Enhanced IFN-γ Production in Vitro by CD8+ T Cells in Hemophiliacs with AIDS as Demonstrated on the Single-Cell Level

We examined T cells from HIV-infected hemophiliacs under antiviral therapy, on the single-cell level, for cytokine production in vitro in response to stimulation. The percentage of IL-2-producing cells was markedly decreased among both CD3+CD8− and CD3+CD8+ cells, while the proportion of IFN-γ-producing cells was preserved among CD3+CD8− cells and increased among CD3+CD8+ cells in HIV+ subjects, compared with HIV-uninfected controls. The increase in IFN-γ-producing CD8+ cells was accounted for by the expansion of CD8+CD28− cells among total CD8+ T cells and by the higher percentage of IFN-γ-expressing cells among both CD8+CD28+ and CD8+CD28− cells in HIV+ individuals, compared with controls. The enhanced IFN-γ production in CD8+ cells from individuals in the advanced phase of HIV infection might implicate the hostʹs response to chronic viral infection or senescence of host CD8+ cells.