDR3 include the amino acid sequences:
• the Siglec-15-binding molecules can include an amino acid sequence of a variable heavy chain and/or variable light chain that is at least 45%, at least 50%), at least 55%, at least 60%>, at least 65%>, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 99%, or 100% identical to the amino acid sequence of the variable heavy chain and/or light chain of the antibody produced by any of the above clones, and which exhibits
• the disclosed Siglec-15-binding molecules can include a light chain variable region having the amino acids sequence of SEQ ID NO:3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, or 107, or a variant thereof comprising at least 50%, 60%, 70%, 80%, 85%, 90%, 95%, 99%, or more sequence identity to SEQ ID NO:3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, or 107, and which exhibits immunospecifically binding to Siglec-15.
• the disclosed Siglec-15-binding molecules can include a heavy chain variable region having the amino acids sequence of SEQ ID NO: 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, or 119, or a variant thereof comprising at least 50%, 60%, 70%, 80%, 85%, 90%, 95%, 99%, or more sequence identity to SEQ ID NO: 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, or 119, and which exhibits immunospecifically binding to Siglec- 15.
• the Siglec- 15-binding molecule can be an immunoglobulin molecule (e.g., an antibody, diabody, fusion protein, etc.) that includes one, two or three light chain CDRs and one, two or three heavy chain CDRs (e.g., in some embodiments, three light chain CDRs and three heavy chain CDRs), wherein the light chain CDRs include:
• the light chain CDR1, the light chain CDR2, and the light chain CDR3 mouse of anti-human Siglec-15 antibody 1B2, 1C3, 1H3, 1C12, 3H10, 5G12, 6F8, 8C8, 8H8, 9A5, 10G9, 6A, 28A, 63A, 71A, 77A, 80A, 82B, 83B, 92A, 93B, 99B, 104B, or 105A, or humanized variant thereof.
• the molecule can be an immunoglobulin molecule includes one, two or three light chain CDRs and one, two or three heavy chain CDRs (e.g., in some embodiments, three light chain CDRs and three heavy chain CDRs), wherein the heavy chain CDRs include:
• the heavy chain CDR1, the heavy chain CDR2, and the heavy chain CDR3 murine anti-human Siglec-15 antibody 1B2, 1C3, 1H3, 1C12, 3H10, 5G12, 6F8, 8C8, 8H8, 9A5, 10G9, 6A, 28A, 63A, 71A, 77A, 80A, 82B, 83B, 92A, 93B, 99B, 104B, or 105A, or a humanized variant thereof.
• the molecule can be an immunoglobulin molecule that includes one, two or three light chain CDRs and one, two or three heavy chain CDRs (e.g., in some embodiments, three light chain CDRs and three heavy chain CDRs), wherein the light chain CDRs include:
• heavy chain CDRs include:
• the antibody can have one or more CDR of murine 1B2, 1C3, 1H3, 1C12, 3H10, 5G12, 6F8, 8C8, 8H8, 9A5, 10G9, 6A, 28A, 63A, 71A, 77A, 80A, 82B, 83B, 92A, 93B, 99B, 104B, or 105 A, or a chimeric antibody thereof, or a humanized variant having the CDR(s) corresponding to the CDR(s) of murine anti-human Siglec-15 antibody 1B2, 1C3, 1H3, 1C12, 3H10, 5G12, 6F8, 8C8, 8H8, 9A5, 10G9, 6A, 28A, 63A, 71A, 77A, 80A, 82B, 83B, 92A, 93B, 99B, 104B, or 105A.
• One embodiment provides a humanized monoclonal antibody having a variable light chain amino acid sequence that is at least 45%, at least 50%, at least 55%o, at least 60%>, at least 65%>, at least 70%, at least 75%, at least 80%>, at least 85%, at least 90%, at least 95%, at least 99%, or 100% identical to the amino acid sequence selected from the group consisting of SEQ ID NO: 227, 228, and 229 and/or a variable heavy chain amino acid sequence that is at least 45%o, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 99%, or 100%) identical to the amino acid sequence selected from the group consisting of SEQ ID NO: 230, 231, 233, and 235.
• the disclosed Siglec-15-binding molecules can antibodies or antigen binding fragments thereof.
• the disclosed antibodies and antigen binding fragments thereof include whole immunoglobulin (i.e., an intact antibody) of any class, fragments thereof, and synthetic proteins containing at least the antigen binding variable domain of an antibody.
• the disclosed molecule contains both an antibody light chain as well as at least the variable domain of an antibody heavy chain.
• such molecules can further include one or more of the CHI, hinge, CH2, CH3, and CH4 regions of the heavy chain (especially, the CHI and hinge regions, or the CHI, hinge and CH2 regions, or the CHI, hinge, CH2 and CH3 regions).
• the antibody can be selected from any class of immunoglobulins, including IgM, IgG, IgD, IgA and IgE, and any isotype, including IgGi, IgG 2 , IgG 3 and IgG 4 .
• the constant domain is a complement fixing constant domain where it is desired that the antibody exhibit cytotoxic activity, and the class is typically IgGi. In other embodiments, where such cytotoxic activity is not desirable, the constant domain can be of the IgG 2 or IgG 4 class.
• the antibody can include sequences from more than one class or isotype, and selecting particular constant domains to optimize desired effector functions is within the ordinary skill in the art.
• variable domains differ in sequence among antibodies and are used in the binding and specificity of each particular antibody for its particular antigen. However, the variability is not usually evenly distributed through the variable domains of antibodies. It is typically concentrated in three segments called complementarity determining regions (CDRs) or hypervariable regions both in the light chain and the heavy chain variable domains. The more highly conserved portions of the variable domains are called the framework (FR).
• CDRs complementarity determining regions
• FR framework
• the variable domains of native heavy and light chains each comprise four FR regions, largely adopting a beta-sheet configuration, connected by three CDRs, which form loops connecting, and in some cases forming part of, the beta-sheet structure.
• the CDRs in each chain are held together in close proximity by the FR regions and, with the CDRs from the other chain, contribute to the formation of the antigen binding site of antibodies.
• fragments of antibodies which have bioactivity.
• the fragments whether attached to other sequences or not, include insertions, deletions, substitutions, or other selected modifications of particular regions or specific amino acids residues, provided the activity of the fragment is not significantly altered or impaired compared to the nonmodified antibody or antibody fragment.
• a single chain antibody can be created by fusing together the variable domains of the heavy and light chains using a short peptide linker, thereby reconstituting an antigen binding site on a single molecule.
• Single-chain antibody variable fragments (scFvs) in which the C-terminus of one variable domain is tethered to the N-terminus of the other variable domain via a 15 to 25 amino acid peptide or linker have been developed without significantly disrupting antigen binding or specificity of the binding.
• Divalent single-chain variable fragments can be engineered by linking two scFvs. This can be done by producing a single peptide chain with two VH and two VL regions, yielding tandem scFvs. ScFvs can also be designed with linker peptides that are too short for the two variable regions to fold together (about five amino acids), forcing scFvs to dimerize. This type is known as diabodies. Diabodies have been shown to have dissociation constants up to 40-fold lower than corresponding scFvs, meaning that they have a much higher affinity to their target. Still shorter linkers (one or two amino acids) lead to the formation of trimers (triabodies or tribodies). Tetrabodies have also been produced. They exhibit an even higher affinity to their targets than diabodies.
• a monoclonal antibody is obtained from a substantially homogeneous population of antibodies, i.e., the individual antibodies within the population are identical except for possible naturally occurring mutations that may be present in a small subset of the antibody molecules.
• Monoclonal antibodies include "chimeric" antibodies in which a portion of the heavy and/or light chain is identical with or homologous to corresponding sequences in antibodies derived from a particular species or belonging to a particular antibody class or subclass, while the remainder of the chain(s) is identical with or homologous to corresponding sequences in antibodies derived from another species or belonging to another antibody class or subclass, as well as fragments of such antibodies, as long as they exhibit the desired antagonistic activity.
