Figure 5. IAV coinfection induces Tregs.

C57BL/6 mice were infected via aerosol with a low dose of Mtb H37Rv and 12 days later coinfected i.n. with 1 × 10⁴ PFU IAV (A/HH/05/09 H1N1). Lungs were collected at indicated time points and analyzed by flow cytometry for (A) presence of Foxp3⁺ CD4⁺ T cells, (B) IL-10–producing Foxp3⁺ CD4⁺ T cells and (C) the MFI of IL-10 produced by Foxp3⁺ CD4⁺ T cells (n = 3–5 per group [day 15 IAV n = 2], representative of 2 independent experiments). Each data point represents 1 mouse. *P ≤ 0.05; **P ≤ 0.01, ***P ≤ 0.001 determined by (A–C) 1-way ANOVA followed by Tukey’s multiple-comparison test.