Induction of human defensins by intestinal Caco-2 cells after interactions with opportunistic Candida species.

In this study we investigated the effects of Candida albicans, Candida krusei, Candida tropicalis and Candida parapsilosis on human beta-defensin 2 (HBD-2) production in Caco-2 intestinal cell line, and the production of alpha-defensins (human neutrophil peptides, HNP 1-3) in peripheral blood. Opportunistic pathogen yeasts can modulate the host immune function by inducing defensins, the natural antimicrobial peptides. Here we show that Candida spp. stimulated HBD-2 expression in and release from Caco-2 cells, with C. albicans inducing the highest levels of HBD-2. Similarly, HNP 1-3 secretion was significantly increased in whole blood after exposure to Candida yeast cells, with C. albicans producing the greatest effect. Our investigations underscore the important role of beta and alpha defensins produced by intestinal epithelial cells locally and neutrophils systemically in the antifungal defense against Candida.