Phenotype and Susceptibility to HIV-infection of CD4(+) Th17 Cells in the Human Female Reproductive Tract

Prevention of sexual acquisition of HIV in women requires a substantial increase in our knowledge about HIV-target cell availability and regulation in the female reproductive tract (FRT). In this study, we analyzed the phenotype and susceptibility to HIV-infection of CD4(+) T cell in the endometrium (EM), endocervix (END) and ectocervix (ECT) of the FRT. We found that Th17 cells represent a major subset in FRT tissues analyzed, and that Th17 cells were the main CD4(+) T cell population expressing CCR5 and CD90. In pre-menopausal women, CD4(+) T cells and Th17 cells in particular, were significantly lower in EM relative to END and ECT. Th17 cells were elevated in EM from post-menopausal women relative to pre-menopausal tissues, but not changed in END and ECT. Susceptibility of CD4(+) T cells to HIV infection measured as intracellular p24 was lowest in the EM and highest in ECT. Additionally, we found that Th17 cells co-expressing CCR5 and CD90 were the most susceptible to HIV-infection. Our results provide valuable information for designing preventive strategies directed at targeting highly susceptible target cells in the FRT.