Fig. 4.

IFNa expression in TO cells in response to overexpression of VP1 in combination with IRF1 or IRF3. Cells were transfected with expression constructs for VP1, IRF1 and IRF3 in combination with plasmid control or VP1 in combination with IRF1 or IRF3. Cells transfected with IPS-1 or preVP2 were used as positive and negative control. RNA was extracted after 24 h and IFNa expression was determined by qPCR relative to transcript levels in plasmid control transfected cells (=1). Gene expression was normalized against 18S rRNA. Values are mean ± SD (N = 3). Asterisks denote significant differences from vector control (p < 0.05). Cells transfected with VP1 + IRF1 were significantly different from cells transfected with IRF1 + vector control and from VP1 + vector control (p < 0.005). Cells transfected with VP1 + IRF3 were significantly different from cells transfected with IRF3 + vector control and from VP1 + vector control (p < 0.005).