A non-invasive method to sample immune cells in the lower female genital tract using menstrual discs

Abstract

T cells in the female genital tract (FGT) are a key mediator of susceptibility to and protection from infection, including HIV and other sexually transmitted infections. There is a critical need for increased understanding of the distribution and activation of T cell populations in the FGT, but current sampling methods are invasive and expensive, limiting the ability to study these populations longitudinally. To address these challenges, we have developed a novel method to sample immune cells from the FGT utilizing disposable menstrual discs which are non-invasive, self-applied, and low-cost. To demonstrate reproducibility, we sampled the cervicovaginal fluid (CVF) of healthy, reproductive-aged individuals using menstrual discs over three sequential days. CVF was processed for cervicovaginal cells, and high parameter flow cytometry was used to characterize immune populations. We identified large numbers of live, CD45+ leukocytes, as well as populations of T cells and B cells. Within the T cell compartment, phenotypic features of T cell subsets were consistent with previous FGT studies utilizing more invasive approaches, including identification of both tissue resident and migratory populations. In addition, the T cell population structure was highly reproducible across days within individuals but divergent across individuals. Our novel approach to sampling immune cells in the FGT will decrease barriers to participation and empower longitudinal sampling in future research studies.