FIG 2 .

JCPyV establishes a low-level persistent infection in HRPTE cells. HRPTE cells were infected with JCPyV or BKPyV, and expression of VP1 was assessed every 3 days for 21 days by flow cytometry. Results are expressed as percentages of VP1-positive cells calculated using FlowJo (A). SVGA cells were infected with JCPyV and stained as previously stated (inset). Supernatants from infected HRPTE cells were collected at 18 dpi and 12 dpi for JCPyV and BKPyV, respectively, and used to infect newly plated HRPTE cells. Cells were fixed and stained for VP1 at 3 dpi, and positive nuclei were counted using fluorescence microscopy at ×10 magnification (B). The total number of cells per visual field was determined using DAPI nuclear staining, and the percentage of VP1-positive cells is reported on top of each bar in panel B. Results represent the average from three independent experiments, and error bars represent standard deviations (SD). In panel A, a total of 30,000 events were recorded per time point.