HIV-1 Tat cooperates with HSV-2 to induce KSHV lytic cycle replication.

<p>(<b>A</b>). <b>Effect of Tat on ORF26 mRNA expression in HSV-2-infected BCBL-1 cells.</b> Real-time quantitative PCR was performed to detect KSHV ORF26 mRNA expression in Mock-treated and pcDNA3.1-transfected BCBL-1 cells (<b>Mock+pcDNA</b>), Mock-treated and pTat-transfected BCBL-1 cells (<b>Mock+Tat</b>), or HSV-2-infected and pcDNA3.1-transfected BCBL-1 cells (<b>HSV-2+pcDNA</b>), HSV-2-infected and pTat-transfected BCBL-1 cells (<b>HSV-2+Tat</b>) for 6, 24, 48 and 72 hours. The results shown were from three independent experiments performed in triplicate. ** <i>p</i><0.01 for Student's t-test versus HSV-2+pcDNA group. (<b>B</b>). <b>Effect of Tat on vIL-6 protein expression in HSV-2-infected BCBL-1 cells.</b> Cell lysates were collected from HSV-2-infected and pcDNA3.1-transfected BCBL-1 cells, or HSV-2-infected and pTat-transfected BCBL-1 cells for 48 and 72 hours. Whole cell lysate were subjected to Western blot with the indicated antibody. (<b>C</b>). <b>Effect of Tat on Rta promoter activities in HSV-2-infected BCBL-1 cells.</b> BCBL-1, B95-8 and Vero cells were infected with Mock and then co-transfected with pcDNA3.1, p50-Luc and Renilla vector pRL-TK (<b>Mock+pcDNA3.1</b>), infected with HSV-2 and then co-transfected with pcDNA3.1, p50-Luc and Renilla vector pRL-TK (<b>HSV-2+pcDNA3.1</b>), or infected with HSV-2 and then co-transfected with pTat, p50-Luc and Renilla vector pRL-TK (<b>HSV-2+Tat</b>). Luciferase activities were measured, normalized to Rellina inner control, and presented as fold increase (<i>n</i>-fold). All data points were the averages of three independent experiments performed in triplicate. * <i>p</i><0.05 and ** <i>p</i><0.01 for Student's t-test versus HSV-2+pcDNA3.1 group, respectively. (<b>D</b>). <b>Effect of Tat on HSV-2 replication in BCBL-1 cells.</b> BCBL-1 cells were infected with Mock and then transfected with pcDNA3.1 (<b>Mock+pcDNA</b>), infected with HSV-2 and then transfected with pcDNA3.1 (<b>HSV-2+pcDNA</b>), or infected with HSV-2 and then transfected with pTat (<b>HSV-2+pTat</b>) for 24, 48 and 72 hours. Whole cell lysate were subjected to Western blot with the indicated antibody.