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Helicobacter pylori infection in mice: Role of outer membrane proteins in colonization and inflammation

Yoshio Yamaoka1, Masakazu Kita, Tadashi Kodama

  • 1Department of Medicine, Veterans Affairs Medical Center and Baylor College of Medicine, Houston, Texas 77030, USA. yyamaoka@bcm.tmc.edu

Gastroenterology
|November 28, 2002
PubMed
Abstract

Insights

Outer membrane protein (OMP) gene status significantly impacts Helicobacter pylori colonization and density in mouse models. Characterizing these genetic variations is crucial for reliable experimental outcomes in H. pylori research.

Area of Science:

  • Microbiology
  • Immunology
  • Gastroenterology

Background:

  • Mouse models of Helicobacter pylori infection exhibit inconsistent colonization and inflammation results.
  • Variability may stem from differences in outer membrane proteins (OMPs) or the cag pathogenicity island (PAI).

Purpose of the Study:

  • To investigate the role of OMP gene switch status and the cag PAI in H. pylori colonization and inflammation variability in mouse models.
  • To determine if specific OMP genes influence bacterial density and host immune response.

Main Methods:

  • C57BL/6 mice were infected with clinical H. pylori isolates and isogenic mutants with varying cag PAI and OMP genotypes.
  • Bacterial density, histology, and mucosal cytokine/chemokine levels were assessed at 4 and 12 weeks post-infection.

Main Results:

  • Switch status of oipA, hopZ, hopO, and hopP genes significantly affected H. pylori density and colonization.
  • Reduced colonization rates (0% vs. 58%) were observed when two or more OMP genes were inactive.
  • oipA knockout mutants led to decreased inflammation and lower levels of IL-6 and KC.
  • A strong correlation (r > 0.7) was found between H. pylori density in human and mouse gastric mucosa.

Conclusions:

  • Subtle genetic variations, such as OMP gene switch status, contribute to variability in H. pylori mouse models.
  • Thorough characterization of H. pylori isolates is essential before and after experimental use.
  • The mouse model is suitable for studying H. pylori colonization, density, and gastric inflammation.

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