Figure 3. JCV_CPN transfected IMR-32, SVG and Cos-7 cells produce low levels of infectious virions.

Supernatant from transfected Cos-7, SVG and IMR-32 cells was collected 7, 14 and 21 days post-transfection, and used to infect naive Cos-7 cells. At 7 days post-infection, cells were collected and either analyzed for JCV DNA using QPCR (A, C and D) or stained for VP1 and analyzed using flow cytometry (B). Supernatant collected 7 days post-transfection from JCV_CPN transfected Cos-7 (A), SVG (C) or IMR-32 (D) cells can establish an infection in naïve Cos-7 cells, as measured by the presence of JCV DNA 7 days post-infection. Levels of DNA detected with JCV_CPN infection are significantly lower than with JCV_Mad-1 infection (A, C and D). (B) VP1 positive cells are detected after infection with JCV_Mad-1, but not JCV_CPN containing supernatant. Data is the average of 3–4 independent experiments. Error bars represent standard deviation. P vales were calculated using Wilcoxon rank test for QPCR data, comparing JCV_CPN to JCV_Mad-1. P-values for flow cytometry data were calculated using students t test, comparing JCV_Mad-1 and JCV_CPN to mock at each time point. ND is not detected.