Growth inhibition of Candida albicans by vaginal cells from naïve mice

Recurrent vulvovaginal candidiasis (RVVC) is a common idiopathic mucosal infection caused by Candida albicans. Current data suggests that local immunity is more important than that in the peripheral circulation for protection against infection. In the present study, anti-Candida innate resistance at the vaginal mucosa was investigated using a murine model. For this, splenic and vaginal cells were assessed for in vitro growth inhibition (GI) of C. albicans and cytotoxicity of natural killer (NK) cell-sensitive tumour targets (YAC-1). As expected, significant GI of C. albicans by splenic cells was mediated predominantly by polymorphonuclear leucocytes (PMNL) at effector to target (E:T) ratios of 100 and 50:1. From the vaginal mucosa, naïve unfractionated, but not nylon wool non-adherent (NWN), cells extracted from whole vaginal tissue showed significant GI of C. albicans at E:T ratios as low as 1:1, but only modest killing of YAC-1 targets at all E:T ratios. Subsequent experiments showed significant GI of C. albicans by vaginal epithelioid-enriched cells and with several epithelial cell lines, but not in supernatants collected from the co-cultures. In contrast, lymphoid cell lines had no anti-Candida activity. These results suggest that anti-Candida activity is present at the vaginal mucosa, but unlike that from the spleen, the vaginal activity appears to be predominantly mediated by epithelial cells.