Immunoglobulin gamma Fc receptor IIIa (CD16a (also written as FcγRIIIa))

Immunoglobulin gamma Fc receptor IIIa (CD16a) is a transmembrane receptor primarily expressed on natural killer (NK) cells, macrophages, and select neutrophils. It binds the Fc portion of immunoglobulin G (IgG) antibodies, mediating key immune effector functions such as antibody-dependent cell-mediated cytotoxicity (ADCC), in which NK cells kill antibody-coated target cells. Its structural organization includes an extracellular IgG-binding domain, a transmembrane region, and an intracellular segment involved in signaling via association with adaptor proteins containing immunoreceptor tyrosine-based activation motifs (ITAMs). Genetic variants in FCGR3A can modify IgG binding affinity and influence susceptibility to autoimmune and inflammatory diseases, affect response to monoclonal antibody therapies, and modulate disease progression. FcγRIIIa/CD16a is a prominent therapeutic target in oncology and immune modulation, particularly through the action of monoclonal antibodies that enlist innate immune cells for targeted cell killing[1][2][3][6].

Other names

Fc gamma receptor IIIaCD16aFcγRIIIaFcgamma receptor IIIaFCGR3ACD16-2

Antibody-dependent cell-mediated cytotoxicity (ADCC): drugs engage FcγRIIIa on NK cells, triggering targeted cell lysis through release of cytotoxic granules and cytokines[1][2][3]. Enhancement of phagocytosis and antigen clearance. Modulation of cytokine secretion.