FIG. 6.

HIV-1 R5 strain ADA induces apoptosis in MVECs in a dose-dependent manner. Representative TUNEL staining of HIV-1 ADA-treated MVECs is shown. Cells were infected with HIV-1 ADA for 72 h, after which cells were subjected to TUNEL staining. The amount of virus used ranged from 1 to 100 ng of HIV-1 p24 antigen equivalents per ml. As a positive control, MVECs were exposed to DNase at a concentration of 10 μg/ml for 10 min at room temperature. TUNEL assays were performed with the in situ cell death detection kit, TMR Red (Roche Diagnostics). The cells were analyzed by fluorescence microscopy (Olympus System microscope, model BX60, with fluorescence attachment BX-FLA). These results are representative of those from experiments performed in triplicate and repeated at least twice.