Abstract: Immunotherapeutic proteins comprising at least one heavy chain polypeptide derived from an IgG2 antibody are disclosed, wherein the heavy chain polypeptide comprises at least constant heavy domains 2 and 3 (CH2 and CH3) and the lower hinge, and the sequence of the lower hinge comprises a mutation enabling the immunotherapeutic protein to bind to and/or activate Fc?RIIb. The immunotherapeutic protein is suitable for use in methods of treating diseases or conditions wherein, for example, the activation of Fc?RIIb (ie for recruitment of the inhibitory functions of Fc?RIIb) is beneficial, such as allergic diseases.

Abstract: The present disclosure relates to the use of an at least one soluble Fc binding multimer comprising at least two Fc binding regions to assess FcR binding activity of an at least one polypeptide comprising an Fc region or fragment thereof, including an antibody, and methods and assays of using the Fc binding multimer to assess FcR binding activity. The FcR binding multimer may be a fusion polypeptide comprising an at least two Fc binding regions, or may consist of at least two peptides each comprising at least one Fc binding region, that are covalently or non-covalently oligomerised.

Abstract: A soluble multimeric protein or polypeptide is disclosed that is able to inhibit interaction of leukocyte Fc? receptors (Fc?R) and immunoglobulin G (IgG). The protein or polypeptide comprises two or more linked Fc binding regions, at least one of which is derived from an Fc?R type receptor and, particularly, Fc?RIIa. Also described are polynucleotide molecules encoding the protein or polypeptide and the use thereof in methods of treating a subject for an immune-complex (IC)-mediated inflammatory disease.

Abstract: A soluble multimeric protein or polypeptide is disclosed that is able to inhibit interaction of leukocyte Fc? receptors (Fc?R) and immunoglobulin G (IgG). The protein or polypeptide comprises two or more linked Fc binding regions, at least one of which is derived from an Fc?R type receptor and, particularly, Fc?RIIa. Also described are polynucleotide molecules encoding the protein or polypeptide and the use thereof in methods of treating a subject for an immune-complex (IC)-mediated inflammatory disease.

Abstract: The present invention provides a Fc?RIIa transgenic non-human animal model for autoimmune disease, particularly arthritis. This invention also provides a method of using this model to screen compounds that can reduce aberrant immune activity including aberrant immune complex formation aberrant immune complex clearance and immune complex induced inflammation. This invention also provides means of using this model to treat or prevent autoimmune disease.

Abstract: The present invention generally relates to molecules having Fc binding ability such as those with Fc receptor-like activity. The present invention also relates to the molecules, nucleic acids encoding the molecules, antagonist compounds, pharmaceutical compositions comprising the molecules and compounds, methods for testing potential antagonists, methods for producing the polypeptides, methods of treatment of disease and other aspects.