Immunoglobulin G Fc gamma receptor (FcγR (or IgG FcγR))

Immunoglobulin G Fc gamma receptors (FcγRs) are a family of cell surface receptors that bind the Fc region of IgG antibodies, playing a critical role in linking humoral and cellular immunity[2][4][5]. FcγRs are classified into several types—including the high-affinity FcγRI (CD64), and the low-to-intermediate affinity FcγRII (CD32) and FcγRIII (CD16)—each with distinct affinities, cellular distribution, and signaling properties[2][7]. They mediate antibody-dependent functions such as phagocytosis, ADCC, degranulation, antigen presentation, and cytokine production, using immunoreceptor tyrosine-based activation or inhibition motifs (ITAM/ITIM) in their cytoplasmic domains or associated accessory chains[2][4][5]. Differential binding of IgG subclasses and polymorphic variants of FcγRs influences clinical responses to monoclonal antibody therapies and susceptibility to autoimmune or infectious diseases[6][7]. FcγRs are key therapeutic targets in immuno-oncology and autoimmunity, both as mediators of antibody efficacy and as direct drug targets in efforts to enhance or modulate immune cell function[1][3][6].

Other names

Fc gamma receptorIgG Fc receptorFcγ receptorCD64 (FcγRI)CD32 (FcγRII)CD16 (FcγRIII)

Engagement of Fc region of IgG antibodies leading to activation of effector immune cells. Initiation of phagocytosis via ITAM signaling. Triggering ADCC and degranulation in NK cells and other effector cells. Modulation of cytokine secretion and inflammatory mediator release.