Human anti-Gal immunoglobulin G antibody (Anti-Gal IgG)

Human anti-Gal IgG antibodies are the most abundant naturally occurring antibodies in humans, constituting approximately 1% of circulating IgG (Galili, 2013, PMID: 23335956). They specifically target the alpha-gal epitope (Gal-alpha-1,3-Gal-beta-1,4-GlcNAc-R), which is expressed in non-primate mammals but absent in humans due to the evolutionary inactivation of the GGTA1 gene (Machado et al., 2021, PMID: 33806344). These antibodies are the primary mediators of hyperacute rejection in xenotransplantation, as they bind to alpha-gal epitopes on donor organs and trigger rapid complement-mediated destruction (Cooper et al., 2015, PMID: 25911131). In therapeutic contexts, anti-Gal is targeted for neutralization using soluble alpha-gal conjugates like GAS914 to facilitate xenograft survival (Katopodis et al., 2002, PMID: 12163523). Conversely, researchers are harnessing these antibodies for cancer immunotherapy by modifying tumor cells with alpha-gal epitopes to promote their uptake by antigen-presenting cells and stimulate a systemic anti-tumor immune response (Galili, 2023, PMID: 37048954). Additionally, the interaction between these antibodies and alpha-gal-containing allergens is central to alpha-gal syndrome, a delayed allergic reaction to red meat (Commins et al., 2011, PMID: 21453908).

Other names

Anti-alpha-gal antibodyAnti-GalAnti-Gal alpha 1-3Gal antibodyNatural anti-Gal antibody

Therapeutic interventions either neutralize anti-Gal antibodies using soluble alpha-gal mimetics to prevent xenograft rejection or utilize the antibodies to target specific cells by introducing alpha-gal epitopes, thereby inducing opsonization and complement-dependent cytotoxicity.