Compensatory Response of IL-1 Gene Knockout Mice After Pulmonary Infection With Klebsiella Pneumoniae

J Med Microbiol. 2005 Jan;54(Pt 1):7-13. doi: 10.1099/jmm.0.45736-0.


This study was designed to determine the role of interleukin (IL)-1 in the inflammatory response against experimentally induced pneumonia caused by Klebsiella pneumoniae. The host immune responses of IL-1 gene knockout (IL-1 KO) mice and immunocompetent wild-type (WT) mice were compared after pulmonary infection with K. pneumoniae. There were no significant differences between the survival rates and viable bacterial counts in lungs and blood of IL-1 KO and WT mice after pulmonary infections under different conditions. Histopathological analysis showed a similar inflammatory response in both groups of mice. However, in the early stage of infection, the level of tumour necrosis factor alpha (TNF-alpha) in homogenized lungs of IL-1 KO mice was significantly higher than in WT mice. To determine the role of endogenous TNF-alpha in the recovery of the defence mechanism in IL-1 KO mice, mice were treated with an anti-TNF-alpha mAb before infection with K. pneumoniae. The results revealed a significantly lower survival rate of anti-TNF-alpha mAb-treated IL-1 KO mice than BSA-treated IL-1 KO mice. The data suggest that compensatory production of TNF-alpha in IL-1 KO mice contributes to the host defence against K. pneumoniae infection.

MeSH terms

  • Animals
  • Blood / microbiology
  • Colony Count, Microbial
  • Disease Models, Animal
  • Interleukin-1 / genetics*
  • Interleukin-1 / immunology*
  • Klebsiella Infections / immunology*
  • Klebsiella pneumoniae / immunology*
  • Klebsiella pneumoniae / isolation & purification
  • Lung / chemistry
  • Lung / microbiology
  • Lung / pathology
  • Male
  • Mice
  • Mice, Knockout
  • Pneumonia, Bacterial / immunology*
  • Pneumonia, Bacterial / microbiology*
  • Survival Analysis
  • Tumor Necrosis Factor-alpha / analysis
  • Tumor Necrosis Factor-alpha / immunology*


  • Interleukin-1
  • Tumor Necrosis Factor-alpha