FcγRII, also known as CD32, is a low affinity IgG Fc receptor. There are three distinct genes encoded (A, B, C) in humans and a single gene in mice. FcγRIIA, also known as CD32a, is an immunoglobulin superfamily member.FcγRIIA consists of an extracellular domain, a transmembrane region and a cytoplasmic tail containing a non-classical ITAM, which appears to be required for FcγRIIA dimerization and downstream intracellular signaling. FcγRIIA is the most widespread activating Fc receptor and it is expressed on monocytes/macrophages, granulocytes, platelets and mast cells in humans. Engagement of FcγRIIA and IgG induces inflammatory reactions and they are involved in the pathophysiology of several diseases, such as thrombocytopenia, rheumatoid arthritis and systemic lupus erythematosus. FcγRIIA is the only FcR expressed on platelets and cross-linking of FcγRIIA by antibodies activates platelets for aggregation and secretion. Unlike FcγRI and FcγRIIIA, the expression and phagocytic activity of FcγRIIA is independent of the Fc γ-chain. ?It has been reported that FcγRIIA associates with lipid rafts which regulates its ligand binding activity. The affinities of FcγRIIA for different IgG subclasses vary. In addition, R167H polymorphism affects the binding affinity of FcγRIIA to IgG2, but hardly affects the affinity for IgG1, IgG3, and IgG4. It has been reported that FcγRIIA is highly induced in HIV-infected quiescent CD4 T cells, serving as a biomarker.
Size
100 μg
Concentration
n/a
Applications
BA
Other Names
Low affinity immunoglobulin gamma Fc region receptor II-A, Fc fragment of IgG receptor IIa, IgG Fc receptor II-a, CDw32, Fc-gamma RII-a, FcγRII-a, FcRII-a, CD32a, FCGR2A