Figure 5.

Real-time PCR and caspase 3 activity of CHIKV-challenged transformed Vero cell clones. (A) Viral RNA was obtained from 3 dpi cell culture supernatants challenged at an MOI of 0.005. Quantification was performed using a primer specific to the nsP2 region of the CHIKV (Materials and Methods). (B) Supernatants collected from 3 dpi cell cultures challenged at an MOI of 0.005 were used to infect untransformed Vero cells, and caspase 3 activity was measured at 2 dpi using a standard luciferase activity (Materials and Methods). Uninfected cell controls (ctrl) were also used to screen for background caspase 3 activity. Statistically significant differences (Dunnett’s, p < 0.01) relative to the infected control sample (wt) were determined using one-way ANOVA (GraphPad prism 6.0 software).