T-CELL SPECIFIC IMMUNOSUPPRESSION BY PRODIGIOSIN ISOLATED FROM SERRATIA-MARCESCENS

Prodigiosin was isolated from the culture broth of Serratia marcescens B-1231. This compound inhibited the T-cell mediated immune responses such, as concanavalin-A induced proliferation, mixed lymphocyte respon se, local graft vs host reaction and T-dependent antibody response at non-toxic concentrations. However, prodigiosin did not affect B-cell m ediated immune functions such as lipopolysaccharide-induced proliferat ion and -activated polyclonal antibody production at the same concentr ations. Prodigiosin did not cause death in vitro to lymphocytes at eff ective concentrations (<100 nM) and also did not show toxicity in vivo to lymphoid organs at effective dosages (10 and 30 mg/kg). The pharma cological potencies were comparable to the activities of other T-cell specific immunosuppressants such as cyclosporin A and FK-506. In concl usion, it might be suggested that prodigiosin could be used as an immu nosuppressant in clinical and immunological studies. (C) 1998 Internat ional Society for Immunopharmacology. Published by Elsevier Science Lt d. All rights reserved.