An Epigenetic Compound Library Screen Identifies BET Inhibitors That Promote HSV-1 and -2 Replication by Bridging P-TEFb to Viral Gene Promoters through BRD4
Fig 2
Bromodomain inhibition promotes HSV-1 and HSV-2 infection.
(A) Effect of BD1 and BD2 inhibition on HSV-1 infection. Vero cells were treated with BD1 inhibitor JQ1 (300 nM), BD2 inhibitor RVX-208 (RVX, 500 nM), or HDAC inhibitor TSA (150 nM). (-)JQ1, an inactive enantiomer of JQ1, at 300 nM was also included as a control. The cells were infected with HSV-1 or HSV-2 (1 MOI) at 2 hr post treatment. The cells were harvested at 24 hr PI and used for plaque assay. The data are presented as mean ± SEM of triplicate samples. (B and C) Dose effect of JQ1 on HSV infection. Vero cells were treated with JQ1 at concentrations as indicated. HSV-1 or HSV-2 at 1 MOI were used. The samples were harvested at 24 hr PI for virus titration by plaque assay (B) or used for protein expression analysis by western blot (C). The bar graph represents quantitative measurement of viral protein expression (relative to infected but untreated controls). The experiment was performed independently 3 times. Data are presented as mean ± SEM of two independent measurements. (D) Time effect of JQ1 addition on HSV infection. HeLa cells were treated with JQ1 at 300 nM at time points as indicated. The time of inoculation was counted as 0, and -2 hr refers to 2 hr prior to infection. In parallel experiments, the virus was incubated with 300 nM JQ1 at RT for 1 hr and then used to infect the cells after dilution (Tx-V). The cells were infected with HSV-1 at 0.5 MOI for 36 hr and virus production was determined by plaque assay. (E) JQ1 accelerates HSV-1 infection. HeLa cells were mock-treated or treated with 300 nM JQ1 prior to HSV-1 infection (MOI = 0.3). The samples were harvested at times as indicated and virus production was titrated.