Immunosuppression by a corticosteroid fails to exacerbateHelicobacter pylori infection in a mouse model of gastric colonization

Helicobacter pylori can colonize the human stomach for prolonged periods of time, and this colonization uniformly leads to the development of chronic active gastritis. In a small percentage of individuals, gastric pathology p rogresses to peptic ulceration or more rarely certain gastric cancers. In a ddition to non-specific inflammation, specific systemic and local immunity develops in response to gastric colonization by this pathogen. However, the se responses combined appear inadequate for eliminating H. pylori from the gastric mucosa. This is also the case in a mouse model of gastric colonizat ion by H. pylori. In the present study, we attempted to determine whether t he mammalian host response to infection with H. pylori exerts any overt ant ibacterial effects. To this end we examined H. pylori colonization in norma l mice, and mice immunosuppressed by treatment with a corticosteroid. Despi te obvious suppression of the immune response in the latter mice, H. pylori burdens remained similar in both groups after three months of colonization . This suggests that the murine host response, at least, exerts little obvi ous protection against H. pylori colonization.