Fig 4.

Role of epigenetic mechanisms in the effect of PARP-1 on retroviral infection. DT40 WT, KO, and h-1 cells were infected with TRIPluc and MLVluc, and 4 days later, the cells were treated or not (control) with sodium butyrate for 24 h (a and b) or with 5-azacytidine for 36 h (c and d), and infectivity (luciferase levels) and cell viability (ATP levels) were measured. Luciferase activity was normalized to ATP levels in all of the experiments. (a and c) ATP-normalized luciferase activity is expressed relative to the values found in the corresponding infected cell lines that were not treated. (b and d) ATP-normalized luciferase activity (infectivity) expressed relative to the infectivity values detected in the WT cells in the treatment or control group. The standard deviation values represent triplicate measurements from one infection experiment. The data are representative of three independent experiments.