• Chimeric antibodies and antigen binding fragments thereof including one or more of the disclosed sequences and functional variants thereof are also provided.
• Chimeric antibodies including one or more CDRs from a non-human species and framework regions from a human immunoglobulin molecule can be produced using a variety of techniques known in the art including, for example, CDR-grafting (EP 239,400;
• the disclosed molecules can be human or humanized antibodies, or antigen binding fragments thereof.
• Many non-human antibodies e.g., those derived from mice, rats, or rabbits
• Transgenic animals e.g., mice
• J(H) antibody heavy chain joining region
• the antibodies are generated in other species and
• Humanized forms of non-human (e.g., murine) antibodies are chimeric immunoglobulins, immunoglobulin chains or fragments thereof (such as Fv, Fab, Fab', F(ab') 2 , or other antigen-binding subsequences of antibodies) which contain minimal sequence derived from non- human immunoglobulin.
• Humanized antibodies include human
• immunoglobulins in which residues from a complementarity determining region (CDR) of the recipient antibody are replaced by residues from a CDR of a non-human species (donor antibody) such as mouse, rat or rabbit having the desired specificity, affinity and capacity.
• CDR complementarity determining region
• donor antibody non-human species
• Fv framework residues of the human immunoglobulin are replaced by corresponding non-human residues.
• Humanized antibodies may also contain residues that are found neither in the recipient antibody nor in the imported CDR or framework sequences.
• the humanized antibody will contain substantially all of at least one, and typically two, variable domains, in which all or substantially all of the CDR regions correspond to those of a non-human immunoglobulin and all or substantially all of the FR regions are those of a human immunoglobulin consensus sequence.
• the humanized antibody optimally also will contain at least a portion of an immunoglobulin constant region (Fc), typically that of a human immunoglobulin.
• a humanized antibody has one or more amino acid residues introduced into it from a source that is non-human. These non-human amino acid residues are often referred to as "import" residues, which are typically taken from an "import” variable domain.
• Antibody humanization techniques generally involve the use of recombinant DNA technology to manipulate the DNA sequence encoding one or more polypeptide chains of an antibody molecule. Humanization can be essentially performed by substituting rodent CDRs or CDR sequences for the corresponding sequences of a human antibody. Accordingly, a humanized form of a non-human antibody (or a fragment thereof) is a chimeric antibody or fragment, wherein substantially less than an intact human variable domain has been substituted by the corresponding sequence from a non-human species. In practice, humanized antibodies are typically human antibodies in which some CDR residues and possibly some FR residues are substituted by residues from analogous sites in rodent antibodies.
• variable domains both light and heavy
• the choice of human variable domains, both light and heavy, to be used in making the humanized antibodies can be very important in order to reduce antigenicity.
• the sequence of the variable domain of a rodent antibody is screened against the entire library of known human variable domain sequences.
• the human sequence which is closest to that of the rodent is then accepted as the human framework (FR) for the humanized antibody.
• FR human framework
• Another method uses a particular framework derived from the consensus sequence of all human antibodies of a particular subgroup of light or heavy chains. The same framework may be used for several different humanized antibodies.
• humanized antibodies can be prepared by a process of analysis of the parental sequences and various conceptual humanized products using three dimensional models of the parental and humanized sequences.
• Three dimensional immunoglobulin models are commonly available and are familiar to those skilled in the art.
• Computer programs are available which illustrate and display probable three-dimensional conformational structures of selected candidate immunoglobulin sequences. Inspection of these displays permits analysis of the likely role of the residues in the functioning of the candidate immunoglobulin sequence, i.e., the analysis of residues that influence the ability of the candidate immunoglobulin to bind its antigen.
• FR residues can be selected and combined from the consensus and import sequence so that the desired antibody characteristic, such as increased affinity for the target antigen(s), is achieved.
• the CDR residues are directly and most substantially involved in influencing antigen binding.
• a human, humanized or chimeric antibody derivative can include substantially all of at least one, and typically two, variable domains in which all or substantially all of the CDR regions correspond to those of a non-human immunoglobulin (i.e., donor antibody) and all or substantially all of the framework regions are those of a human immunoglobulin consensus sequence.
• Such antibodies can also includes at least a portion of an immunoglobulin constant region (Fc), typically that of a human immunoglobulin.
• the constant domains of such antibodies can be selected with respect to the proposed function of the antibody, in particular the effector function which may be required.
• the constant domains of such antibodies are or can include human IgA, IgD, IgE, IgG or IgM domains.
• human IgG constant domains especially of the IgGl and IgG3 isotypes are used, when the humanized antibody derivative is intended for a therapeutic use and antibody effector functions such as antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) activity are needed.
• ADCC antibody-dependent cell-mediated cytotoxicity
• CDC complement-dependent cytotoxicity
• IgG2 and IgG4 isotypes are used when the antibody is intended for therapeutic purposes and antibody effector function is not required.
• Fc constant domains including one or more amino acid modifications which alter antibody effector functions such as those disclosed in U.S. Patent
• the framework and CDR regions of a humanized antibody need not correspond precisely to the parental sequences, e.g., the donor CDR or the consensus framework can be mutagenized by substitution, insertion or deletion of at least one residue so that the CDR or framework residue at that site does not correspond to either the consensus or the donor antibody.
• the donor CDR or the consensus framework can be mutagenized by substitution, insertion or deletion of at least one residue so that the CDR or framework residue at that site does not correspond to either the consensus or the donor antibody.
• such mutations not extensive.
• at least 75% of the humanized antibody residues will correspond to those of the parental framework region (FR) and CDR sequences, more often 90%, or greater than 95%.
• Humanized antibodies can be produced using variety of techniques known in the art, including, but not limited to, CDR-grafting (European Patent No. EP 239,400; International Publication No. WO 91/09967; and U.S. Patent Nos. 5,225,539, 5,530,101, and 5,585,089), veneering or resurfacing (European Patent Nos. EP 592,106 and EP 519,596; Padlan, 1991, Molecular Immunology 28(4/5):489-498; Studnicka et al, 1994, Protein Engineering 7(6):805-814; and Roguska et al, 1994, Proc. Natl. Acad. Sci. 91 :969-973), chain shuffling (U.S. Patent No. 5,565,332), and techniques disclosed in, e.g., U.S. Patent Nos.
• framework residues in the framework regions will be substituted with the corresponding residue from the CDR donor antibody to alter, for example improve, antigen binding.
• These framework substitutions are identified by methods well known in the art, e.g., by modeling of the interactions of the CDR and framework residues to identify framework residues important for antigen binding and sequence comparison to identify unusual framework residues at particular positions. (See, e.g., Queen et al, U.S. Patent No.
• Human, chimeric or humanized derivatives of the disclosed murine anti- human Siglec-15 antibodies can be used for in vivo methods in humans.
• Murine antibodies or antibodies of other species can be advantageously employed for many uses (for example, in vitro or in situ detection assays, acute in vivo use, etc.).
• Such a human or humanized antibody can include amino acid residue substitutions, deletions or additions in one or more non-human CDRs.
• the humanized antibody derivative can have substantially the same binding, stronger binding or weaker binding when compared to a non-derivative humanized antibody.
• one, two, three, four, or five amino acid residues of the CDR have been substituted, deleted or added (i.e., mutated).
• Completely human antibodies are particularly desirable for therapeutic treatment of human subjects.
• Such human antibodies can be made by a variety of methods known in the art including phage display methods using antibody libraries derived from human immunoglobulin sequences (see U.S. Patent Nos. 4,444,887 and
• Such human antibodies can be produced using transgenic mice which are incapable of expressing functional endogenous immunoglobulins, but which can express human immunoglobulin genes.
• the human heavy and light chain immunoglobulin gene complexes can be introduced randomly or by homologous recombination into mouse embryonic stem cells.
