New microbicidal functions of tracheal glands: defective anti-infectious response to Pseudomonas aeruginosa in cystic fibrosis

PLoS One. 2009;4(4):e5357. doi: 10.1371/journal.pone.0005357. Epub 2009 Apr 28.

Abstract

Tracheal glands (TG) may play a specific role in the pathogenesis of cystic fibrosis (CF), a disease due to mutations in the cftr gene and characterized by airway inflammation and Pseudomonas aeruginosa infection. We compared the gene expression of wild-type TG cells and TG cells with the cftr DeltaF508 mutation (CF-TG cells) using microarrays covering the whole human genome. In the absence of infection, CF-TG cells constitutively exhibited an inflammatory signature, including genes that encode molecules such as IL-1alpha, IL-beta, IL-32, TNFSF14, LIF, CXCL1 and PLAU. In response to P. aeruginosa, genes associated with IFN-gamma response to infection (CXCL10, IL-24, IFNgammaR2) and other mediators of anti-infectious responses (CSF2, MMP1, MMP3, TLR2, S100 calcium-binding proteins A) were markedly up-regulated in wild-type TG cells. This microbicidal signature was silent in CF-TG cells. The deficiency of genes associated with IFN-gamma response was accompanied by the defective membrane expression of IFNgammaR2 and altered response of CF-TG cells to exogenous IFN-gamma. In addition, CF-TG cells were unable to secrete CXCL10, IL-24 and S100A8/S100A9 in response to P. aeruginosa. The differences between wild-type TG and CF-TG cells were due to the cftr mutation since gene expression was similar in wild-type TG cells and CF-TG cells transfected with a plasmid containing a functional cftr gene. Finally, we reported an altered sphingolipid metabolism in CF-TG cells, which may account for their inflammatory signature. This first comprehensive analysis of gene expression in TG cells proposes a protective role of wild-type TG against airborne pathogens and reveals an original program in which anti-infectious response was deficient in TG cells with a cftr mutation. This defective response may explain why host response does not contribute to protection against P. aeruginosa in CF.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / metabolism
  • Cells, Cultured
  • Cystic Fibrosis / genetics*
  • Cystic Fibrosis / immunology*
  • Cystic Fibrosis / metabolism
  • Cystic Fibrosis / microbiology
  • Cystic Fibrosis Transmembrane Conductance Regulator / genetics
  • Cytokines / genetics
  • Gene Expression
  • Gene Expression Profiling
  • Humans
  • Inflammation Mediators / metabolism
  • Mutation
  • Oligonucleotide Array Sequence Analysis
  • Pseudomonas aeruginosa / metabolism
  • Pseudomonas aeruginosa / pathogenicity
  • Sphingolipids / metabolism
  • Trachea / immunology*
  • Trachea / metabolism
  • Trachea / microbiology

Substances

  • Bacterial Proteins
  • CFTR protein, human
  • Cytokines
  • Inflammation Mediators
  • Sphingolipids
  • Cystic Fibrosis Transmembrane Conductance Regulator