Immunopharmacological study of sulfated schizophyllan (SPG). I.--Its action as a mitogen and anti-HIV agent.

Sulfated schizophyllans of differing sulfur content were prepared and their mitogenic activities and effects on human immunodeficiency virus (HIV) were investigated in vitro. The sulfated schizophyllans were found to possess mitogenic activity. Anti-viral activity was evaluated in terms of cytopathic effect, and by the fluorescence antibody technique, reverse transcriptase assay and cell proliferation assay. Schizophyllans with a higher sulfur content showed potent anti-HIV effects on Molt-4 clone No. 8 or MT-4 cells infected with HIV as well as on lymphocytes from AIDS patients. It is suggested that the sulfur content of schizophyllans is the most important factor for inhibiting growth of HIV, rather than molecular weight or kinds of sugar component. Thus, sulfated schizophyllans appear applicable as anti-HIV drugs.