The Basic domain of Tat is involved in the cytoprotective effect of HIV-1 Tat. (A) Primary human macrophages were transduced with either HIV-GFP wt vector or HIV-GFP Tat 49/50 vector and treated with SNP 1mM for 24 hours. Cell death was then analyzed using a vital dye (red cells = dead). Transduced cells are shown in green (GFP+) while transduced/dead cells are shown in yellow (red+green merge; numbers reflect the % yellow cells in ~200 green cells). The average percentage of cell death and the standard deviation between three independent experiments in triplicate is shown. Luciferase assay results for fold activation of the HIV-1 LTR for the wildtype and the Tat basic domain mutant vectors are also shown. BF: bright field. (B) CHME5 sublines expressing wildtype or mutant HIV-1 Tat proteins were exposed to LPS/CHX for 24 hours and analyzed for viability using the trypan blue assay. Results are shown as percent cell death. (C) CHME5 sublines expressing wildtype or mutant Tat CHME5 sublines were lysed and analyzed for PTEN protein levels by Western blot. Normalized expression levels of PTEN (relative to α-tubulin) are shown.