• the human variable region, constant region, and diversity region can be introduced into mouse embryonic stem cells in addition to the human heavy and light chain genes.
• the mouse heavy and light chain immunoglobulin genes can be rendered non-functional separately or simultaneously with the introduction of human immunoglobulin loci by homologous recombination.
• homozygous deletion of the 1 ⁇ 2 region prevents endogenous antibody production.
• the modified embryonic stem cells are expanded and microinjected into blastocysts to produce chimeric mice. The chimeric mice are then bred to produce homozygous offspring which express human antibodies.
• the transgenic mice are immunized using conventional methodologies with a selected antigen, e.g., all or a portion of a polypeptide.
• Monoclonal antibodies directed against the antigen can be obtained from the immunized, transgenic mice using conventional hybridoma technology (see, e.g., U.S. Patent No. 5,916,771).
• the human immunoglobulin transgenes harbored by the transgenic mice rearrange during B cell differentiation, and subsequently undergo class switching and somatic mutation.
• Lonberg and Huszar (1995, Int. Rev. Immunol.
• DNA sequences coding for human acceptor framework sequences include but are not limited to FR segments from the human germline VH segment VH1-18 and JH6 and the human germline VL segment VK-A26 and JK4.
• one or more of the CDRs are inserted within framework regions using routine recombinant DNA techniques.
• the framework regions can be naturally occurring or consensus framework regions, and human framework regions ⁇ see, e.g., Chothia et al, 1998, "Structural Determinants In The Sequences Of Immunoglobulin Variable Domain," J. Mol. Biol. 278: 457- 479 for a listing of human framework regions).
• One embodiment provides a humanized 5G12 antibody or antigen binding fragment thereof.
• the Siglec-15-binding molecules can be single-chain antibodies.
• a single chain antibody is created by fusing together the variable domains of the heavy and light chains using a short peptide linker, thereby reconstituting an antigen binding site on a single molecule.
• Single-chain antibody variable fragments scFvs
• the linker is chosen to permit the heavy chain and light chain to bind together in their proper conformational orientation.
• Fvs lack the constant regions (Fc) present in the heavy and light chains of the native antibody.
• In vitro methods are also suitable for preparing monovalent antibodies.
• Digestion of antibodies to produce fragments thereof, particularly, Fab fragments can be accomplished using routine techniques known in the art. For instance, digestion can be performed using papain. Papain digestion of antibodies typically produces two identical antigen binding fragments, called Fab fragments, each with a single antigen binding site, and a residual Fc fragment. Pepsin treatment yields a fragment, called the F(ab') 2 fragment, that has two antigen combining sites and is still capable of cross-linking antigen.
• the Fab fragments produced in the antibody digestion also contain the constant domains of the light chain and the first constant domain of the heavy chain.
• Fab' fragments differ from Fab fragments by the addition of a few residues at the carboxy terminus of the heavy chain domain including one or more cysteines from the antibody hinge region.
• the F(ab') 2 fragment is a bivalent fragment comprising two Fab' fragments linked by a disulfide bridge at the hinge region.
• Fab'-SH is the designation herein for Fab' in which the cysteine residue(s) of the constant domains bear a free thiol group.
• Antibody fragments originally were produced as pairs of Fab' fragments which have hinge cysteines between them. Other chemical couplings of antibody fragments are also known.
• the targeting function of the antibody can be used therapeutically by coupling the antibody or a fragment thereof with a therapeutic agent.
• a therapeutic agent e.g., at least a portion of an immunoglobulin constant region (Fc)
• Such coupling of the antibody or fragment (e.g., at least a portion of an immunoglobulin constant region (Fc)) with the therapeutic agent can be achieved by making an immunoconjugate or by making a fusion protein, comprising the antibody or antibody fragment and the therapeutic agent.
• Such coupling of the antibody or fragment with the therapeutic agent can be achieved by making an immunoconjugate or by making a fusion protein, or by linking the antibody or fragment to a nucleic acid such as an siRNA, comprising the antibody or antibody fragment and the therapeutic agent.
• the antibody is modified to alter its half-life. In some embodiments, it is desirable to increase the half-life of the antibody so that it is present in the circulation or at the site of treatment for longer periods of time. For example, it may be desirable to maintain titers of the antibody in the circulation or in the location to be treated for extended periods of time.
• Antibodies can be engineered with Fc variants that extend half-life, e.g., using XtendTM antibody half-life prolongation technology (Xencor, Monrovia, CA). In other embodiments, the half-life of the anti-DNA antibody is decreased to reduce potential side effects.
• the conjugates disclosed can be used for modifying a given biological response.
• the drug moiety is not to be construed as limited to classical chemical therapeutic agents.
• the drug moiety may be a protein or polypeptide possessing a desired biological activity.
• proteins may include, for example, a toxin such as abrin, ricin A, pseudomonas exotoxin, or diphtheria toxin.
• the disclosed antibodies are monospecific, binding only to Siglec-15.
• Bispecific derivatives of such antibodies, trispecific derivatives of such antibodies or derivative antibodies of greater multi- specificity, that exhibit specificity to different immune system targets in addition to their specificity for human Siglec-15 are also provided.
• such antibodies can bind to both human Siglec-15 and to an antigen that is important for targeting the antibody to a particular cell type or tissue (for example, to an antigen associated with a cancer antigen of a tumor being treated).
• such multispecific antibody binds to molecules (receptors or ligands) involved in alternative immunomodulatory pathways, such as B7-H1, PD-1, CTLA4, TIM3, TIM4, OX40, CD40, GITR, 4-1-BB, LIGHT or LAG3, in order to enhance the immunomodulatory effects and combine multiple mechanisms of action, such as ligand blocking, immune cell activation and direct tumor targeting, in one molecule.
• molecules receptors or ligands involved in alternative immunomodulatory pathways, such as B7-H1, PD-1, CTLA4, TIM3, TIM4, OX40, CD40, GITR, 4-1-BB, LIGHT or LAG3, in order to enhance the immunomodulatory effects and combine multiple mechanisms of action, such as ligand blocking, immune cell activation and direct tumor targeting, in one molecule.
• a derivative molecule for example an antibody or antibody fragment, can be modified by chemical modifications using techniques known to those of skill in the art, including, but not limited to, specific chemical cleavage, acetylation, formulation, metabolic synthesis of tunicamycin, etc.
• the term derivative encompasses non amino acid
• amino acids that can be glycosylated ⁇ e.g., have altered mannose, 2-N-acetylglucosamine, galactose, fucose, glucose, sialic acid, 5-N-acetylneuraminic acid, 5-glycolneuraminic acid, etc. content), acetylated, pegylated, phosphorylated, amidated, derivatized by known protecting/blocking groups, proteolytic cleavage, linked to a cellular ligand or other protein, etc.
• the altered carbohydrate modifications modulate one or more of the following: solubilization of the antibody, facilitation of subcellular transport and secretion of the antibody, promotion of antibody assembly, conformational integrity, and antibody-mediated effector function.
• the altered carbohydrate modifications enhance antibody mediated effector function relative to the antibody lacking the carbohydrate modification.
• Carbohydrate modifications that lead to altered antibody mediated effector function are well known in the art (for example, see Shields, R.L. et al. (2002) "Lack Of Fucose On Human IgG N -Linked
• the disclosed antibodies can be modified by recombinant means to increase greater efficacy of the antibody in mediating the desired function.
• antibodies can be modified by substitutions using recombinant means.
• the substitutions will be conservative substitutions.
• at least one amino acid in the constant region of the antibody can be replaced with a different residue.
• the modification in amino acids includes deletions, additions, substitutions of amino acids. In some cases, such changes are made to reduce undesired activities, e.g., complement-dependent cytotoxicity.
• the antibodies are labeled by joining, either covalently or non-covalently, a substance which provides for a detectable signal.
• an antibody derivative will possess a similar or identical function as the parental antibody.
