Fig. 2.

CS-exposed mice exhibit a defective immune response to S. pneumoniae. (2 columns).

Mice were chronically exposed to air or CS over a period of 12 weeks and then intranasally challenged with 5 × 10⁴ CFU of S. pneumoniae (Sp) or with PBS (Mock). IL-17 and IL-22 levels were evaluated in BAL fluids (a), blood (b) and in the supernatants of restimulated pulmonary cells without (NS) or with anti-CD3 Ab (c). IL-17 and IL-22 producing cells were identified by intracellular staining among pulmonary NK cells (CD45⁺ TCRβ⁻ NK1.1⁺), NKT-like cells (CD45⁺ TCRβ⁺ NK1.1⁺), T cells (CD45⁺ TCRβ⁺ NK1.1⁻) and Lin-negative cells (CD45⁺ CD3⁻ CD11c⁻ CD11b⁻ CD45Rb⁻ NK1.1⁻ CD90.2⁺ CCR6⁺) cells (d and e). We have reported representative dot blot of the selected sub-populations and percentages of cytokine⁺ cells among the respective cell population are represented (c). The mean percentage of IL-17⁺ and IL-22⁺ cells was calculated for NK, NKT and Lin⁻ cells (d). Results are expressed as mean ± SEM (n = 48–80 mice per group). One representative experiment out of three independent ones is shown concerning intracellular staining. *: p < 0.05 vs controls (one-way ANOVA test).