Fig. 6.

PRRSV nsp1 proteins inhibit expression from an ISRE promoter. HEK293T cells were cotransfected with pISRE-luc, pRL-SV40 and pCAGGS expressing nsp1 proteins or pCAGGS empty vector (P) for 20 h. Cells were then infected with Sendai virus (A) or treated with IFN-α (B) and IFN-β (C) for 20 h. The cells were harvested and measured for firefly and Renilla luciferase activities. Relative luciferase activity is defined as a ratio of firefly luciferase reporter activity to Renilla luciferase activity. Each data point shown represents a mean value from three experiments. Error bars show standard deviations of the normalized data.