FIG. 3.

Rosco minimally affects basal expression of β-gal from the ICP6 Promoter. (A) Experimental design. Vero cells were pretreated with CHX (75 μg/ml) for 1 h (t = −1). At 0.5 h after CHX pretreatment was initiated (t = −0.5), one set of cultures was pretreated or not with Rosco (100 μM). Cells were then infected with 5 PFU of KOS6β per cell at t = 0 and incubated in the presence or absence of 100 μM Rosco for 12 h in medium containing CHX (t = 12 hpi). Infected cells were either harvested or released into medium containing the RNA synthesis inhibitor, ActD (1 μg/ml), for an additional 12 h (t = 24 hpi). At the end of the second 12-h treatment period, extracts were prepared and β-gal assays performed. (B) Histogram showing results of a typical β-gal assay. All samples are compared to KOS6β-infected cells harvested after the initial 12-h CHX block (far left sample), which was given the arbitrary value of “1.” The data shown represent the means of duplicate samples; bars indicate the standard deviations of the means. Cell viability was maintained in these cultures 24 hpi. Specifically, all KOS6β-infected cells were 93% viable compared to mock-infected, untreated samples in which 96% of the cells were viable, as determined by trypan blue exclusion.