An increased number of gamma/delta T-cells and gastric epithelial cell expression of the groEL stress-protein homologue in Helicobacter pylori-associated chronic gastritis of the antrum.

Numerous studies have shown that the presence of Helicobacter pylori in the stomach is linked to the development of chronic gastritis most commonly seen in the antrum. However, the pathogenic mechanisms are unclear. In 23 of 31 patients, examined due to symptoms from the upper gastrointestinal tract, H. pylori-associated chronic gastritis of the antrum was diagnosed histologically and by growth of H. pylori. Immunoperoxidase staining on gastric biopsy specimens from these patients showed an increased number of gamma/delta T-cells within the epithelium. Furthermore, the Mab ML30 (raised against the 65 kDa heat shock protein of mycobacteria) demonstrated positive staining in the gastric epithelial cells in all H. pylori-positive but not in H. pylori-negative biopsy specimens. H. pylori also reacted with ML30, as detected by immunoperoxidase staining as well as by immunoblotting. Intraepithelial gamma/delta T cells may play a role in host defense against invading H. pylori, and the bacteria may trigger an autoimmune response to stress proteins expressed by the gastric epithelial cells.