Figure 4.

TLR3 expression was induced by IFN-α via IFNAR1, whereas FC-99 inhibited the poly(I:C)-induced IFN-α via IRF3. RAW264.7 cells were treated with 25 μg·mL⁻¹ poly(I:C) for the indicated time periods, mRNA levels of IFN-α (A) and TLR3 (B) were measured by Q-PCR (n = 4). *P < 0.05, **P < 0.01, ***P < 0.001 versus control. (C) RAW264.7 cells were transfected with control siRNA (si-NC) or siRNA targeting IFNAR1 (siIFNAR1) for a total of 48 h and IFNAR1 mRNA levels were determined by Q-PCR (n = 4). (D) After transfected for 48 h, cells were treated with 25 μg·mL⁻¹ poly(I:C) for 6 h and TLR3 mRNA were measured by Q-PCR (n = 4). RAW264.7 were pretreated with FC-99 for 2 h before 25 μg·mL⁻¹ poly(I:C) stimulation for the indicated time periods. (E) IFN-α mRNA levels were tested by Q-PCR (n = 4). (F) Protein levels of phospho-IRF3, IRF3 and GAPDH were tested by Western blot. Histogram showed the relative band intensity from three independent experiments. The data are means ± SEM. **P < 0.01, ***P < 0.001.