Vaginal T lymphocyte population kinetics during experimental vaginal candidosis: evidence for a possible role of CD8+ T cells in protection against vaginal candidosis

Vaginal candidosis represents a significant health problem to women of childbearing age worldwide. It has been postulated that localized T cells play a role in protection against vaginal candidosis. In an attempt to evaluate the role of vaginal T cells in protection against vaginal candidosis, T cell population kinetics was evaluated using an oestrogen-dependent vaginal candidosis murine model. Vaginal T lymphocytes were isolated at different time points post C. albicans inoculation, viable cells were enumerated, phenotypically analysed for the expression of CD3, CD4 and CD8 T cell markers and absolute numbers of T cell subsets were calculated. Oestrogen-induced persistence of vaginal candidosis resulted in a significant increase in the total number of vaginal lymphocytes within 24-48 h post infection; increased vaginal lymphocyte numbers persisted throughout the infection period. The number of CD3+ T cells dramatically increased following C. albicans administration and was maintained at high levels throughout the infection period. The majority of CD3+ T cells were of the CD8+ type; however, considerable numbers of both CD4+ T cells and CD4+CD8+ T cells were also observed throughout the infection period. The considerable and persistent increase in vaginal T cell numbers in general and that of CD8+ T cells in particular are evidence of the possible role played by localized T cells in protection against vaginal candidosis.