FIG. 4.

T170E mutation abolishes RIG-I antiviral activity. (A) VSV-EGFP replication in complemented RIG-I^−/− MEF. RIG-I WT, RIG-I T170A, or RIG-I T170E was stably expressed in RIG-I^−/− MEF, and these cells were infected with VSV-EGFP at an MOI of 0.5. Twenty-six hours after infection, virus replication and titers were determined by GFP expression (left) and plaque assay (right), respectively. (B) IFN-β production in complemented RIG-I^−/− MEF. RIG-I^−/− MEF stably expressing RIG-I WT or the indicated RIG-I mutants were infected with 50 HA units/ml SeV or with ΔNS1 A/PR8/34 influenza virus at an MOI of 2. Twenty-four hours after infection, IFN-β production in the supernatants was determined by ELISA. Statistical analysis was performed by unpaired Student's t test.