FITC Mouse Anti-Rat CD32 Antibody (S-4246)

CD32, also known as FcγRII, is a critical class of low-affinity IgG receptors in the immune system. It is a member of the immunoglobulin superfamily, with its extracellular region consisting of two Ig-like domains that are primarily responsible for recognizing and binding the Fc fragment of immunoglobulin G (IgG), particularly exhibiting high affinity for IgG immune complexes. This protein is widely expressed on various immune cells, including B cells, monocytes, macrophages, neutrophils, and platelets. CD32 is a highly diverse family, encoded by three genes (FCGR2A, FCGR2B, FCGR2C) and generating multiple isoforms through alternative splicing. These isoforms can even have opposing functions: for instance, CD32A (FcγRIIA) contains an immunoreceptor tyrosine-based activation motif (ITAM) in its cytoplasmic tail, mediating activating signals such as phagocytosis and antibody-dependent cell-mediated cytotoxicity (ADCC); whereas CD32B (FcγRIIB) contains an inhibitory motif (ITIM), which negatively regulates B-cell activation and dampens immune responses to prevent overreaction. This delicate balance between "activating" and "inhibitory" signals positions CD32 as a central player in maintaining immune homeostasis, clearing pathogens, and modulating autoimmune responses.