CD64 reacts with the Fc gamma receptor 1 (FcγR1), a glycoprotein with a molecular weight of 72 kDa. The antigen is a high-affinity receptor for IgG and is able to bind human IgG1 and IgG3. The antigen is expressed on macrophages, monocytes, and interferon γ (IFN-γ) and Granulocyte Colony Stimulating Factor (G-CSF) stimulated neutrophils.
Antigen distribution: This antibody binds to a CD64 epitope distinct from the ligand-binding site and from the clone 32.2 antibody to CD64 epitope. It shows especially high affinity binding to human mononuclear phagocytes and polymorphonuclear leukocytes exposed to IFN-γ or G-CSF. Its binding is not blocked in the presence of human IgG or immune complexes. Cellular Expression: Fc gamma receptor 1 on macrophages, monocytes and neutrophils.