Immunobiology of Helicobacter pylori infection

Helicobacter pylori is a ‘slow’ bacterial pathogen. While infection is usually acquired early in life, only decades later does severe pathology appear. During this long period of incubation, the host mounts a vigorous immune response against H. pylori which fails to resolve the infection and may in fact contribute to the severity of the disease. In the past year, evidence has accumulated indicating a role for a polarized T helper 1 cell response in the gastric pathology induced by H. pylori. Furthermore, a pathogenicity island in type I H. pylori strains has been shown to be responsible for H. pylori induced inflammation. Recent advances in animal models have provided the rationale for entering into human clinical trials of an H. pylori vaccine.