• an antibody derivative will exhibit an altered activity relative to the parental antibody. For example, a derivative antibody (or fragment thereof) can bind to its epitope more tightly or be more resistant to proteolysis than the parental antibody.
• Substitutions, additions or deletions in the derivatized antibodies can be in the Fc region of the antibody and can thereby serve to modify the binding affinity of the antibody to one or more FcyR.
• Methods for modifying antibodies with modified binding to one or more FcyR are known in the art, see, e.g., PCT Publication Nos. WO 04/029207, WO 04/029092, WO 04/028564, WO
• antibodies whose Fc region have been deleted for example, an Fab or F(ab)2, etc) or modified so that the molecule exhibits diminished or no Fc receptor (FcR) binding activity, or exhibits enhanced antibody-dependent cell-mediated cytotoxicity (ADCC) or complement dependent cytotoxicity (CDC) activities.
• the antibodies have altered affinity for an activating FcyR, e.g., FcyRIIIA. Such modifications can also have an altered Fc-mediated effector function. Modifications that affect Fc-mediated effector function are well known in the art ⁇ see U.S. Patent No.
• the modification of the Fc region results in an antibody with an altered antibody-mediated effector function, an altered binding to other Fc receptors ⁇ e.g., Fc activation receptors), an altered antibody-dependent cell-mediated cytotoxicity (ADCC) activity, an altered Clq binding activity, an altered complement-dependent cytotoxicity activity (CDC), a phagocytic activity, or any combination thereof.
• Fc activation receptors e.g., Fc activation receptors
• ADCC antibody-dependent cell-mediated cytotoxicity
• Clq binding activity e.g., Clq binding activity
• CDC complement-dependent cytotoxicity activity
• phagocytic activity e.g., phagocytic activity
• Derivatized antibodies can be used to alter the half-lives ⁇ e.g., serum half-lives) of parental antibodies in a mammal, such as a human. For example, such alteration can result in a half-life of greater than 15 days, greater than 20 days, greater than 25 days, greater than 30 days, greater than 35 days, greater than 40 days, greater than 45 days, greater than 2 months, greater than 3 months, greater than 4 months, or greater than 5 months.
• the increased half-lives of the humanized antibodies or fragments thereof in a mammal, such as a human results in a higher serum titer of said antibodies or antibody fragments in the mammal, and thus, reduces the frequency of the administration of said antibodies or antibody fragments and/or reduces the concentration of said antibodies or antibody fragments to be administered.
• Antibodies or fragments thereof having increased in vivo half-lives can be generated by techniques known to those of skill in the art. For example, antibodies or fragments thereof with increased in vivo half-lives can be generated by modifying ⁇ e.g., substituting, deleting or adding) amino acid residues identified as involved in the interaction between the Fc domain and the FcRn receptor.
• humanized antibodies can be engineered to increase biological half-lives (see, e.g. U.S. Patent No. 6,277,375).
• humanized antibodies can be engineered in the Fc-hinge domain to have increased in vivo or serum half-lives.
• Antibodies or fragments thereof with increased in vivo half-lives can be generated by attaching to said antibodies or antibody fragments polymer molecules such as high molecular weight polyethyleneglycol (PEG).
• PEG polymer molecules
• PEG can be attached to said antibodies or antibody fragments with or without a multifunctional linker either through site-specific conjugation of the PEG to the N- or C- terminus of said antibodies or antibody fragments or via epsilon-amino groups present on lysine residues. Linear or branched polymer derivatization that results in minimal loss of biological activity will be used.
• the degree of conjugation will be closely monitored by SDS-PAGE and mass spectrometry to ensure proper conjugation of PEG molecules to the antibodies.
• Unreacted PEG can be separated from antibody -PEG conjugates by, e.g., size exclusion or ion- exchange chromatography.
• the antibodies can also be modified by the methods and coupling agents described by Davis et al. (See U.S. Patent No. 4, 179,337) in order to provide compositions that can be injected into the mammalian circulatory system with substantially no immunogenic response.
• the framework residues of the humanized antibodies can be modified. Residues in the framework regions can be substituted with the corresponding residue from the CDR donor antibody to alter, for example improve, antigen binding.
• These framework substitutions can be identified by methods well known in the art, e.g., by modeling of the interactions of the CDR and framework residues to identify framework residues important for antigen binding and sequence comparison to identify unusual framework residues at particular positions. (See, e.g., U.S. Patent No.
• Siglec-15-binding molecules can be recombinantly fused or chemically conjugated (including both covalently and non-covalently conjugations) to a heterologous molecule (i.e., an unrelated molecule).
• the fusion does not necessarily need to be direct, but may occur through linker sequences.
• heterologous molecules are polypeptides having at least 10, at least 20, at least 30, at least 40, at least 50, at least 60, at least 70, at least 80, at least 90 or at least 100 amino acids.
• heterologous molecules can alternatively be enzymes, hormones, cell surface receptors, drug moieties, such as: macrophage-specific targeting reagents (such as the intracellular carboxylesterase, hCEl (Needham, L. A. et al. (2011) "Drug
• Nanoparticles A Novel Targeting Delivery System To Deliver Antigen To Macrophages And Enhance Antigen Specific T Cell Responses," Molec. Pharm. 6(5): 1506-1517), N-formyl-Met-Leu-Phe (fMLF), a macrophage-specific chemo-attractant (Wan, L. et al. (2008) "Optimizing Size And Copy Number For PEG-Fmlf (N-Formyl-Methionyl-Leucyl-Phenylalanine) Nanocarrier Uptake By Macrophages " Bioconjug. Chem. 19(l):28-38), maleylated or mannosylated protein, such as maleylated albumin (Anatelli, F.
• toxins such as abrin, ricin A, pseudomonas exotoxin ⁇ i.e., PE-40), diphtheria toxin, ricin, gelonin, or pokeweed antiviral protein
• proteins such as tumor necrosis factor, interferon ⁇ e.g., a-interferon, ⁇ - interferon
• nerve growth factor platelet derived growth factor, tissue plasminogen activator, or an apoptotic agent ⁇ e.g., tumor necrosis factor-a, tumor necrosis factor- ⁇ )
• biological response modifiers such as, for example, a lymphokine ⁇ e.g., interleukin-1 (" ⁇ L-1"), interleukin-2 ("IL-2”), interleukin-6 (“IL-6”)), granulocyte macrophage colony stimulating factor (“GM-CSF”), granulocyte colony stimulating factor (“G-CSF”), or macrophage colony stimulating factor, (“M-C
• GH hydroxy-aminoethyl-N-(2-aminoethyl)-2-aminoethyl-N-(2-aminoethyl)-2-aminoethyl-N-(2-aminoethyl)-2-aminoethyl-N-(2-aminoethyl)-2-aminoethyl-N-(2-aminoethyl)
• cytotoxins ⁇ e.g., a cytostatic or cytocidal agent, such as paclitaxol, cytochalasin B, gramicidin D, ethidium bromide, emetine, mitomycin, etoposide, tenoposide, vincristine, vinblastine, colchicin, doxorubicin, daunorubicin, dihydroxy anthracin dione, mitoxantrone, mithramycin, actinomycin D, 1 -dehydrotestosterone
• BSNU lomustine
• CCNU lomustine
• cyclothosphamide busulfan, dibromomannitol, streptozotocin, mitomycin C, and cisdichlorodiamine platinum (II) (DDP) cisplatin)
• anthracyclines ⁇ e.g., daunorubicin (formerly daunomycin) and doxorubicin
• antibiotics ⁇ e.g., dactinomycin (formerly actinomycin), bleomycin, mithramycin, and anthramycin (AMC)
• anti-mitotic agents ⁇ e.g., vincristine and vinblastine).
• the molecules are conjugated to a second antibody to form an antibody heteroconjugate as described by Segal in U.S. Patent No. 4,676,980.
