The neutralization of endogenous IL-9 has significant impact on infection process and histopathology in the lung.

<p>C57BL/6 mice were intranasally administered with 10μg of either anti-mouse IL-9 mAb or isotype control antibody at one day before and the same day of infection following by every 2 days thereafter. Mice were inoculated intranasally with 1×10³ IFUs of Cm EBs. (A) The percentage of body weight changes in the two groups of mice. (B) Live chlamydial organisms (IFUs) in the lung on day 7 and day 14 after infection in each group. (C) The lung tissue sections from different experiment groups were tained with H&E and observed under light microscopy. (D) Semi-quantitative analysis of lung inflammation and damage (pathological score). Slides were examined by a blinded pathologist and the inflammatory grades were analyzed as described in Materials and Methods. One representative experiment of three independent experiments (four mice in each group in each experiment) is shown. The results are shown as mean ± SD.