IRF-1 is dispensable for type I IFN response in VSV infections.

Mice were infected intranasally with 5×10⁶ pfu of VSV. A, IRF-1^+/−Mx2Luc and IRF-1^−/−Mx2Luc transgenic mice were subjected to whole body imaging. Mice were imaged before treatment (0 h) and over time as indicated. Images from a representative mouse are shown. The rainbow scale indicates the number of photons measured per second per cm² per steradian (sr). B, Serum was collected from WT and IRF-1^−/− mice at different time points post infection. IFN-α protein level was determined by ELISA. Data represents mean with SEM of 5–6 mice in each group per time point. Asterisks indicate statistical significance calculated by Mann-Whitney test, ** p<0.005