FIGURE 1.

Only some HDACis reactivate HIV in Jurkat cells. A. acetylation of histone H3 and tubulin does not correlate with HIV reactivation in JΔK cells. Cells were incubated with increasing concentrations of different HDACis or DMSO as indicated for 24 h (upper panel: SAHA from 0.5, 2 to 10 μm; MS-275 from 2, 5 to 25 μm; ST-80 from 2.5, 10 to 40 μm; TBSA from 1, 5 to 20 μm). The production of new viral particles was determined by measuring levels of p24 capsid ELISA in supernatants. Values are presented as -fold activation over the DMSO control, which was set to 1 (bar 1). Error bars represent S.E. of mean of experiments performed in triplicate. Western blotting for acetylated tubulin (lower panel, bar 1) and histone H3 (lower panel, bar 3) confirmed the specificity of HDAC inhibition. Amounts of total tubulin and histone H3 as loading controls are presented in lower panel, bars 2 and 4. B, JΔK cells were incubated with different HDACis (SAHA, 5 μm; MS-275, 12.5 μm; ST-80, 10 μm) or combinations thereof for 24 h. DMSO was included as the control. The production of new viral particles was determined by measuring p24 capsid levels in supernatants. Values are presented as -fold activation over the DMSO control. Error bars are as in A. C, the episomal HIV.Luc plasmid target recapitulates effects of HDACis on the integrated HIV genome in Jurkat cells. Jurkat cells were transfected with an HIV LTR plasmid target (HIV.Luc). 24 h later, cells were incubated with the indicated concentrations of HDACis (SAHA, 5 μm; MS-275, 25 μm; ST-80, 30 μm; TBSA, 20 μm) for an additional 24 h prior to luciferase enzymatic assays. The luciferase activity was determined in cell lysates and normalized to total protein. Values are presented as -fold activation over the DMSO control. Error bars are as in A.