Role of interleukin-1 in the pulmonary immune response during Pseudomonas aeruginosa pneumonia

Am J Physiol Lung Cell Mol Physiol. 2002 Feb;282(2):L285-90. doi: 10.1152/ajplung.00461.2000.


Pneumonia is associated with elevated concentrations of the proinflammatory cytokine interleukin (IL)-1 in the pulmonary compartment. To study the role of IL-1 in the pathogenesis of Pseudomonas pneumonia, IL-1 receptor type 1 gene-deficient (IL-1R -/-) mice and wild-type mice were intranasally inoculated with Pseudomonas aeruginosa. The absence of the IL-1 signal attenuated the outgrowth of Pseudomonas in lungs, as reflected by an increasing number of colony-forming units (cfu) during Pseudomonas pneumonia in wild-type mice and a concurrently decreasing number of cfu during pulmonary infection in IL-1R -/- mice (P < 0.05, IL-1R -/- mice vs. wild-type mice). Influx of neutrophils was decreased in bronchoalveolar lavage fluids in IL-1R -/- mice compared with wild-type mice. Similarly, lung levels of cytokines (tumor necrosis factor-alpha, IL-6) and chemokines (macrophage inflammatory protein-2 and KC) were lower in IL-1R -/- mice 24 h postinoculation. Consistent with results obtained in IL-1R -/- mice, treatment of wild-type mice with IL-1R antagonist also diminished outgrowth of Pseudomonas when compared with wild-type mice treated with vehicle (P < 0.05). These results demonstrate that an absence or reduction in endogenous IL-1 activity improves host defense against Pseudomonas pneumonia while suppressing the inflammatory response.

MeSH terms

  • Animals
  • Chemokine CXCL1
  • Chemokine CXCL2
  • Chemokines / metabolism
  • Chemokines, CXC*
  • Chemotactic Factors / metabolism
  • Female
  • Growth Substances / metabolism
  • Intercellular Signaling Peptides and Proteins*
  • Interleukin 1 Receptor Antagonist Protein
  • Interleukin-1 / immunology*
  • Interleukin-1 / metabolism
  • Interleukin-6 / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Pneumonia, Bacterial / drug therapy
  • Pneumonia, Bacterial / immunology*
  • Pneumonia, Bacterial / metabolism
  • Pseudomonas Infections / drug therapy
  • Pseudomonas Infections / immunology*
  • Pseudomonas Infections / metabolism
  • Pseudomonas aeruginosa*
  • Receptors, Interleukin-1 / genetics*
  • Sialoglycoproteins / pharmacology
  • Tumor Necrosis Factor-alpha / metabolism


  • Chemokine CXCL1
  • Chemokine CXCL2
  • Chemokines
  • Chemokines, CXC
  • Chemotactic Factors
  • Cxcl1 protein, mouse
  • Cxcl2 protein, mouse
  • Growth Substances
  • Il1rn protein, mouse
  • Intercellular Signaling Peptides and Proteins
  • Interleukin 1 Receptor Antagonist Protein
  • Interleukin-1
  • Interleukin-6
  • Receptors, Interleukin-1
  • Sialoglycoproteins
  • Tumor Necrosis Factor-alpha