Fig. 3.

CS-exposed mice exhibited a defective response of pulmonary APC to S. pneumoniae. (1.5 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-1b and Il-23 mRNA levels were measured in lung tissues 24 h post-infection (a). CD45⁺ Siglec F⁺ AM and CD11c⁺ Ia⁺ CD64⁺ DC were sorted by flow cytometry 24 h post-infection. IL-1β and IL-23 levels were evaluated by ELISA in supernatants 24 h later (b). Cocultures were performed between sorted AM (c) or DC (d) and splenic CD4⁺ T cells purified from air mice. Supernatants were collected 48 h later and levels of IL-17 were evaluated by ELISA. Data represent mean ± SEM (n = 6–10 mice per group per experiment). One representative experiment out of three ones is shown concerning cell sorting and cocultures with T cells.