Immunoglobulin gamma 1 Fc region (IgG1 Fc) (IgG1 Fc)

The Immunoglobulin gamma 1 (IgG1) Fc region is the C-terminal portion of the IgG1 antibody, consisting of the CH2 and CH3 constant domains (Vidarsson G, et al. Front Immunol. 2014). It serves as the primary interface between the adaptive immune system and innate effector mechanisms by binding to Fc gamma receptors (FcγRs) on leukocytes (Wang TT, et al. Annu Rev Immunol. 2019). This interaction facilitates antibody-dependent cellular cytotoxicity (ADCC) and phagocytosis, which are essential for clearing pathogens and tumor cells. Furthermore, the Fc region binds to the neonatal Fc receptor (FcRn) in a pH-dependent manner, a process that protects the antibody from lysosomal degradation and extends its half-life in circulation to approximately three weeks (Roopenian DC, et al. Nat Rev Immunol. 2007). In biotechnology, the IgG1 Fc region is frequently engineered to modulate these effector functions or to create Fc-fusion proteins that benefit from its stability. In the context of autoimmune diseases, the IgG1 Fc-FcRn pathway is targeted by novel therapeutics like efgartigimod to accelerate the clearance of pathogenic autoantibodies (Gable K, et al. Neurotherapeutics. 2022).

Other names

Fc fragment of IgG1Fragment crystallizable region of IgG1IgG1 Fc domainImmunoglobulin G1 Fc

Modulation of Fc-mediated effector functions and competitive inhibition of the neonatal Fc receptor (FcRn) to regulate IgG1 serum concentrations.