HIV-specific CD8+T-cell apoptosis is blocked by a p38 inhibitor. (Ai) CD14 macrophages and CD8 T cells were isolated from HIV-1-negative PBMC donors as described in “Materials and methods.” (Aii) Macrophages were infected with HIV-1 wild-type pseudovirus (NL4-3 virus that complemented with VSV-G envelope) (100 TCID50/1 × 106 cells per milliliter) and incubated with latex beads before being mixed with autologous CD8 T cells. Fourteen hours after CD8 T cells were added to infected macrophages, cells were harvested and stained with CD8-FITC/annexin-V-PE. Note that the CD8 T cells were induced to undergo apoptosis. (B) Autologous macrophages were uninfected or infected with pseudovirus HIV-1 NL4-3 ΔNef virus or infected with NL4-3 Wt virus (viruses that complemented with VSV-G envelope) at concentration of 100 TCID50/1 × 106 cells/mL, were stimulated with latex beads, and were incubated with purified mock CD8+ T cells in the presence or absence of neutralizing anti-FasL antibody or with 1 μM p38 inhibitor overnight. Cells were then harvested and stained for CD8 plus annexin-V. Apoptosis analysis was performed by gating the low forward and CD8 scatter of cells. The percentage values represent the gated CD8 annexin V-positive cells. A representative experiment of 3 performed is shown.
