Lack of suppression by gangliosides of humoral or cellular immunity in vivo.
Gangliosides inhibit the proliferative responses of murine and human lymphocytes in vitro, and it has been suggested that they are immunosuppressive in vivo, although no in vivo studies have been performed. In view of the use of gangliosides to treat patients with a variety of neurological disorders, experiments were undertaken to evaluate the possible immunomodulatory effects of gangliosides in vivo. BALB/c mice were injected 5 days a week with buffer, mixed brain gangliosides, or GM1 ganglioside at dosage levels of 30 mg/kg, 60 mg/kg or 90 mg/kg. After 30 days of treatment, the mice were immunized with keyhole limpet hemocyanin or pneumococcal type III polysaccharide and the ganglioside treatment was continued. No differences between treated and control groups were noted in either the magnitude or duration of the antibody response. No differences between groups were noted in the proliferative responses of splenic mononuclear cells to concanavalin A or allogeneic antigens after 9-10 weeks of treatment, nor in the generation of cytotoxic effector cells after 90 days of treatment. Thus, despite the well-documented immunosuppressive effects of gangliosides in vitro, no evidence for a suppressive effect on humoral or cellular immunity in vivo was obtained in these studies.