• Such heteroconjugate antibodies can additionally bind to haptens (such as fluorescein, etc), or to cellular markers ⁇ e.g., 4-1-BB, B7-H1, PD-1, CD4, CD8, CD14, CD25, CD27, CD40, CD68, CD163, CTLA4, GITR, LAG-3, OX40, TIM3, TIM4, TLR2, LIGHT, etc.) or to cytokines (e.g., JL-4, IL-7, IL-10, IL-12, IL-15, IL-17, TGF-beta, IFNg, Flt3, BLys) or chemokines CCL21), etc.
• haptens such as fluorescein, etc
• cellular markers e.g., 4-1-BB, B7-H1, PD-1, CD4, CD8, CD14,
• the Fc portion of the fusion protein can be varied by isotype or subclass, can be a chimeric or hybrid, and/or can be modified, for example to improve effector functions, control of half-life, tissue accessibility, augment biophysical characteristics such as stability, and improve efficiency of production (and less costly).
• Many modifications useful in construction of disclosed fusion proteins and methods for making them are known in the art, see for example Mueller, J.P. et al. (1997) "Humanized Porcine VCAM-Specific Monoclonal Antibodies With Chimeric IgG2/G4 Constant Regions Block Human Leukocyte Binding To Porcine Endothelial Cells;' Mol. Immun. 34(6):441-452, Swann, P.G.
• the Fc region is the native IgGl, IgG2, or IgG4 Fc region.
• the Fc region is a hybrid, for example a chimeric consisting of IgG2/IgG4 Fc constant regions. Modifications to the Fc region include, but are not limited to, IgG4 modified to prevent binding to Fc gamma receptors and complement, IgGl modified to improve binding to one or more Fc gamma receptors, IgGl modified to minimize effector function (amino acid changes), IgGl with altered/no glycan (typically by changing expression host), and IgGl with altered pH-dependent binding to FcRn.
• the Fc region can include the entire hinge region, or less than the entire hinge region.
• rituximab a chimeric mouse/human IgGl monoclonal antibody against CD20
• rituximab a chimeric mouse/human IgGl monoclonal antibody against CD20
• the Fc domain can the disclosed antibodies and fragments contain one or more amino acid insertions, deletions or substitutions that reduce binding to the low affinity inhibitory Fc receptor CD32B (FcyRIIB) and retain wild-type levels of binding to or enhance binding to the low affinity activating Fc receptor CD16A (FcyRIIIA).
• Another embodiment includes IgG2-4 hybrids and IgG4 mutants that have reduced binding to FcyR, which increases their half-life.
• Representative IgG2-4 hybrids and IgG4 mutants are described in Angal, S. et al. (1993) "A Single Amino Acid Substitution Abolishes The Heterogeneity Of Chimeric Mouse/Human (Igg4) Antibody " Molec. Immunol. 30(1): 105-108; Mueller, J.P. et al. (1997) "Humanized Porcine VCAM-Specifw Monoclonal Antibodies With Chimeric IgG2/G4 Constant Regions Block Human Leukocyte Binding To Porcine Endothelial Cells " Mol. Immun.
• IgGl and/or IgG2 domain is modified; for example, Angal, S. et al. (1993) describe IgGl and IgG2 variants in which serine 241 is replaced with proline.
• the Fc domain of such molecules contains amino acid insertions, deletions or substitutions that enhance binding to CD16A.
• a large number of substitutions in the Fc domain of human IgGl that increase binding to CD16A and reduce binding to CD32B are known in the art and are described in Stavenhagen, J.B. et al. (2007) "Fc Optimization Of Therapeutic Antibodies Enhances Their Ability To Kill Tumor Cells In Vitro And Controls Tumor Expansion In Vivo Via Low-Affinity Activating Fcgamma Receptors " Cancer Res. 57(18):8882-8890.
• Exemplary variants of human IgGl Fc domains with reduced binding to CD32B and/or increased binding to CD16 A contain F243L, R929P, Y300L, V305I or P296L substitutions. These amino acid substitutions can be present in a human IgGl Fc domain in any combination.
• the human IgGl Fc domain variant contains a F243L, R929P and Y300L substitution.
• the human IgGl Fc domain variant contains a F243L, R929P, Y300L, V305I and P296L substitution.
• the human IgGl Fc domain variant contains an N297Q substitution, as this mutation abolishes FcR binding.
• the marker amino acid sequence is a hexa-histidine peptide, the hemagglutinin "HA" tag, which corresponds to an epitope derived from the influenza hemagglutinin protein (Wilson, LA. et al. (1984) "The Structure Of An Antigenic Determinant In A Protein," Cell, 37:767-778) and the "flag" tag (Knappik, A. et al. (1994) "An Improved Affinity Tag Based On The FLAG Peptide For The Detection And Purification Of Recombinant Antibody Fragments," Biotechniques 17(4): 754- 761).
• the disclosed Siglec-15-binding molecules can be conjugated to a diagnostic or therapeutic agent, or another molecule for which serum half-life is desired to be increased.
• the antibodies can be used diagnostically (in vivo, in situ or in vitro) to, for example, monitor the development or progression of a disease, disorder or infection as part of a clinical testing procedure to, e.g., determine the efficacy of a given treatment regimen or to select patients more likely to respond to a particular therapy (such as those expressing high levels of Siglec-15).
• Detection can be facilitated by coupling the molecule, such as antibody or an antigen binding fragment thereof, to a detectable substance.
• detectable substances include various enzymes, prosthetic groups, fluorescent materials, luminescent materials, bioluminescent materials, radioactive materials, positron emitting metals, and nonradioactive paramagnetic metal ions.
• the detectable substance can be coupled or conjugated either directly to the antibody or indirectly, through an intermediate (such as, for example, a linker known in the art) using techniques known in the art. See, for example, U.S. Patent No. 4,741,900 for metal ions which can be conjugated to antibodies for use as diagnostics.
• Such diagnosis and detection can be accomplished by coupling the antibody to detectable substances including, but not limited to, various enzymes, enzymes including, but not limited to, horseradish peroxidase, alkaline phosphatase, beta-galactosidase, or acetylcholinesterase; prosthetic group complexes such as, but not limited to, streptavidin/biotin and
• avidin/biotin avidin/biotin
• fluorescent materials such as, but not limited to, umbelliferone, fluorescein, fluorescein isothiocyanate, rhodamine, dichlorotriazinylamine fluorescein, dansyl chloride or phycoerythrin
• luminescent material such as, but not limited to, luminol
• bioluminescent materials such as, but not limited to, luciferase, luciferin, and aequorin
• radioactive material such as, but not limited to, bismuth ( 213 Bi), carbon ( 14 C), chromium ( 51 Cr), cobalt ( 57 Co), fluorine ( 18 F), gadolinium ( 153 Gd, 159 Gd), gallium ( 68 Ga, 67 Ga), germanium ( 68 Ge), holmium ( 166 Ho), indium ( 115 In, 113 In, 112 In, U1 ln), iodine ( 131 I,
• the disclosed molecules can be attached to solid supports, which are particularly useful for immunoassays or purification of the target antigen or of other molecules that are capable of binding to target antigen that has been
• Such solid supports include, but are not limited to, glass, cellulose, polyacrylamide, nylon, polystyrene, polyvinyl chloride or polypropylene.
• Nucleic acid molecules that encode any such antibodies, fusion proteins or fragments, as well as vector molecules (such as plasmids) that are capable of transmitting or of replicating such nucleic acid molecules are also disclosed.
• the nucleic acids can be single-stranded, double-stranded, can contain both single-stranded and double-stranded portions.
• the Siglec-15-binding molecules can be produced by any method known in the art useful for the production of polypeptides, e.g., in vitro synthesis, recombinant DNA production, and the like.
• the humanized antibodies are typically produced by recombinant DNA technology.
• the antibodies can be produced using recombinant immunoglobulin expression technology.
