STING and MAVS mediate RIG-I induction of interferon.

<p>EPC cells were transfected with 1 µg of pIFNproLUC reporter in combination with various plasmid constructs (1 µg each, except for dominant-negative mutants of MAVS and STING combinations where 0.5 µg of each plasmid was used) as mentioned under each histogram. An empty vector (pcDNA) was added in some experiments to keep the total amount of transfected DNA constant (3 µg total DNA for 5×10⁶ cells). In the condition were pRIG-I Nter-eGFP was not present in the transfection mixture, a peGFP vector was added. At 24 h and 48 h posttransfection, eGFP and luciferase signals were determined. Values of luciferase activities were normalized to the levels of eGFP fluorescence. The fold induction was calculated as the ratio of stimulated versus unstimulated (pcDNA alone) samples. Means of three independent experiments are shown together with the standard errors. Student’s <i>t</i>-test was used for statistical analysis, and asterisk indicate significant differences (*<i>p</i><0.05 and **<i>p</i><0.01).