Galactose-alpha-1,3-galactose-modified tumor vasculature-associated antigens (α-Gal-TEC antigens)

The target "tumor endothelial cells expressing αGal-decorated vasculature-associated antigens" refers to a therapeutic strategy where tumor-associated blood vessels are engineered to express the Galactose-alpha-1,3-galactose (α-Gal) carbohydrate epitope. Humans naturally lack the α1,3-galactosyltransferase (αGT) enzyme required to synthesize this epitope and consequently possess high titers of natural anti-Gal antibodies, which constitute approximately 1% of circulating IgG (Galili, 2013). By using viral vectors or lipid nanoparticles to deliver the αGT gene (GGTA1) to the tumor microenvironment, the endothelial cells of the tumor vasculature are induced to display α-Gal on their surface glycoproteins and glycolipids (Deriy et al., 2005). This modification effectively "flags" the tumor's blood supply for destruction by the innate immune system. Upon expression, endogenous anti-Gal antibodies bind to the α-Gal epitopes, initiating complement-dependent cytotoxicity (CDC) and antibody-dependent cellular cytotoxicity (ADCC), which leads to the rapid collapse of the tumor's vascular network and subsequent tumor necrosis (Unfer et al., 2003). This approach is particularly attractive because it leverages a pre-existing, potent immune mechanism to selectively target the neo-vasculature of solid tumors while sparing normal tissues that do not express the α-Gal epitope.

Other names

Alpha-gal decorated tumor vasculatureα1,3-galactosyltransferase-modified endothelial antigensα-Gal epitopes on tumor endothelial cellsAnti-Gal targeted tumor vasculature

Induction of complement-dependent cytotoxicity (CDC) and antibody-dependent cellular cytotoxicity (ADCC) against tumor endothelial cells via binding of natural anti-Gal antibodies to α-Gal epitopes.