• the recombinant production of immunoglobulin molecules, including humanized antibodies are described in U. S. Patent No. 4,816,397 (Boss et al.), U. S. Patent Nos. 6,331,415 and 4,816,567 (both to Cabilly et al.), U.K. patent GB 2, 188,638 (Winter et al), and U.K.
• An exemplary process for the production of the recombinant chimeric antibodies can include the following: a) constructing, by conventional molecular biology methods, an expression vector that encodes and expresses an antibody heavy chain in which the CDRs and variable region of an anti-Siglec-15 antibody are fused to an Fc region derived from a human immunoglobulin, thereby producing a vector for the expression of a chimeric antibody heavy chain; b) constructing, by conventional molecular biology methods, an expression vector that encodes and expresses an antibody light chain of the murine anti-human Siglec-15 monoclonal antibody, thereby producing a vector for the expression of chimeric antibody light chain; c) transferring the expression vectors to a host cell by conventional molecular biology methods to produce a transfected host cell for the expression of chimeric antibodies; and d) culturing the transfected cell by conventional cell culture techniques so as to produce chimeric antibodies.
• An exemplary process for the production of the recombinant humanized antibodies can include the following: a) constructing, by conventional molecular biology methods, an expression vector that encodes and expresses an anti- human Siglec-15 heavy chain in which the CDRs and a minimal portion of the variable region framework that are required to retain donor antibody binding specificity are derived from the humanized variants of anti-human Siglec-15 antibody(ies), and the remainder of the antibody is derived from a human immunoglobulin, thereby producing a vector for the expression of a humanized antibody heavy chain; b) constructing, by conventional molecular biology methods, an expression vector that encodes and expresses an antibody light chain in which the CDRs and a minimal portion of the variable region framework that are required to retain donor antibody binding specificity are derived from a non-human immunoglobulin, such as the disclosed murine anti- human Siglec-15 antibodies, and the remainder of the antibody is derived from a human immunoglobulin, thereby producing a vector for the expression of humanized antibody light
• host cells can be co-transfected with such expression vectors, which can contain different selectable markers but, with the exception of the heavy and light chain coding sequences, can be identical. This procedure provides for equal expression of heavy and light chain polypeptides.
• a single vector can be used which encodes both heavy and light chain polypeptides.
• the coding sequences for the heavy and light chains can include cDNA or genomic DNA or both.
• the host cell used to express the recombinant antibody can be either a bacterial cell such as
• Escherichia coli or a eukaryotic cell (e.g., a Chinese hamster ovary (CHO) cell or a HEK-293 cell).
• a eukaryotic cell e.g., a Chinese hamster ovary (CHO) cell or a HEK-293 cell.
• the choice of expression vector is dependent upon the choice of host cell, and can be selected so as to have the desired expression and regulatory characteristics in the selected host cell.
• Other cell lines that can be used include, but are not limited to, CHO-K1, NSO, and PER.C6 (Crucell, Leiden, Netherlands).
• any of the disclosed antibodies can be used to generate anti-idiotype antibodies using techniques well known to those skilled in the art (see, e.g., Greenspan, N.S. et al. (1989) "Idiotypes: Structure And Immunogenicity,” FASEB J. 7:437-444; and Nisinoff, A. (1991) "Idiotypes: Concepts And
• Siglec-15 ligands such as Siglec-15 proteins, Siglec-15 fusion proteins, and fragments and variants thereof are also provided.
• the Siglec-15 ligand-binding molecule can bind to Siglec-15 ligand such as a sialylated glycoprotein, LRRC4C, a Siglec-15-counter receptor, etc.
• the Siglec-15 ligand-binding molecule can induce signal transduction through the Siglec-15 ligand.
• the Siglec-15 ligand-binding molecule blocks or otherwise reduces interaction between Siglec- 15 and its ligand, without inducing signal transduction through Siglec-15 or its ligand.
• Siglec-15 ligand-binding molecules can be used to modulate Siglec-15 activity as discussed in more detail below and illustrated in the Examples, and can be used to therapeutically to treat a subject in need thereof.
• the Siglec-15 ligand-binding molecule is Siglec-
• the Siglec-15 ligand-binding molecules includes a polypeptide at least 50, 60, 70, 80, 85, 90, 95, 96, 97, 98, 99, or 100% identical to SEQ ID NO: l or 2, or a fragment thereof such as the extracellular domain, or a subdomain thereof such as the IgV domain, the IgC domain or the combination thereof.
• the Siglec-15 polypeptide is soluble or otherwise cell-free.
• the Siglec-15 lacks one or more of the transmembrane domain, the cytoplasmic domain, or the leader sequence.
• the Siglec-15 ligand-binding molecule is a Siglec-
• Siglec-15 fusion polypeptides can have a first fusion partner comprising all or a part of a Siglec- 15 protein fused (i) directly to a second polypeptide or, (ii) optionally, fused to a linker peptide sequence that is fused to the second polypeptide.
• the fusion proteins optionally contain a domain that functions to dimerize or multimerize two or more fusion proteins. In some embodiments the fusion protein is not or does not dimerize or multimerize.
• the peptide/polypeptide linker domain can either be a separate domain, or alternatively can be contained within one of one of the other domains (Siglec-15 polypeptide or second polypeptide) of the fusion protein.
• the domain that functions to dimerize or multimerize the fusion proteins can either be a separate domain, or alternatively can be contained within one of one of the other domains (Siglec-15 polypeptide, second polypeptide or peptide/polypeptide linker domain) of the fusion protein.
• the dimerization/multimerization domain and the peptide/polypeptide linker domain are the same. Fusion proteins disclosed herein are of formula I:
• N represents the N-terminus of the fusion protein
• C represents the C-terminus of the fusion protein
• Ri is a Siglec-15 polypeptide
• R 2 is an optional peptide/polypeptide linker domain
• R 3 is a second polypeptide.
• R 3 may be the Siglec-15 polypeptide and Ri may be the second polypeptide.
• the fusion proteins can be dimerized or multimerized. Dimerization or multimerization can occur between or among two or more fusion proteins through dimerization or multimerization domains. Alternatively, dimerization or multimerization of fusion proteins can occur by chemical crosslinking. The dimers or multimers that are formed can be homodimeric/homomultimeric or heterodimeric/heteromultimeric. As discussed above, in some embodiments the fusion protein is not or does not dimerize or multimerize.
• the second polypeptide contains one or more domains of an immunoglobulin heavy chain constant region, for example an amino acid sequence corresponding to the hinge, C H 2 and/or C H 3 regions of a human immunoglobulin Cyl chain, the hinge, C H 2 and/or C H 3 regions of a murine immunoglobulin Oy2a chain, C H 2 and/or C H 3 regions of a human immunoglobulin Oyl, ect.
• an immunoglobulin heavy chain constant region for example an amino acid sequence corresponding to the hinge, C H 2 and/or C H 3 regions of a human immunoglobulin Cyl chain, the hinge, C H 2 and/or C H 3 regions of a murine immunoglobulin Oy2a chain, C H 2 and/or C H 3 regions of a human immunoglobulin Oyl, ect.
• the Fc portion of the fusion protein may be varied by isotype or subclass, may be a chimeric or hybrid, and/or may be modified, for example to improve effector functions, control of half-life, tissue accessibility, augment biophysical characteristics such as stability, and improve efficiency of production (and less costly).
• Many modifications useful in construction of disclosed fusion proteins and methods for making them are known in the art, see for example Mueller, et al., Mol. Immun., 34(6):441-452 (1997), Swann, et al., Cur. Opin. Immun., 20:493-499 (2008), and Presta, Cur. Opin. Immun. 20:460- 470 (2008).
• the Fc region is the native IgGl, IgG2, or IgG4 Fc region.
• the Fc region is a hybrid, for example a chimeric consisting of IgG2/IgG4 Fc constant regions.
• Modifications to the Fc region include, but are not limited to, IgG4 modified to prevent binding to Fc gamma receptors and complement, IgGl modified to improve binding to one or more Fc gamma receptors, IgGl modified to minimize effector function (amino acid changes), IgGl with altered/no glycan (typically by changing expression host), and IgGl with altered pH-dependent binding to FcRn.
