Immunophenotypic patterns of CD8⁺ T cell subsets expressing CD8αα and IL-7Rα in viremic, aviremic and slow progressor HIV-1-infected subjects

Evidence from animal models suggests that the expression of CD8αα homodimer on CD8⁺ T cells plays a key role in the generation of long-lived memory cells. Here, we studied the quantitative alterations of CD8⁺ T cell subsets expressing CD8αα, interleukin-7 receptor (IL-7Rα) and activation markers in HIV-1-infected individuals including aviremic, viremic and slow progressor subjects using eight-color flow cytometry. Compared to slow progressor subjects, expression of CD8αα was significantly reduced in aviremic and viremic patients and this reduction occurred mainly within central memory cell subsets and not in naive and effector memory compartments. Persistence of antigenemia leads to IL-7Rα loss mainly on central and pre-terminal memory CD8⁺ T cell subsets in viremic patients but not in slow progressor subjects. Compared to aviremic and viremic patients, slow progressor subjects had lower levels of IL-7 and reduced activated cells. The expression of CD8αα was not significantly related to IL-7Rα although negative associations were evidenced within all CD8⁺ T cell subsets. Collectively, these results further advance the characterization of immunophenotypic patterns of CD8⁺ T cell subsets expressing CD8αα/IL-7Rα and provide new insights into the ability of HIV-1 infection to alter memory cell population.