The NS3 protease inhibitor BILN2061 restores MAVS/IPS-1-mediated, but not dsRNA-mediated, IFN-β induction in cells infected with HCV. (A) NS3 protease inhibitor restores the MAVS/IPS-1-mediated IFN-β induction. Twenty-four hours before cotransfection with the MAVS/IPS-1 expression vector and the IFN-β promoter reporter plasmid, the NS3 protease inhibitor BILN2061 was added to mock infected and JFH-1 infected cells at a final concentration of 10 μM. Luciferase activities were analyzed 36 h after transfection in the absence of poly(IC). (B) NS3 protease inhibitor fails to restore the dsRNA-mediated IFN-β induction. Similar to A, cells were pretreated with the protease inhibitor BILN2061 before plasmid transfection. Cells were further transfected with or without poly(IC) 36 h after transfection of the IFN-β promoter reporter plasmid. Sixteen hours later, luciferase activities were analyzed, and the results are expressed as fold induction.