Immunochemical studies of infectious mononucleosis--XI. comparison of heterophile antibody inhibitors from the erythrocyte membranes of four mammalian species.

Immunochemical comparisons were made of the reactivity of membrane glycoproteins from horse, bovine, sheep and goat erythrocytes with heterophile antibodies of infectious mononucleosis. The four receptors were tested as competitive inhibitors of a sandwich-type solid-phase radioimmunoassay and of agglutination of glycoprotein-latex reagents by infectious mononucleosis serum. The results of this study showed that the bovine glycoprotein had a superior reactivity with this heterophile antibody system and sheep erythrocyte glycoprotein was the least reactive. The latter had negligible ability to displace 125I-bovine glycoprotein and was a very poor inhibitor of the agglutination of a bovine glycoprotein-latex reagent by infectious mononucleosis serum. Horse and goat glycoproteins were more efficient inhibitors than sheep glycoprotein but less active than the preparation from bovine red cells. All of the inhibitory activity of sheep, horse and goat glycoproteins, and a major portion of that of the bovine glycoprotein was destroyed by neuraminidase treatment. We have termed this receptor--shared by all four species--the Paul-Bunnell receptor, since by definition Paul-Bunnell antibody is a sheep erythrocyte agglutinin which is also reactive with horse, bovine and goat erythrocytes. The neuraminidase (and alkaline borohydride) resistant receptor of bovine glycoprotein has been designated the Bo receptor because it is not common to the other three species.