Immunosuppressive activity of cepacidine A, a novel antifungal antibiotic produced by Pseudomonas cepacia

Abstract

Cepacidine A was first identified as a novel antifungal antibiotic which was isolated from the culture broth of Pseudomonas cepacia AF2001. It showed a potent in vitro antifungal activity against various pathogenic fungi, but did not show any activity against bacteria. Recently, the immunosuppressive action of cepacidine A was discovered using an in vitro screening system involving inhibition of the proliferation of murine lymphocytes stimulated by 2 mitogens, and also by in. vivo mouse models involving inhibition of delayed type hypersensitivity and SRBC hemagglutination. Cepacidine A showed a significant activity of cellular immunosuppression (ED50) at concentration levels of 1-3 mg/kg, i.p.. Unfortunately, the delayed toxicity at a dose of above 3 mg/kg i.p. was apparent.