Fc receptor for immunoglobulin (FcR)

Fc receptors are a family of cell surface glycoproteins expressed primarily on immune effector cells (such as macrophages, neutrophils, NK cells, and some B cells) that bind the Fc region of immunoglobulin molecules (IgG, IgA, IgE, IgM, and IgD)[1][4][5]. Engagement of Fc receptors by antibody-bound targets connects humoral antibody recognition to diverse cellular immune responses, including phagocytosis, antibody-dependent cellular cytotoxicity (ADCC), release of inflammatory mediators, and modulation of cytokine signaling. Fc receptors are classified by the immunoglobulin isotype they bind and by structural/functional characteristics, with the principal groups being FcγRs (for IgG), FcαRs (for IgA), and FcεRs (for IgE)[1][4][5]. Key subtypes include FcγRI (CD64), FcγRII (CD32), and FcγRIII (CD16), among others. Genetic polymorphisms and variations in these receptors are linked to differences in immune response, susceptibility to autoimmune diseases, and the efficacy of antibody-based therapies[1][2][5]. Note: To extract a specific "canonical name," further specification of the subclass (e.g., Fc gamma receptor IIIa) is required. "Effector cell Fc receptor" is a general functional description, not a unique molecular target.

Other names

Fc receptorFcRFc gamma receptor (FcγR)Fc alpha receptor (FcαR)Fc epsilon receptor (FcεR)CD64/CD32/CD16 for gamma subtypesCD89 for alphaCD23/CD117 for epsilon

Mediates effector functions of therapeutic antibodies via IgG Fc region—promotes phagocytosis and ADCC by engaging immune cell FcγRs[1][6] Can inhibit or modulate immune response depending on activating vs. inhibitory receptor engaged (ITAM vs ITIM signaling motifs)[1][2][5]