Fc gamma receptor (pro-inflammatory type) (FcγR (activating))

Fc gamma receptors (FcγRs) are cell-surface receptors for the Fc portion of immunoglobulin G (IgG) and are subdivided into activating (pro-inflammatory) and inhibitory types. The pro-inflammatory (activating) FcγRs—including FcγRI (CD64), FcγRIIA (CD32A), and FcγRIIIA (CD16A)—mediate the recognition of IgG-coated targets such as pathogens or immune complexes and initiate a cascade of immune cell activation. These receptors signal primarily through immunoreceptor tyrosine-based activation motifs (ITAMs), leading to phagocytosis, the release of pro-inflammatory cytokines (e.g., TNF-α, IL-1β, IL-6), antigen presentation, and enhanced T cell polarization, especially toward Th1 and Th17 phenotypes[2][3][4][5][6][7][9]. They play a key role in immunity against infections but are also implicated in the pathology of inflammatory and autoimmune diseases, including rheumatoid arthritis. Pharmacological targeting of pro-inflammatory FcγRs by monoclonal antibodies or fragments has shown potential to ameliorate autoimmune inflammation but presents challenges such as risk of immunosuppression and cytokine release syndrome[5][7].

Other names

Activating Fc gamma receptorsFcγRs (activating)FcγRI (CD64)FcγRIIA (CD32A)FcγRIIIA (CD16A)activating IgG receptors

Antagonism: Antibody-mediated blockade of receptor function to reduce pro-inflammatory signaling Agonism: Immune complex-induced receptor clustering activates downstream pro-inflammatory pathways Modulation of ITAM/ITIM signaling for immune balance