Open AccessReduced activation of inflammatory responses in host cells by mouse‐adapted Helicobacter pylori isolates
Author(s) -
Philpott Dana J.,
Belaid Djilali,
Troubadour Pascale,
Thiberge JeanMichel,
Tankovic Jacques,
Labigne Agnès,
Ferrero Richard L.
Publication year - 2002
Publication title -
cellular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.542
H-Index - 138
eISSN - 1462-5822
pISSN - 1462-5814
DOI - 10.1046/j.1462-5822.2002.00189.x
Subject(s) - biology , helicobacter pylori , microbiology and biotechnology , pathogenicity island , secretion , inflammation , phenotype , bacteria , in vivo , interleukin 8 , gene , genotype , immunology , virulence , genetics , biochemistry
Summary Helicobacter pylori strains that harbour the Cag pathogenicity island (Cag PAI) induce interleukin (IL)‐8 secretion in gastric epithelial cells, via the activation of NF‐ κ B, and are associated with severe inflammation in humans. To investigate the influence of Cag PAI‐mediated inflammatory responses on H. pylori adaptation to mice, a selection of H. pylori clinical isolates ( n = 12) was cag PAI genotyped and tested in co‐culture assays with AGS gastric epithelial cells, and in mouse colonization studies. Six isolates were shown to harbour a complete cag PAI and to induce NF‐ κ B activation and IL‐8 secretion in AGS cells. Of the eight isolates that spontaneously colonized mice, six had a cag PAI – genotype and did not induce pro‐inflammatory responses in these cells. Mouse‐to‐mouse passage of the two cag PAI + ‐colonizing strains yielded host‐adapted variants that infected mice with bacterial loads 100‐fold higher than those of the respective parental strains ( P = 0.001). These mouse‐adapted variants were affected in their capacity to induce pro‐inflammatory responses in host cells, yet no changes in cag PAI gene content were detected between the strains by DNA microarray analysis. This work provides evidence for in vivo selection of H. pylori bacteria with a reduced capacity to induce inflammatory responses and suggests that such bacteria are better adapted to colonize mice.