• the Fc region may include the entire hinge region, or less than the entire hinge region.
• rituximab a chimeric mouse/human IgGl monoclonal antibody against CD20
• rituximab a chimeric mouse/human IgGl monoclonal antibody against CD20
• the Fc domain may contain one or more amino acid insertions, deletions or substitutions that reduce binding to the low affinity inhibitory Fc receptor CD32B (FcyRIIB) and retain wild-type levels of binding to or enhance binding to the low affinity activating Fc receptor CD16A (FcyRIIIA).
• Another embodiment includes IgG2-4 hybrids and IgG4 mutants that have reduce binding to FcR which increase their half life.
• Representative IG2-4 hybrids and IgG4 mutants are described in Angal, S. et al., Molecular
• IgGl and/or IgG2 domain is deleted for example, Angal et al. describe IgGl and IgG2 having serine 241 replaced with a proline.
• the Fc domain contains amino acid insertions, deletions or substitutions that enhance binding to CD16A.
• a large number of substitutions in the Fc domain of human IgGl that increase binding to CD16A and reduce binding to CD32B are known in the art and are described in
• Exemplary variants of human IgGl Fc domains with reduced binding to CD32B and/or increased binding to CD16A contain F243L, R929P, Y300L, V305I or P296L
• the human IgGl Fc domain variant contains a F243L, R929P and Y300L substitution. In another embodiment, the human IgGl Fc domain variant contains a F243L, R929P, Y300L, V305I and P296L substitution. In another embodiment, the human IgGl Fc domain variant contains an N297Q substitution, as this mutation abolishes FcR binding.
• the disclosed fusion proteins optionally contain a peptide or polypeptide linker domain that separates the Siglec-15 polypeptide from the second polypeptide.
• the linker domain contains the hinge region of an immunoglobulin.
• the hinge region is derived from a human immunoglobulin. Suitable human immunoglobulins that the hinge can be derived from include IgG, IgD and IgA. In a preferred
• the hinge region is derived from human IgG. Amino acid sequences of immunoglobulin hinge regions and other domains are well known in the art.
• An exemplary fusion protein is Siglecl5 ECD-IgGl Fc Fusion Protein (L234F/L235E/P331 S).
• CPPCPAPEFE GGPSVFL FPPKPKDTLMI SRT PEVTCWVDVSHEDPEVKFNWY VDGVEVHNAKTKPREEQYNS TYRWSVLTVLHQDWLNGKEYKCKVSNKALPAS I EKT I SKAKGQPRE PQVYTLPPSRDELTKNQVS LTCLVKGFYPS D IAVEWE SN GQPENNYKT T PPVLDS DGS FFLYSKLTVDKSRWQQGNVFS CSVMHEALHNHYT QKS LS LS PG (SEQ ID NO: 193).
• a Murine Leader Sequence is illustrated in underlined.
• a Siglec- 15 extracellular domain (ECD) is in italics.
• a Hinge Region is double underlined. The remaining sequence is derived from IgGl Fc. L234F/L235E/P331 S mutations in the IgGl Fc domain bolded and dotted-underlined
• the leader sequence is cleaved or otherwise missing from fusion protein.
• the fusion protein can have the sequence:
• the fusion protein is at least 50, 60, 70, 80, 85, 90, 95, 96, 97, 98, 99, or 100% identical to SEQ ID NO: 193 or 194.
• the leader sequence, the linker (e.g., the hinge region), the second fusion partner (e.g., IgGl Fc domain), or a combination thereof are substitute for another sequence(s) (e.g., an alternative leader sequence, hinge, Fc domain, etc.).
• Suitable substitutes are well known in the art. See, for example, U.S. Patent No. 9,005,616, which is specifically incorporated by reference in its entirety.
• Vectors encoding Siglec-15 polypeptides, fragments and fusions thereof are also provided. Nucleic acids, such as those described above, can be inserted into vectors for expression in cells. Thus cells containing and expressing Siglec- 15 polypeptides, fragments and fusions thereof are also provided.
• a "vector” is a replicon, such as a plasmid, phage, virus or cosmid, into which another DNA segment may be inserted so as to bring about the replication of the inserted segment.
• Vectors can be expression vectors.
• An "expression vector” is a vector that includes one or more expression control sequences, and an “expression control sequence” is a DNA sequence that controls and regulates the transcription and/or translation of another DNA sequence.
• Nucleic acids in vectors can be operably linked to one or more expression control sequences.
• "operably linked” means incorporated into a genetic construct so that expression control sequences effectively control expression of a coding sequence of interest.
• expression control sequences include promoters, enhancers, and transcription terminating regions.
• a promoter is an expression control sequence composed of a region of a DNA molecule, typically within 100 nucleotides upstream of the point at which transcription starts (generally near the initiation site for RNA polymerase II). To bring a coding sequence under the control of a promoter, it is necessary to position the translation initiation site of the translational reading frame of the polypeptide between one and about fifty nucleotides downstream of the promoter.
• Enhancers provide expression specificity in terms of time, location, and level. Unlike promoters, enhancers can function when located at various distances from the transcription site. An enhancer also can be located downstream from the transcription initiation site.
• a coding sequence is
• RNA polymerase is able to transcribe the coding sequence into mRNA, which then can be translated into the protein encoded by the coding sequence.
• Suitable expression vectors include, without limitation, plasmids and viral vectors derived from, for example, bacteriophage, baculoviruses, tobacco mosaic virus, herpes viruses, cytomegalo virus, retroviruses, vaccinia viruses, adenoviruses, and adeno-associated viruses. Numerous vectors and expression systems are commercially available from such corporations as Novagen
• An expression vector can include a tag sequence.
• Tag sequences are typically expressed as a fusion with the encoded polypeptide. Such tags can be inserted anywhere within the polypeptide including at either the carboxyl or amino terminus. Examples of useful tags include, but are not limited to, green fluorescent protein (GFP), glutathione S-transferase (GST), polyhistidine, c- myc, hemagglutinin, FlagTM tag (Kodak, New Haven, CT), maltose E binding protein and protein A.
• GFP green fluorescent protein
• GST glutathione S-transferase
• polyhistidine polyhistidine
• c- myc hemagglutinin
• FlagTM tag Kodak, New Haven, CT
• a nucleic acid molecule encoding a Siglec-15 fusion polypeptide is present in a vector containing nucleic acids that encode one or more domains of an Ig heavy chain constant region, for example, an amino acid sequence corresponding to the hinge, C H 2 and C H 3 regions of a human immunoglobulin Oyl chain.
• Vectors containing nucleic acids to be expressed can be transferred into host cells.
• the term "host cell” is intended to include prokaryotic and eukaryotic cells into which a recombinant expression vector can be introduced.
• transformed and “transfected” encompass the introduction of a nucleic acid molecule (e.g., a vector) into a cell by one of a number of techniques. Although not limited to a particular technique, a number of these techniques are well established within the art.
• Prokaryotic cells can be transformed with nucleic acids by, for example, electroporation or calcium chloride mediated transformation.
• Nucleic acids can be transfected into mammalian cells by techniques including, for example, calcium phosphate co- precipitation, DEAE-dextran-mediated transfection, lipofection, electroporation, or microinjection.
• Host cells e.g., a prokaryotic cell or a eukaryotic cell such as a CHO cell
• the vectors described can be used to express Siglec-15 in cells.
• An exemplary vector includes, but is not limited to, an adenoviral vector.
• One approach includes nucleic acid transfer into primary cells in culture followed by autologous transplantation of the ex vivo transformed cells into the host, either systemically or into a particular organ or tissue.
• Ex vivo methods can include, for example, the steps of harvesting cells from a subject, culturing the cells, transducing them with an expression vector, and maintaining the cells under conditions suitable for expression of the encoded polypeptides. These methods are known in the art of molecular biology.
