NS1-C inhibits IFN-β promoter activity induced by RIG-I. HEK-293TN cells were transiently transfected with IFN-β luciferase reporter plasmid, RIG-I and β-galactosidase expression plasmids, and vectors encoding NS1 from C/JJ/50 or C/JHB/1/66, or empty pCI vector. 24 h post transfection, cells were stimulated with poly(I:C) or vRNA, and eight hours post induction, luciferase activity of cell lysates was measured and normalised to β-galactosidase activity. Data shown are representative for three experiments with transfections performed in duplicates. Error bars indicate standard deviations. The zero control without ectopic RIG-I expression is depicted at the left.