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

Departments of 1 Experimental Internal Medicine, 2 Intensive Care Medicine, 3 Pathology, and 6 Infectious Diseases, Tropical Medicine, and AIDS , Academic Medical Center of Amsterdam, 1105 AZ Amsterdam, The Netherlands; 4 Amgen, Incorporated, Thousand Oaks, California 91320; and 5 University of Colorado Health Sciences Center, Denver, Colorado 80262 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