Figure 3. XAF1^MKO mice exhibit resistance to viral infection.

WT and XAF1^MKO mice (6–8 weeks) were i.n. infected with a sublethal dose (0.1 hyaluronic acid [HA]) of PR8.

• A, B
  Survival rate (A) and body weight loss (B) were monitored for 8 days (n = 10).
• C
  Viral titers in the lung and trachea were quantified by TCID₅₀ assay on day 2 (n = 5).
• D
  ELISA of IFN‐I levels in the sera of WT and XAF1^MKO mice infected with H1N1 strain PR8 on day 2 (n = 3).
• E
  H&E‐stained lung tissue sections 2 days after infection. Inflammation scores are presented in a bar graph (n = 4). Scale bar, 200 μm.
• F–H
  Survival rate (F, n = 12) and viral titer (G, n = 4) in the spleen and IFN‐β in the serum (H, n = 4) of WT and XAF1^MKO mice intravenously injected with HSV‐1 (3 × 10⁶ PFU per mouse).
• I–K
  WT and XAF1^MKO mice crossed with IFNAR^−/− mice were i.n. infected with a sublethal dose (0.1 HA) of PR8. The survival rate (I, n = 10), viral titer in the lung (J, n = 4), and serum IFN‐β level (K, n = 4) were monitored for the indicated times.

Data information: All data are representative of at least three biologically independent experiments. The data are presented as the means ± SDs. The significance of differences was determined by t‐tests. *P < 0.05, **P < 0.01, and ***P < 0.005.