Study Of Vaginal Epithelial Cell Anti-Candida Activity And The Mechanism Of It

Vulvovaginal candidiasis (VVC) is a common mucosal infection affecting significant numbers of women in their reproductive years. Although no life threaten to the patients as system candidiasis has, it's morbidity and recurrence is very high. Approximately 75% of all women experience at least one episode of VVC during their lifetime. Up to 5% of women will subsequently develop recurrent VVC (RVVC) with no known predisposing factors. Antifungal therapy, while highly effective, but does not prevent subsequent recurrence for individual attacks of VVC. Moreover, it's use is defined due to its resistance and side-effect. It is not suitable to susceptible women of asymptomatic carriers or in susceptible period to prevent VVC. How to decrease the morbidity and recurrence in microecological way is to be resolved. Candida is a commensal organism. If we can understand the mechanisms of allowing the organism to just colonize but not invade and cause syndrome, it will provide us some clues to explore new ways to prevent the disease. Innate and adaptive cell mediate immunity are considered to be the predominant host defense mechanism against vaginal Candida infections. Estrogen is an important factor in susceptibility to Candida albicans vaginitis. In this research we will study the innate immune defense of vaginal: growth inhibition of C.albicans mediated by vaginal epithelial cells and investigate the mechanism of the anti-Candida activity.Try to study the role of estrogen in the susceptibility to VVC.Part one Anti-Candida Activity Mediated by Vaginal Epithelial Cells from Mice And the Effect of Estrogen on ItMethods: C57BL / 6J mice vaginae from estrogen treatment group, diestrus group and ovariectomized group were excised respectively. The vaginae were dissociated into single cell suspension by dispase and collagenase I. Immunohistochemical analyse of the separated cells demonstrated that over 80% were vaginal epithelial cells. The epithelial enriched cells were used as effector cells. Stationary-phase blastoconidia of C. albicans strains ATCC 90028 was used as target cells. After 9h coincubation of effector(E) with target(T) at various ratios, C. albicans growth density was observed by upside-down microscopy. The incorporated ³H-glucose were measured by liquid scintillation and the percent growth inhibition of C. albicans was calculated. The ultra-structural changes were observed by transmission electron microscopy.Results After 9h coincubation of effector cells with target cells, growth density of C. albicans was visibly reduced and it's growth activity was inhibited. Compared to ovariectomized group and diestrus group, epithelial cells from estrogen-treated mice had less ability to inhibit the growth of C. albicans (P<0.05). C. albicans incubated alone showed intact and legible ultrastructure while coincubated Candida showed obvious changes: the cell wall ruptured, intact cytoplasmic membrane were damaged, intracellar component dissolved, organellae swollen and even dissolved.Part two Potential Mechanism of Anti-Candida Activity Mediated by Mice Vaginal Epithelial CellsMethods Vaginae from diestrus C57BL / 6J mice were dissociated into single cell suspension with dispase and collagenase I . The effects of mannan, periodic acid and EGTA on the ability of vaginal epithelial cells to bind Candida albicans cells werestudied by flow cytometric analysis and fluorescence microscopy. The incorpotated ³H-glucose was measured by liquid scintillation to determine the effect of the three factors on the anti-Candida activity mediated by vaginal epithelial cells. Nitric oxide levels in supernatant of culture of effect cell and target cell and coculture were assayed by nitric oxide assay kit.Results The addition of 3mg per ml mannan produced a significant decrease in the number of vaginal epithelial cells that bound FITC-positive Candida compared with PBS alone[ (4.47 ± 1.89) % vs (14.16 ± 2.17) %, P<0.05]. Although treatment of the cells with mannan increased the epithelial cell anti-Candida activity compared to cells treated wit...