OUP accepted manuscript

Background

Mucosa-associated invariant T (MAIT) cells are innate-like T cells with specialized antimicrobial functions. Circulating MAIT cells are depleted in chronic human immunodeficiency virus (HIV) infection, but studies examining this effect in peripheral tissues, such as the female genital tract, are lacking.

Methods

Flow cytometry was used to investigate circulating MAIT cells in a cohort of HIV-seropositive (HIV⁺) and HIV-seronegative (HIV⁻) female sex workers (FSWs), and HIV⁻ lower-risk women (LRW). In situ staining and quantitative polymerase chain reaction were performed to explore the phenotype of MAIT cells residing in paired cervicovaginal tissue. The cervicovaginal microbiome was assessed by means of 16S ribosomal RNA gene sequencing.

Results

MAIT cells in the HIV⁺ FSW group were low in frequency in the circulation but preserved in the ectocervix. MAIT cell T-cell receptor gene segment usage differed between the HIV⁺ and HIV⁻ FSW groups. The TRAV1-2–TRAJ20 transcript was the most highly expressed MAIT TRAJ gene detected in the ectocervix in the HIV⁺ FSW group. MAIT TRAVJ usage was not associated with specific genera in the vaginal microbiome.

Conclusions

MAIT cells residing in the ectocervix are numerically preserved irrespective of HIV infection status and displayed dominant expression of TRAV1-2–TRAJ20. These findings have implications for understanding the role of cervical MAIT cells in health and disease.