FIG 4.

US28 is important for a successful latent infection in Kasumi-3 cells. (A) Kasumi-3 cells were infected with each of the indicated viruses. For each infected cell population, extracellular DNA was collected over a 5-day time course and quantified by qPCR using primers directed at UL123. Each sample was analyzed in triplicate. *, P < 0.001 relative to the WT value at 5 days p.i. (B) Parallel cultures from the experiment shown in panel A were treated with TPA to induce lytic transcription for an additional 2 days. Extracellular viral genomes were quantified as described for panel A. *, P < 0.001. (C) To confirm that the extracellular virions produced in the experiment shown in panel A were infectious, the infected Kasumi-3 cell subsets were each cocultured with naive fibroblasts for 7 days. Viral plaques (mCherry-positive) were visualized by fluorescence microscopy.