Binding molecules specific for FcγRIIA and uses thereof
The disclosure provides FcγRIIA-binding molecules, for example, humanized monoclonal antibodies capable of inhibiting FcγRIIA activity, and methods of using the FcγRIIA binding molecules, for example, in treating or preventing inflammatory, immune-mediated, or autoimmune diseases or disorders.
1. An isolated binding molecule that specifically binds to FcγRIIA, wherein the binding molecule comprises:
(i) a heavy chain variable (VH) region comprising a VH-complementarity determining region (CDR)1 comprising SEQ ID NO: 29, VH-CDR2 comprising SEQ ID NO: 19, and VH-CDR3 comprising SEQ ID NO: 30; and
(ii) a light chain variable (VL) region comprising a VL-CDR1 comprising SEQ ID NO: 22, VL-CDR2 comprising SEQ ID NO: 31, and VL-CDR3 comprising SEQ ID NO: 32.
2. The binding molecule of claim 1 , wherein the VH region and VL region comprise the amino acid sequences of SEQ ID NO: 33 and SEQ ID NO: 34, respectively.
3. The binding molecule of claim 1 , which is selected from a murine antibody, a humanized antibody, a chimeric antibody, a monoclonal antibody, a polyclonal antibody, a recombinant antibody, a bi-specific antibody, a multi-specific antibody, an Fv, an Fab, an F(ab′)2, an Fab′, a dsFv fragment, a single chain Fv (scFV), an sc(Fv)2, a disulfide-linked (dsFv), a diabody, a triabody, a tetrabody, a minibody, or a single chain antibody.
4. The binding molecule of claim 1 , comprising a human immunoglobulin G (IgG) constant region.
5. The binding molecule of claim 4 , wherein the constant region comprises amino acid substitutions at Kabat positions 234, 235, and 331, wherein:
a. the amino acid at Kabat position 234 is substituted with Phenylalanine (F),
b. the amino acid at Kabat position 235 is substituted with Glutamic acid (E), and
c. the amino acid at Kabat position 331 is substituted with Serine (S).
6. The binding molecule of claim 4 , wherein the constant region comprises amino acid substitutions at Kabat positions 252, 254, and 256, wherein:
a. the amino acid at Kabat position 252 is substituted with Tyrosine (Y),
b. the amino acid at Kabat position 254 is substituted with Threonine (T), and
c. the amino acid at Kabat position 256 is substituted with Glutamic acid (E).
7. The binding molecule of claim 1 , which is conjugated to an agent selected from the group consisting of an antimicrobial agent, a therapeutic agent, a prodrug, a peptide, a protein, an enzyme, a lipid, a biological response modifier, a pharmaceutical agent, a lymphokine, a heterologous antibody or fragment thereof, a detectable label, a polyethylene glycol (PEG), a toxin, and a combination of two or more of any said agents.
8. A composition comprising the binding molecule of claim 1 and a carrier.
9. A method for inhibiting ribonucleoprotein-immune complex (RNP-IC)-mediated type I IFNα in a peripheral blood mononuclear cell (PBMC), the method comprising contacting the PBMC with the binding molecule of claim 1 .
10. A method for inhibiting anti-neutrophil cytoplasmic antibody (ANCA)-induced neutrophil activation, the method comprising contacting a neutrophil with the binding molecule of claim 1 .
11. A method of treating or preventing an inflammatory, immune-mediated, or autoimmune disease or disorder in a subject, the method comprising administering to a subject in need of treatment an effective amount of the binding molecule of claim 1 .
12. The method of claim 11 , wherein the disease or disorder is ANCA-associated vasculitis (AAV), systemic lupus erythematosus (SLE), lupus nephritis, membranous nephritis, giant cell arteritis (GCA) vasculitis, immune thrombocytopenia (ITP), rheumatoid arthritis, polymyositis, dermatomyositis, pemphigus, hemolytic anemia, mixed connective tissue disease, Sjögren's syndrome, scleroderma, an autoantibody disorder, an immune-complex-mediated disorder, ADA-mediated adverse effects, NETosis, and NETosis-associated disorders, including sepsis, thrombosis, acute kidney injury, acute lung injury, chronic obstructive pulmonary disease, glomerulonephritis, toxic liver injury, stroke, atherogenesis, Type I diabetes, and IgG mediated hypersensitive reaction.
13. A method for detecting FcγRIIA in a sample, the method comprising (a) contacting the sample with the binding molecule of claim 1 , and (b) detecting binding of the binding molecule to FcγRIIA, thereby detecting FcγRIIA in the sample.