17-beta-estradiol upregulates the stress response in Candida albicans: implications for microbial virulence.

OBJECTIVE The influence of 17-beta-estradiol on the stress response of Candida albicans was studied. METHODS The survival of clinical isolates of C. albicans treated with 17-beta-estradiol after heat and oxidative stress was measured by viable plate counts. Cellular proteins were analyzed via SDS-PAGE. RESULTS The heat stress response induced by 17-beta-estradiol in C. albicans grown at 25 degrees C protected the organisms against the lethal temperature of 48.5 degrees C, as shown by viable plate counts. 17-beta-estradiol also enhanced protection of C. albicans against oxidative stress (menadione exposure). SDS-PAGE analysis of cytoplasmic extracts revealed proteins induced by 17-beta-estradiol were similar to those induced by heat. CONCLUSION 17-beta-estradiol enhances survival of C. albicans under heat and oxidative stresses. The proteins induced by 17-beta-estradiol are probably heat shock proteins. Because heat shock proteins are considered to be virulence factors, 17-beta-estradiol may function to promote in vivo survival.