Increased frequency of Foxp3 + CD8 + T cells is associated with disease progression during HIV infection

Recent years have witnessed unprecedented strides in comprehending non-CD4 regulatory T cells (Tregs), such as CD8 + Tregs and double-negative T cells (DNT cells), and their role in sustaining immune tolerance and restricting immune activation. This study investigates the role of Foxp3 + CD8 + T cells during HIV infection and assess the markers associated with CD4 + Tregs.

This study was designed as a cross-sectional cohort study, comprising 21 age-matched healthy controls, 122 treatment-naive participants, and 60 people with HIV (PWH) receiving successful treatment (antiretroviral therapies, ARTs).

The frequency of Foxp3 + CD8 + T cells was assessed alongside CD4 + Treg-associated markers and plasma inflammatory factor levels.

Foxp3 + CD8 + T cells were enriched in PWH with CD4 + T cell count less than 350 cells/microl and persisted after ART. Moreover, the Foxp3 + CD8 + T cells were correlated with CD4 + T cell count, CD4/CD8 ratio, and the parameters of activation and systematic inflammation in PWH. Moreover, Foxp3 + CD8 + T cells expressed different levels of Tregs related markers compared to CD4 + Tregs and Foxp3 + DNT cells.

The Foxp3 + CD8 + T cells are associated with HIV disease progression and employ distinct mechanisms to exert their functions.