Initiation of oral pre-exposure prophylaxis associated with changes in genital tract T cell phenotypes in women exposed to HIV

Oral tenofovir-based HIV-pre-exposure prophylaxis (PrEP), approved for use in preventing human immunodeficiency virus (HIV) infection, has been implicated in altering the immune landscape. We leveraged longitudinal samples from heterosexual couples with the male partner living with HIV and the female partner without HIV initiating PrEP after enrollment. Applying high parameter flow cytometry to cells from ectocervical and vaginal biopsies and peripheral blood samples, we found a decrease in activated ectocervical CD8+ and CD4+ T cell subsets after oral PrEP exposure. Our data expand the understanding of the immunological impact of oral PrEP and potential protective mechanisms of PrEP usage.