Low affinity immunoglobulin gamma Fc region receptor II (CD32) (FcγRII)

Low affinity immunoglobulin gamma Fc region receptor II (FcγRII), or CD32, is a critical cell surface receptor found on various immune cells, including immature dendritic cells (UniProt P12318, P31994). On these cells, FcγRII exists in multiple isoforms, most notably the activating FcγRIIa and the inhibitory FcγRIIb, which together regulate the uptake of IgG-coated antigens and the subsequent maturation of the dendritic cell (PMID: 15549130). The interaction between immune complexes and these receptors dictates whether the dendritic cell will initiate a pro-inflammatory T-cell response or maintain peripheral tolerance (PMID: 21670304). Dysfunctional FcγRII signaling is heavily implicated in the pathogenesis of autoimmune diseases like systemic lupus erythematosus and the evasion of immune surveillance by tumors (PubMed: 26336149). Consequently, FcγRII is a major therapeutic target, with drugs like IVIG or engineered antibodies designed to either enhance its inhibitory function for treating inflammation or block it to improve the efficacy of monoclonal antibody therapies in oncology (PMID: 25244198). In the context of immature dendritic cells, targeting FcγRIIb is particularly significant for inducing antigen-specific tolerance or preventing premature activation in vaccine delivery systems.

Other names

CD32FCGR2Fc-gamma RIIFc-gamma receptor IICD32aCD32b

Modulation of immune cell activation and maturation through the balance of immunoreceptor tyrosine-based activation motifs (ITAM) and inhibitory motifs (ITIM) upon binding the Fc portion of IgG (PMID: 21670304).