Figure 2.

Sting and cGas are required for the induction of IFN-β during ectromelia virus (ECTV) infection in L929 cells. (A) Western blot analysis of overexpressed cGas, Sting, and β-actin protein levels in L929 cells. (B) L929 (2 × 10⁵) cells were seeded in a 12-well plate and then were transfected with cGas, Sting-wt (S-wt), Sting-gt (S-gt), or empty (Vec.) plasmids. Thirty hours after transfection, cells were infected with ECTV (MOI of 5) for 18 h, and then the mRNA levels of IFN-α, IFN-β, and Ifit1 were analyzed by qPCR. (C) Western blot analysis of siRNA knockdown of cGas, Sting, and β-actin protein levels in L929 cells. (D) L929 (2 × 10⁵) cells were seeded in a 12-well plate and then were transfected with siRNAs for cGas (si-C1 and si-C2), Sting (si-S), or si-NC (si-N). Thirty-six hours after transfection, cells were infected with ECTV (MOI of 5) for 18 h, and then the mRNA levels of IFN-α, IFN-β, and Ifit1 were analyzed by qPCR. All the data represent mean ± SD of biological triplicates from at least three independent experiments. Statistical analyses were performed by one-way analysis of variance followed by the Duncan’s multiple range test. Con. means control group, which cells were only infected with ECTV (MOI of 5). In this figure, *P ≤ 0.05 and **P ≤ 0.01.