Helicobacter pylori induces cell cycle arrest of T-lymphocytes

Helicobacter pylori leads to a chronic and potentially fatal inflammation of the gastric mu-cosa. We investigated the interaction of H. pylori with human lymphocytes in order to identify possible mechanisms of immune evasion. T- and B-lymphocytes were isolated from H. pylori infected patients and uninfected controls and stimulated with anti-CD3/CD28 or IL–6. Prolif-eration of lymphocytes was abolished upon co-incubation with different H. pylori strains at 1–5 bacteria per cell or with protein extracts of culture supernatants. Inhibition of proliferation was independent of known virulence factors. Characterizatio…