Fig. 6.

PR8_HA(D-MVEKT) but not PR8_HA(MVEKT) virus causes epithelial damage in Tmprss2^−/− mice. Female 8–12-week-old WT and Tmprss2^−/− KO mice were infected intranasally with 2×10⁵ f.f.u. PR8 (WT: n=3; KO: n=3), PR8_HA(HK) (WT: n=3; KO: n=3), PR8_HA(MVEKT) (WT: n=3; KO: n=3) or PR8_HA(D-MVEKT) (WT: n=3; KO: n=3). Lungs were prepared at day 4 p.i., sectioned and stained with H&E. Bronchiolar epithelial damage (a) and inflammation (b) were scored. WT mice: black, Tmprss2^−/− mice: red. Error bars represent ±1 sem. Statistical significance was determined by ANOVA and a post-hoc pair-wise t-test and Bonferroni correction for multiple testing. P-values of <0.05 were considered significant (***P<0.001). Inflammation scores were not significantly different by ANOVA. Therefore, no post-hoc analysis was performed.