Analysis of autoantibodies to glycolipids on thymocytes in New Zealand black mice.

Carbohydrate specificities of thymocyte cytotoxic autoantibodies in New Zealand Black (NZB) mice were examined using liposome immune lysis assay (LILA) system. NZB mice progressively produced antibodies to nine neutral glycolipids and two gangliosides tested by 10 months of age. Such increases were not detected in normal BALB/c and CBA/J mice. Among these antibodies, antibodies to ceramide monohexoside (CMH), ceramide dihexoside (CDH), paragloboside (PG), ceramide pentahexoside (CPH), asialo GM1 (GA1), asialo GM2 (GA2), GM4 and GM2 in the plasma of NZB mice were absorbed by single cell suspensions of autologous untreated as well as protease-treated thymocytes. In contrast, antibodies to ceramide trihexoside (CTH), globoside (Glo), and Forssman antigen (For) were not absorbed by these cells. Analysis of glycolipid compositions of young NZB thymocytes demonstrated that strict correlation was observed between the presence of glycolipids on thymocytes and absorbing pattern of anti-glycolipid antibodies by thymocytes. These data indicate that anti-carbohydrate antibodies with thymocyte binding capacity in NZB mice mainly recognize sugar portions of glycolipids rather than glycoproteins on thymocytes. The failure to find such carbohydrate specific antibodies in some normal strains of mice suggested that these antibodies may be important for subsequent immunologic abnormalities in NZB mice.