An immunosuppressive factor interacts with membrane glycolipid asialo-GM1 structure.

An immunosuppressive factor was isolated from sheep-erythrocyte hyperimmunized mouse serum. Possibilities of the adsorption of the immunosuppressive factor with glycolipid asialo-GM1 incorporated liposome (dipalmitoyl lecithin) and the blockade of immunosuppressive activity by specific anti-asialo-GM1 incorporated antibody were tested. We report here that: The immunosuppressive activity of the immunosuppressive factor decreased quantitatively if the factor was preincubated with asialo-GM1 incorporated liposome (GALP) as compared with that preincubated with liposome (LP) alone; and the presence of specific anti-asialo-GM1 antibody is able to protect in vitro anti-sheep erythrocyte (SRBC) response from the suppressive effect of the immunosuppressive factor in a dose-dependent fashion under similar cell culture condition. The results indicate that asialo-GM1 may be related to the receptor of immunosuppressive factor.