<i>Ifi35</i> expression contributes to increased morbidity following avian H5N1 and human H1N1 influenza infection.

<p><b>(A)</b> C57Bl/6N (WT; black) or <i>Ifi35</i>^-/- (red) mice were intranasally infected with 10⁴ TCID₅₀ of highly pathogenic H5N1 (A/Hong Kong/213/2003), or <b>(B)</b> 100 EID₅₀ of H5N1-Vietnam/PR8 (H5N1-VN/PR8; described in Materials and Methods), or <b>(C)</b> 10⁴ TCID₅₀ of pandemic H1N1 A/California/04/2009 and monitored for weight loss. <b>(D)</b> Littermate <i>Ifi35</i>^+/+ (black), <i>Ifi35</i>^+/- (grey), or <i>Ifi35</i>^-/- (red) mice were infected with 100 EID₅₀ of H5N1-VN/PR8 and monitored for weight loss. Starting weight is indicated with a dashed line at 100%. Values are the means of at least three independent experiments ± SEM. n = 18–29 per group <b>(E)</b> Viral titer (log₁₀ TCID₅₀/mL) in bronchoalveolar lavage fluid from WT (black circle) or <i>Ifi35</i>^<i>-/-</i> (red circle) mice at the indicated time-points post infection. n = 8–14 mice for each time-point from at least three independent experiments. Each symbol represents an individual mouse. Bars represent the mean from at least three different experiments (± SEM). Assay limit of detection (LOD) indicated at 1x10² TCID₅₀/mL; dotted line. *<i>P</i> < 0.05, **<i>P</i> < 0.001, ***<i>P</i> < 0.0001 using multiple student t-test for <b>(A-C)</b> and <b>(E)</b>, One-way ANOVA multiple-comparison for <b>(D)</b>.