Fig. 2.

Streptococcus pneumoniae infection triggers IL-20 cytokine expression in the lung. Lungs from PBS group and from mice infected with S. pneumoniae(Sp, 2.10⁶ CFU) were collected at 12, 24 and 48h p.i.. (a) Il-19, Il-20, Il-22 and Il-24 mRNA levels were evaluated by RT-qPCR in lung tissue (the cranial lobe) of Spinfected mice and controls. Results were expressed as fold increase compared to the mice exposed to PBS and using expression of Gapdh as a housekeeping gene. (b) Expression of IL-19, IL-20 and IL-24 was evaluated on lung sections by immunohistochemistry (magnification x200) at 24h p.i. Lung sections were prepared from not infected mice (PBS), mice infected with Sp and infected with Sp and treated aby anti-IL-20Rb antibody (Sp + anti-IL-20). Results were expressed as mean ± SEM and statistical analyses were performed by Mann-Whitney U analysis and non-parametric Kruskal-Wallis followed by Dunns posttest in comparison with PBS controls, or with Sp at 48h p.i. *P<.05 and **P<.01. Three independent experiments have been performed with 4-5 mice in each group.