Role of IL-1β in experimental cystic fibrosis upon P. aeruginosa infection

PLoS One. 2014 Dec 12;9(12):e114884. doi: 10.1371/journal.pone.0114884. eCollection 2014.

Abstract

Cystic fibrosis is associated with increased inflammatory responses to pathogen challenge. Here we revisited the role of IL-1β in lung pathology using the experimental F508del-CFTR murine model on C57BL/6 genetic background (Cftr(tm1eur) or d/d), on double deficient for d/d and type 1 interleukin-1 receptor (d/d X IL-1R1-/-), and antibody neutralization. At steady state, young adult d/d mice did not show any signs of spontaneous lung inflammation. However, IL-1R1 deficiency conferred partial protection to repeated P. aeruginosa endotoxins/LPS lung instillation in d/d mice, as 50% of d/d mice succumbed to inflammation, whereas all d/d x IL-1R1-/- double mutants survived with lower initial weight loss and less pulmonary collagen and mucus production, suggesting that the absence of IL-1R1 signaling is protective in d/d mice in LPS-induced lung damage. Using P. aeruginosa acute lung infection we found heightened neutrophil recruitment in d/d mice with higher epithelial damage, increased bacterial load in BALF, and augmented IL-1β and TNF-α in parenchyma as compared to WT mice. Thus, F508del-CFTR mice show enhanced IL-1β signaling in response to P. aeruginosa. IL-1β antibody neutralization had no effect on lung homeostasis in either d/d or WT mice, however P. aeruginosa induced lung inflammation and bacterial load were diminished by IL-1β antibody neutralization. In conclusion, enhanced susceptibility to P. aeruginosa in d/d mice correlates with an excessive inflammation and with increased IL-1β production and reduced bacterial clearance. Further, we show that neutralization of IL-1β in d/d mice through the double mutation d/d x IL-1R1-/- and in WT via antibody neutralization attenuates inflammation. This supports the notion that intervention in the IL-1R1/IL-1β pathway may be detrimental in CF patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bronchoalveolar Lavage Fluid / microbiology
  • Cystic Fibrosis / immunology*
  • Cystic Fibrosis / microbiology*
  • Cytokines / metabolism
  • Histological Techniques
  • Interleukin-1beta / metabolism*
  • Lung / metabolism
  • Lung / pathology*
  • Mice
  • Mice, Inbred CFTR
  • Mice, Knockout
  • Neutrophils / immunology
  • Pseudomonas Infections / immunology*
  • Pseudomonas Infections / physiopathology
  • Pseudomonas aeruginosa*
  • Receptors, Interleukin-1 Type I / genetics
  • Signal Transduction / immunology*
  • Statistics, Nonparametric
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • Cytokines
  • IL1R1 protein, mouse
  • Interleukin-1beta
  • Receptors, Interleukin-1 Type I
  • Tumor Necrosis Factor-alpha

Grants and funding

This study was part of the European project n°10IM1016 financed by the French association “Vaincre La Mucoviscidose”, supported by the ERASMUS Medical Center of Rotterdam (The Netherlands), and by Région Centre (Respig project) and CNRS of Orléans (France). RBO was supported by the Dutch CF foundation NCFS; MS was supported by the Dutch Lung foundation (Longfonds 3.3.10.027). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.