Antigen-presenting cell receptors recognizing alpha-galactosyl epitopes

Antigen-presenting cell receptors recognizing alpha-galactosyl epitopes refers to a functional group of receptors, primarily Fc gamma receptors (FcγRs) and Complement receptors (CRs), that facilitate the uptake of antigens opsonized by natural anti-Gal antibodies. The alpha-gal epitope (Galα1-3Galβ1-4GlcNAc-R) is a carbohydrate structure found in most mammals but absent in humans, who instead produce high levels of natural anti-Gal antibodies due to exposure to gut flora. In therapeutic applications, such as cancer vaccines or intratumoral immunotherapies, antigens are engineered to express alpha-gal epitopes to recruit these natural antibodies. The resulting immune complexes bridge the antigen to FcγRs (such as CD16, CD32, and CD64) and Complement receptors (such as CR1 and CR3) on dendritic cells and macrophages. This interaction promotes robust phagocytosis, maturation of the antigen-presenting cells, and efficient cross-presentation of the antigens to T cells, thereby inducing a potent adaptive immune response against tumors or pathogens.

Other names

Fc gamma receptorsFcγRComplement receptorsCR1CR3CD16CD32CD64anti-Gal-mediated targeting receptors

Opsonization of alpha-gal-expressing antigens by natural anti-Gal antibodies, followed by binding of the antibody Fc portion to Fc gamma receptors on APCs, leading to enhanced antigen uptake and presentation.