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 CD8 alpha alpha homodimer on CD8(+) T cells plays a key rote in the generation of long-lived memory cells. Here, we studied the quantitative alterations of CD8(+) T cell subsets expressing CD8 alpha alpha, interleukin-7 receptor (IL-7R alpha) 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 CD8 alpha alpha 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-7R alpha 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 tower levels of IL-7 and reduced activated cells. The expression of CD8 alpha alpha was not significantly related to IL-7R alpha although negative associations were evidenced within at CD8(+) T cell subsets. Collectively, these results further advance the characterization of immunophenotypic patterns of CD8(+) T cell subsets expressing CD8 alpha alpha/IL-7R alpha and provide new insights into the ability of HIV-1 infection to alter memory cell population. (c) 2007 Elsevier Inc. All rights reserved.