Figure 7.

Tlr9 and Sting are critical for resistance to ectromelia virus (ECTV) at a low infection dose. Sting^gt/gt, cGas^−/−, Tlr9^−/−, and wild-type (WT) mice (B6) were infected with 3 × 10³ plaque-forming units (PFUs) of ECTV in the left footpad. (A) Mice were monitored twice daily over 30 days for survival. (B) The expression of IFN-β in the spleens of the indicated mice at 3 days post-infection (dpi) was examined by qPCR. (C) Liver sections of the indicated mice at 7 dpi were stained with hematoxylin and eosin. (D–G) The spleen and liver from infected mice were harvested at 7 dpi, and then the viral genome copy numbers (D,E) and viral loads (F,G) were determined by qPCR and plaque assay, respectively. Statistical analyses were performed by one-way analysis of variance followed by the Duncan’s multiple range test. For survival experiments, we used the log-rank (Mantel–Cox). In this figure, ns, not significant; *P ≤ 0.05; **P ≤ 0.01; and ***P ≤ 0.001.