Chlamydia pneumoniae infection in IL-10 knock out mice: accelerated clearance but severe pulmonary inflammatory response.

In interleukin-10 knock out (IL-10 KO) mice, accelerated clearance of pulmonary Chlamydia pneumoniae infection was observed. On the other hand, the histopathological changes in lung tissue were more pronounced in IL-10 KO mice at all time points after infection and repeated infection than in the wild type mice. Both ex vivo induced antigen-specific proliferation as well as production of proinflammatory cytokines by splenocytes were higher in IL-10 KO mice than in WT mice. Also, intrapulmonary proinflammatory cytokine levels were higher in IL-10 KO mice than in the WT mice. The lack of anti-inflammatory action of IL-10 is likely to contribute to the enhanced clearance but severe inflammation in this experimental model.