Anti-candida mucosal immunity

This study analyzes the phenotype of vaginal dendritic cells (VDCs), their antigenic presentation and activation of T-cell cytokine secretion, and their protective role in a rat model of Candida vaginitis. Histological observation demonstrated a significant accumulation of OX62+ VDCs in the mucosal epithelium of Candida albicans-infected rats at the third round of infection. We identified two subsets of OX62+ VDCs differing in the expression of CD4 molecule in both noninfected and Candida infected rats. The OX62+ CD4+ subset of VDCs displayed a lymphoid cell-like morphology and expressed the T-cell antigen CD5, whereas the OX62+ CD4-VDC subset exhibited a myeloid morphology and was CD5 negative. Candida infection resulted in VDC maturation with enhanced expression of CD80 and CD134L on both CD4+ and CD4- VDC subsets at 2 and 6 weeks after Candida infection. CD5- CD4- CD86- CD80- CD134L+ VDCs from infected, but not noninfected, rats spontaneously released large amounts of interleukin-12 (IL-12) and tumor necrosis factor alpha, whereas all VDC subsets released comparable levels of IL-10 and IL-2 cytokines. Furthermore, OX62+ VDCs from infected rats primed naive CD4+ T-cell proliferation and release of cytokines, including gamma interferon, IL-2, IL-6, and IL-10, in response to staphylococcal enterotoxin B stimulation in vitro. Adoptive transfer of highly purified OX62+ VDCs from infected rats induced a significant acceleration of fungal clearance compared with that in rats receiving naive VDCs, suggesting a protective role of VDCs in the anti-Candida mucosal immunity. Finally, VDC mediated protection was associated with their ability to rapidly migrate to the vaginal mucosa and lymph nodes, as assessed by adoptive transfer of OX62+ VDCs labeled with 5 (and 6-)-carboxyfluorescein diacetate succinimidyl ester.