FIG. 7.

An HIV-1 R5 strain with a deletion in the Nef gene (ADAΔNef) induces apoptosis in MVECs at lower levels than wild-type HIV-1 ADA. Representative TUNEL staining of HIV-1 ADAΔNef-treated MVECs is shown. Cells were infected with HIV-1 ADAΔNef for 72 h, after which they were subjected to TUNEL staining. The amount of virus used ranged from 1 to 100 ng of HIV-1 Gag p24 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 with 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.