Complement activation in SCID and nude mice is related to severity of tissue inflammation in the Candida mastitis model

A small animal model of localised candidiasis is needed for the evaluation of new antifungal compounds. Mammary glands of immunocompetent (BALB/cJ) an d immunodeficient (SCID and athymic nude) mice were infected with a wild-ty pe of Candida albicans. Some of the animals were treated with amphotericin B (AmB) while others were treated with saline and acted as controls. The hi stologic changes of infected mammary gland tissues and a number of other or gans were evaluated. Complement (C) activation was analysed by immunoelectr ophoretic quantification of molecules with C3c epitopes (C3, C3b, iC3b, and C3c) in serum. In all animals the organisms were confined to the mammary g lands. Serum C3c levels were significantly higher (P < 0.05) in infected un treated BALB/cJ and SCID mice, which also had severe mammary gland tissue i nflammation, compared with control mice treated with AmB (4 mg kg(-1) i.p. once daily for 4 days). Both treated and control nude mice showed less tiss ue inflammation compared to BALB/cJ and SCID mice, and revealed insignifica nt activation of the complement system. It is concluded that innate immune response is important in the control of candidiasis and that the murine mas titis model is useful for immunopathological studies as well as evaluation of potential antifungal compounds. (C) 2000 Federation of European Microbio logical Societies. Published by Elsevier Science B.V. All rights reserved.