Figure 1

Exosome-dependent HIV-1 replication in unstimulated CD4⁺T lymphocytes after co-cultivation with Hut-78/F12 cells. A. HIV-1 replicates in unstimulated CD4⁺ T lymphocytes co-cultured in trans-well plates with F12/Hut-78 cells. F12/Hut-78 cells or parental Hut-78 cells were put in the upper chamber of trans-well plates where unstimulated CD4⁺ T lymphocytes were seeded in the bottom chamber. After overnight co-culture, unstimulated CD4⁺ T lymphocytes were recovered and infected by a T-tropic HIV-1 strain in the presence or not of AZT. As control, unstimulated and PHA-treated CD4⁺ T lymphocytes were infected by HIV-1 or left untreated (Mock). Three days later, the lymphocyte cultures were analyzed by FACS for the expression of HIV-1 Gag-related products. In the upper displays, shown are the dot-plots of FACS analysis from a representative experiment. Percentages of HIV-1 Gag positive cells are indicated in each plot. In the bottom, the fold increases of the percentages of HIV-1 CAp24-positive cells compared to cells 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 inhibitors of exosome release on the HIV-1 susceptibility of unstimulated CD4⁺ T lymphocytes co-cultured with F12/Hut-78 cells. Trans-well co-cultures were run as described for panel A, however in the presence or not of the inhibitors of exosome release GW4869 and Spiroepoxide. After overnight co-culture, the unstimulated CD4⁺ T lymphocyte cultures and, as control, PHA-activated lymphocytes treated or not with the inhibitors of exosome release were washed and infected by HIV-1. Three days later, the cell cultures were analyzed by FACS for the expression of HIV-1 Gag-related products. 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.