Study of Helicobacter pullorum proinflammatory properties on human epithelial cells in vitro

Gut. 2009 May;58(5):629-35. doi: 10.1136/gut.2007.144501. Epub 2008 Jun 25.


Background and aims: Helicobacter pullorum is an enterohepatic Helicobacter species of avian origin detected in patients with acute diarrhoea and inflammatory bowel disease. The aim of the present study was to determine whether H pullorum exerts a direct effect on human intestinal epithelial cells in vitro and to characterise the bacterial mechanisms and the signalling pathways involved.

Materials and methods: The proinflammatory properties of H pullorum from human and avian origins were measured on human gastric (AGS) and intestinal (CaCo-2 and HT-29) epithelial cell lines after co-culture with different H pullorum strains, and the extent of nuclear factor-kappaB (NF-kappaB) involvement was determined.

Results: All of the H pullorum strains tested stimulated interleukin 8 (IL8) secretion by the three cell lines. Similar results were obtained with heat-killed H pullorum. Incubation of cells with filtered H pullorum culture supernatants did not stimulate IL8 secretion. The same observation was made when bacterial adherence was inhibited by Transwell inserts. H pullorum induced NF-kappaB activation and rapid nuclear translocation as demonstrated by immunofluorescent staining and cellular fractionation. NF-kappaB involvement was confirmed by using the specific inhibitor SN50 and small interfering RNA (siRNA) which abolished H pullorum-induced IL8 production.

Conclusions: H pullorum strains stimulate IL8 secretion by human gastric and intestinal epithelial cell lines. This effect requires bacterial adherence and probably lipopolysaccharides, and is mediated by NF-kappaB signalling. The present study strengthens the argument that H pullorum is a potent human pathogen and highlights its putative role in acute and chronic digestive diseases such as inflammatory bowel disease.

MeSH terms

  • Animals
  • Bacterial Adhesion / physiology
  • Blotting, Western
  • Caco-2 Cells
  • Cell Nucleus / metabolism
  • Epithelial Cells / metabolism
  • Epithelial Cells / microbiology*
  • HT29 Cells
  • Helicobacter / pathogenicity*
  • Helicobacter pylori / pathogenicity
  • Humans
  • Interleukin-8 / metabolism*
  • Intestinal Mucosa / cytology
  • Intestinal Mucosa / metabolism
  • NF-kappa B / metabolism*
  • Poultry / microbiology
  • Signal Transduction


  • Interleukin-8
  • NF-kappa B