Contribution of CD4+, CD8+CD28+, and CD8+CD28- T cells to CD3+ lymphocyte homeostasis during the natural course of HIV-1 infection

The relationship between the number of circulating CD4(+) T cells and the presence of particular CD8(+) T cell subsets was analyzed by flow cytometry on PBL from asymptomatic HIV-l-infected patients whose specimens were collected every 2 mo for a total period of 32 mo, Only slight variations were detected in the absolute number of lymphocytes and percentage of CD3(+) lymphocytes, whereas both CD4(+) and CD8(+) T cell subsets showed wide intrapatient variation. Variations in the number of CD8(+)CD28(+) cells paralleled those of the CD4(+) T cell subset in each patient tested, while the presence of CD8(+)CD28(-) T cells correlated inversely with CD4(+) and CD8(+)CD28(+) T cells, These data show that changes in the number of circulating CD4(+)-and CD8(+)CD28(+)-T cells are strongly related to the presence of CD8(+)CD28(-) T cells in these patients. Insight into the significance of CD8(+)CD28(-) T cell expansion will allow us to understand the mechanisms and significance of the HIV-1-driven change in CD4(+)/CD8(+) T cell homeostasis and the basic immunopathology of HIV disease.