SERUM IMMUNOGLOBULINS IN HEYMANNS EXPERIMENTAL NEPHRITIS MODULATE BINDING OF PROPERDIN AND FACTOR-H TO SULFO-GLYCOSPHINGOLIPIDS (IISO3(-)-S-3)-GG(3)CER AND (IIISO3(-)-S-3)-,(IISO3(-)-S-3)-GG(3)CER

The nephropathic effects of Heymann's experimental nephrites involve a utoallergic serum antibodies directed against rat kidney membrane cons tituents. In assessing the action of glycolipids as possible autoaller gens in these conditions, it was found that heterologous and autologou s Heymann's nephritis sera antibodies recognize the rat kidney sulphat ides, (IISO3(-)-S-3)-Gg(3)Cer(S(tri)1), and (IIISO3(-)-S-3)-,(IISO3(-) -S-3)-Gg(3)Cer(S(tri)2). Two antibody populations in Heymann's sera, e ach reacting with only one of the two sulphatides, could be observed. It was further shown that human factor-H and properdin, pivotal regula tors of the alternative pathway of complement activation, both bound t o S(tri)2 in vitro. This binding of factor-H and properdin was differe ntially affected by affinity-purified anti-S(tri)2 antibodies of Heyma nn's nephritis sera. Whereas the interaction between factor-H and S(tr i)2 was inhibited by the antibody, that of properdin was enhanced.