Figure 7

TNF-α drives the HIV-1 replication in unstimulated CD4⁺T lymphocytes treated with exosomes from F12/Hut-78 cells. A. Neutralization of soluble TNF-α. 10⁵ unstimulated CD4⁺ T lymphocytes were challenged with 60 μU of exosomes from either Hut-78 or F12/Hut-78 cells, and then infected with HIV-1. After washings, the cells were cultured in the presence of anti-TNF-α neutralizing antibodies or with unrelated IgGs. As control, unstimulated CD4⁺ T lymphocytes were treated with the indicated doses of recombinant TNF-α, infected by HIV-1, and then cultured in the presence of anti-TNF-α neutralizing antibodies or IgGs. Three days after challenges, the cells were analyzed for HIV-1 expression by FACS analysis. The fold increases of the percentages of HIV-1 CAp24-positive cells compared to cultures treated with HIV-1 alone are presented. Shown are the mean of fold increases + SD as calculated from three independent experiments with duplicates. *p < 0.05. B. Effects of the block of TNFR1 and TNFR2. The same procedure described for panel A was applied, except than unstimulated lymphocytes were incubated with neutralizing anti-TNFR1 or -TNFR2 antibodies either alone or in combination, or irrelevant isotype IgGs for 1 hour at 4°C before exosome and HIV-1 challenges. Three days later, the cells were analyzed for HIV-1 expression by FACS analysis. The fold increases of the percentages of HIV-1 CAp24-positive cells compared to lymphocytes treated with HIV-1 alone are presented. Shown are the mean of fold increases as calculated from two independent experiments with duplicates.