• the transduction step can be accomplished by any standard means used for ex vivo gene therapy, including, for example, calcium phosphate, lipofection, electroporation, viral infection, and biolistic gene transfer. Alternatively, liposomes or polymeric microparticles can be used. Cells that have been successfully transduced then can be selected, for example, for expression of the coding sequence or of a drug resistance gene. The cells then can be lethally irradiated (if desired) and injected or implanted into the subject. In one embodiment, expression vectors containing nucleic acids encoding fusion proteins are transfected into cells that are administered to a subject in need thereof.
• nucleic acid therapy can be accomplished by direct transfer of a functionally active DNA into mammalian somatic tissue or organ in vivo.
• nucleic acids encoding polypeptides disclosed herein can be administered directly to lymphoid tissues or tumors.
• lymphoid tissue specific targeting can be achieved using lymphoid tissue-specific transcriptional regulatory elements (TREs) such as a B lymphocyte-, T lymphocyte-, or dendritic cell-specific TRE. Lymphoid tissue specific TREs are known in the art.
• TREs lymphoid tissue-specific transcriptional regulatory elements
• Nucleic acids may also be administered in vivo by viral means.
• Nucleic acid molecules encoding fusion proteins may be packaged into retrovirus vectors using packaging cell lines that produce replication-defective retroviruses, as is well-known in the art.
• Other virus vectors may also be used, including recombinant adenoviruses and vaccinia virus, which can be rendered non- replicating.
• engineered bacteria may be used as vectors.
• Nucleic acids may also be delivered by other carriers, including liposomes, polymeric micro- and nanoparticles and polycations such as asialoglycoprotein/polylysine.
• liposomes polymeric micro- and nanoparticles and polycations
• polycations such as asialoglycoprotein/polylysine.
• physical means well-known in the art can be used for direct transfer of DNA, including administration of plasmid DNA and particle-bombardment mediated gene transfer.
• compositions including the disclosed Siglec-15-binding molecules are provided.
• Pharmaceutical compositions containing a Siglec-15- binding molecule can be for administration by parenteral (intramuscular, intraperitoneal, intravenous (IV) or subcutaneous injection), transdermal (either passively or using iontophoresis or electroporation), or transmucosal (nasal, vaginal, rectal, or sublingual) routes of administration or using bioerodible inserts and can be formulated in dosage forms appropriate for each route of administration.
• compositions disclosed herein are administered to a subject in a therapeutically effective amount.
• effective amount or “therapeutically effective amount” means a dosage sufficient to treat, inhibit, or alleviate one or more symptoms of the disorder being treated or to otherwise provide a desired pharmacologic and/or physiologic effect.
• the precise dosage will vary according to a variety of factors such as subject-dependent variables ⁇ e.g., age, immune system health, etc.), the disease, and the treatment being effected.
• the dosage administered to a patient is typically 0.01 mg/kg to 100 mg/kg of the patient's body weight.
• the dosage administered to a patient can be, for example, between 0.01 mg/kg and 20 mg/kg, 0.01 mg/kg and 10 mg/kg, 0.01 mg/kg and 5 mg/kg, 0.01 and 2 mg/kg, 0.01 and 1 mg/kg, 0.01 mg/kg and 0.75 mg/kg, 0.01 mg/kg and 0.5 mg/kg, 0.01 mg/kg to 0.25 mg/kg, 0.01 to 0.15 mg/kg, 0.01 to 0.10 mg/kg, 0.01 to 0.05 mg/kg, or 0.01 to 0.025 mg/kg of the patient's body weight.
• Exemplary specific dosages include, but are not limited to 0.2 mg/kg, 0.3 mg/kg, 1 mg/kg, 3 mg/kg, 6 mg/kg or 10 mg/kg.
• a dose as low as 0.01 mg/kg is believed to be suitable to have appreciable pharmacodynamic effects.
• Dose levels of 0.10-1 mg/kg are predicted to be most appropriate.
• human antibodies have a longer half-life within the human body than antibodies from other species due to the immune response to the foreign polypeptides. Thus, lower dosages of human antibodies and less frequent administration is often possible. Further, the dosage and frequency of administration of antibodies of the invention or fragments thereof may be reduced by enhancing uptake and tissue penetration of the antibodies by modifications such as, for example, lipidation.
• the Siglec-15-binding molecule is administered locally, for example by injection directly into a site to be treated.
• the injection causes an increased localized concentration of the Siglec-15-binding molecule composition which is greater than that which can be achieved by systemic administration.
• the Siglec-15-binding molecule compositions can be combined with a matrix as described below to assist in creating an increased localized concentration of the polypeptide compositions by reducing the passive diffusion of the polypeptides out of the site to be treated.
• compositions disclosed herein are administered in an aqueous solution, by parenteral injection or infusion.
• the formulation may also be in the form of a suspension or emulsion.
• pharmaceutical compositions are provided including effective amounts of a Siglec-15-binding molecule, and optionally include pharmaceutically acceptable diluents, preservatives, solubilizers, emulsifiers, adjuvants and/or carriers.
• compositions optionally include one or more for the following: diluents, sterile water, buffered saline of various buffer content (e.g., Tris-HCl, acetate, phosphate), pH and ionic strength; and additives such as detergents and solubilizing agents (e.g., TWEEN 20 (polysorbate-20), TWEEN 80
• polysorbate-80 polysorbate-80
• anti-oxidants e.g., ascorbic acid, sodium metabi sulfite
• preservatives e.g., Thimersol, benzyl alcohol
• bulking substances e.g., lactose, mannitol
• non-aqueous solvents or vehicles are propylene glycol, polyethylene glycol, vegetable oils, such as olive oil and corn oil, gelatin, and injectable organic esters such as ethyl oleate.
• the formulations may be lyophilized and redissolved/resuspended immediately before use.
• the formulation may be sterilized by, for example, filtration through a bacteria retaining filter, by incorporating sterilizing agents into the compositions, by irradiating the compositions, or by heating the compositions.
• Controlled Delivery Polymeric Matrices The Siglec-15-binding molecules disclosed herein can also be administered in controlled release formulations.
• Controlled release polymeric devices can be made for long term release systemically following implantation of a polymeric device (rod, cylinder, film, disk) or injection (microparticles).
• the matrix can be in the form of microparticles such as microspheres, where the agent is dispersed within a solid polymeric matrix or microcapsules, where the core is of a different material than the polymeric shell, and the peptide is dispersed or suspended in the core, which may be liquid or solid in nature.
• microcapsules are used interchangeably.
• the polymer may be cast as a thin slab or film, ranging from nanometers to four centimeters, a powder produced by grinding or other standard techniques, or even a gel such as a hydrogel.
• Either non-biodegradable or biodegradable matrices can be used for delivery of fusion polypeptides or nucleic acids encoding the fusion
• polypeptides may be natural or synthetic polymers. Synthetic polymers typically have a better characterization of degradation and release profiles. The polymer is selected based on the period over which release is desired. In some cases linear release may be most useful, although in others a pulse release or "bulk release” may provide more effective results.
• the polymer may be in the form of a hydrogel (typically in absorbing up to about 90% by weight of water), and can optionally be crosslinked with multivalent ions or polymers.
• the matrices can be formed by solvent evaporation, spray drying, solvent extraction and other methods known to those skilled in the art.
• Bioerodible microspheres can be prepared using any of the methods developed for making microspheres for drug delivery, for example, as described by Mathiowitz and Langer, J. Controlled Release , 5: 13-22 (1987); Mathiowitz, et al., Reactive Polymers, 6:275-283 (1987); and Mathiowitz, et al., J. Appl.
• the devices can be formulated for local release to treat the area of implantation or injection - which will typically deliver a dosage that is much less than the dosage for treatment of an entire body - or systemic delivery. These can be implanted or injected subcutaneously, into the muscle, fat, or swallowed.

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