Figure 4.

IRF1 deficiency increased the severity of Pseudomonas keratitis at 3 dpi and attenuated flagellin-induced protection in B6 mice. WT or IRF1^−/− B6 mice were topically pretreated with 500 ng flagellin or PBS for 24 hours, and then infected with ATCC 19660 at 10⁴ CFU for 3 days. Keratitis progression was photographed (A), and clinical scores were assigned at 1, 2, and 3 dpi (B). The whole cornea was then collected for viable bacterial count (C), MPO activity assay (D), and CXCL2 ELISA (E). P values were generated using unpaired Student's t-test (*P < 0.05; **P < 0.01). The figure is a representative of three independent experiments.