Species-specific inhibition by glycophorins of complement activation via the alternative pathway

Glycophorin, one of the major glycoproteins of erythrocytes (E), was extracted from human E (glycophorin-Hu) and guinea pig E (glycophorin-GP) and adsorbed to rabbit-E. The adsorption of glycophorin-Hu and glycophorin-GP to rabbit-E made the E resistant to hemolysis by human serum and guinea pig serum, respectively, via the alternative complement pathway (ACP). However, it did not make the rabbit-E resistant to hemolysis by serum heterologous to the glycophorin adsorbed. This species-specific inhibition by glycophorin of ACP activation should play a role in restricting ACP activation on self cell membranes. By recognizing the self-cell surface as the place where the complement reaction must be prevented, ACP will be able to accomplish the discrimination of non-self constituents without diversity of recognition sites for a variety of foreign substances.