Infected cell viability and Tat-induced HIV-1 LTR transcription are inhibited by alsterpaullone. A) HIV-1 infected cells (ACH2, OM10.1, and U1) and corresponding control uninfected cells (CEM, Jurkat and U937) were plated in 24-well plates and cultured with increasing concentrations of alsterpaullone (0.01-5 μM). After 48 hours, the cells were stained by trypan blue and percent viability calculated with a hemocytometer. Assays were performed in triplicate, average values and standard deviations are shown. B) MTT assays were used for HIV-1 infected and corresponding control uninfected cells. Cells were seeded in a 96-well plate and cultured with 0.25 μM alsterpaullone, and 48 hours later, absorbance was read at 570 nm. Percent viability assays were performed in triplicate and average values and standard deviations are shown. C) TZM-bl cells were transfected with 1 μg of Tat and treated the next day with DMSO or the indicated compound (50, 150, or 300 nM). Cells were processed 48 hours post drug treatment for luciferase assays. Assays were performed in triplicate, average values and standard deviations are shown.