Fig. 5.

Both MDA5 and RIG-I are required for the induction of antiviral cytokine production by mast cells in response to VSV infection. a siRNA was used to knock down endogenous PKR, MDA5, RIG-I and TLR3 as described in the Methods. The effects of siRNAs were confirmed by real-time PCR 24 h after transfection. b BMMCs were stimulated with VSV 24 h after the corresponding siRNA transfection. IFN-α, IFN-β, IL-6 and IL-10 levels were determined by ELISA 24 h after VSV infection. c IL-6 production upon stimulation with LPS or IgE cross-linking was measured by ELISA 6 h after stimulation. Means ± SD of 3 separate experiments. * p < 0.05, ** p < 0.01, *** p < 0.001, vs. control siRNA-treated cells.