FCGR2A/CD32a

FCGR2A (CD32a) is the broadly expressed, activating member of the FcγRII/CD32 family. It is a low-affinity receptor for the Fc region of IgG, found on monocytes, macrophages, dendritic cells, neutrophils, eosinophils and platelets. CD32a signals through an intrinsic ITAM in its cytoplasmic tail, recruiting SYK to trigger phagocytosis of immune complexes, antibody-dependent cellular cytotoxicity, cytokine release and inflammatory responses. A common H131R polymorphism alters binding to human IgG2 and influences susceptibility to infections and autoimmune diseases. On platelets, CD32a mediates heparin-induced thrombocytopenia triggered by anti-PF4/heparin antibodies. CD32a engagement is also a key design consideration for therapeutic antibodies that rely on myeloid effector functions.