Liposome Agglutination and Liposomal Membrane Immune-Damage Assays for the Characterization of Antibodies to Glycosphingolipids

Abstract

Antibodies against each of three neutral glycosphingolipids, Forssman glycolipid, globoside I, and asialo G_M2, 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 G_M2 antibodies reacted only with Forssman glycolipid and asialo G_M2, respectively, but purified anti-globoside I antibodies cross-reacted with asialo G_M2.