Cancer immunotherapy for pancreatic cancer utilizing α-gal epitope/natural anti-Gal antibody reaction

Figure 2 Reciprocal evolution of α1, 3 galactosyltransferase (α1, 3 GT) enzyme activity, α-gal epitopes, and anti-Gal antibody in mammals. α-gal epitopes have been synthesized in mammals by α1, 3 galactosyltransferase (α1, 3 GT) for more than 125 million years, since before the divergence of placental mammals and marsupials. All non-mammalian vertebrates lack α1, 3 GT and do not express α-gal epitopes. Expression of this epitope was suppressed in ancestral Old World primates after they diverged from New World monkeys, and probably after apes and monkeys diverged from each other. Suppression of α-gal epitopes was followed by production of natural anti-Gal antibody, which is absent in non-primate mammals, prosimians, and New World monkeys.