Liposome agglutination and liposomal membrane immune-damage assays for the characterization of antibodies to glycosphingolipids.

Antibodies against each of three neutral glycosphingolipids, Forssman glycolipid, globoside I, and asialo GM2, were elicited in rabbits. The specificity of these antibodies was studied by liposome agglutination and liposomal membrane immune-damage assays using liposomes prepared with each glycolipid hapten. Spectrophotometric measurement of liposome agglutination was found to be effective for detecting IgG antibodies, whereas complement-dependent immune-damage assay favored the expression of IgM antibodies. Three glycosphingolipids having the same non-reducing terminal N-acetylgalactosamine residues were discriminated with IgG antibodies, while IgM antibodies showed cross-reactivity. Specifically purified anti-Forssman and anti-asialo GM2 antibodies reacted only with Forssman glycolipid and asialo Gm2, respectively, but purified anti-globoside I antibodies cross-reacted with asialo GM2.