Figure EV3. Improved immune protection in T‐bet‐deficient mice following influenza virus infection and bacterial superinfection with Streptococcus pneumoniae serotype S3, related to Figs 3, 4B and 5B.

• A
  Wild‐type mice were infected with indicated doses of S. pneumoniae serotype 19F or S3 bacteria alone and assessed for survival.
• B–F
  Wild‐type and T‐bet^−/− mice were infected with sub‐lethal dose of influenza virus followed by sub‐lethal dose of secondary bacterial challenge (S. pneumoniae serotype S3, 50 cfu) 7 days later. (B) Survival of mice following post‐influenza bacterial infection. (C) Pneumococcal cfu in lung homogenates of mice infected with 50 cfu of S. pneumoniae serotype S3 alone or following influenza virus infection. (D) Absolute immune cell counts in lungs, as assessed by flow cytometry. (E) Concentrations of IL‐17 and IL‐22 in lung homogenates of mice, assessed by ELISA. (F) T‐bet^−/− mice were administered αIL‐17 or IgG isotype control antibody every other day from day −2 post‐secondary bacterial infection and monitored for survival.

Data information: Data in (A–C) and (F) are combined from two independent experiments with 6–16 mice per group. Data in (D) and (E) are representative of two independent experiments with four mice per group. All data are represented as mean ± SEM. Statistical significance was determined by log‐rank test in (B) and (F), Mann–Whitney U‐test in (C) and unpaired Student's t‐test in (D) and (E).