Dysregulated interleukin-8 secretion and NF-kappaB activity in human cystic fibrosis nasal epithelial cells

J Cyst Fibros. 2006 May;5(2):113-9. doi: 10.1016/j.jcf.2005.12.003. Epub 2006 Feb 14.


Background: It is not clear whether cystic fibrosis (CF) airway inflammation is a consequence of bacterial infection or is intrinsically dysregulated. The aim of this study was to investigate IL-8 secretion and NF-kappaB activity in primary respiratory epithelial cells cultured from nasal polyps obtained from CF and non-CF subjects.

Methods: NF-kappaB activity was studied by electrophoretic mobility-shift and quantitative colorimetric assays in nuclear extracts. Immunoreactive IL-8 levels were assessed by ELISA in cell culture supernatants. Both parameters were studied at baseline and following challenge with Pseudomonas aeruginosa or stimulation with pro-inflammatory cytokines.

Results: Under basal conditions, CF cells presented a significant higher activity of NF-kappaB than non-CF cells (P=0.0004). P. aeruginosa challenge and IL-1beta/H2O2 co-stimulation caused four and two fold induction of NF-kappaB activity in non-CF and CF cells, respectively. IL-8 levels in unstimulated CF cells were significantly higher than in non-CF cells (P=0.0025). Upon incubation with P. aeruginosa and IL-1beta/H2O2, non-CF cells produced 6.3 times more IL-8 than unstimulated cells, whereas IL-8 secretion increased only of 1.4 times in CF cells.

Conclusions: CF respiratory epithelial cells exhibit a basal dysregulated production of IL-8 that partially correlates to enhanced NF-kappaB activity. Our data corroborate the hypothesis of a basal exaggerated inflammatory response in the CF respiratory epithelium.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cells, Cultured
  • Cystic Fibrosis / metabolism*
  • Humans
  • Hydrogen Peroxide / pharmacology
  • Interleukin-1 / pharmacology
  • Interleukin-8 / metabolism*
  • NF-kappa B / metabolism*
  • Nasal Mucosa / drug effects
  • Nasal Mucosa / metabolism*
  • Nasal Mucosa / microbiology
  • Pseudomonas aeruginosa / physiology


  • CXCL8 protein, human
  • Interleukin-1
  • Interleukin-8
  • NF-kappa B
  • Hydrogen Peroxide