Growth inhibition of Candida by human oral epithelial cells.

Oropharyngeal candidiasis (OPC) caused by Candida albicans is a significant problem in human immunodeficiency virus (HIV)-infected persons. Recognizing the paucity of information on innate and/or adaptive mucosal host defenses against C. albicans, we recently reported that human and nonhuman primate and mouse vaginal epithelial cells inhibit the growth of C. albicans in vitro. In the present study, oral epithelial cells collected from saliva of healthy volunteers and a purified oral epithelial cell line were found to inhibit blastoconidia and/or hyphal growth of several Candida species. Cell contact was a strict requirement for the epithelial cell anti-Candida activity; neither saliva nor culture supernatants alone inhibited Candida growth, and addition of saliva to the coculture did not modulate the epithelial cell activity. Finally, epithelial cell anti-Candida activity was significantly lower in HIV-infected persons with OPC. Together, these results suggest that oral epithelial cells may play a role in innate resistance against OPC.