HELICOBACTER-PYLORI ADHESINS

Aim: To examine published data on the mechanisms that allow Helicobact er pylori to adhere to the human gastric epithelium, thus promoting pe rsistent colonization. Method: Survey of published studies. Results: H . pylori contain a number of cell surface proteins which can be releas ed by various treatments (water wash, acid-glycine or mild detergents) . Various surface haemagglutinins have been identified, including (1) a fimbrial sialic acid-specific haemagglutinin and (2) afimbrial cell surface haemagglutinins with sialic acid and unidentified sugar specif icities. Glycolipid-binding surface proteins (probably not involved in haemagglutination) are also adhesins for various tissue-culture cell lines. Finally, a class of sulphated carbohydrate polymers react with H. pylori surface components which, in turn, react with sulphomucins, sulphated glycolipids and heparin sulphate, and may allow the microbe to colonize the mucin layer and penetrate the gastric epithelium. Conc lusion: Recent research has identified a number of mechanisms that bin d both spiral and coccoidal forms of H. pylori to extracellular matrix components such as laminin, vitronectin and type IV collagen. This ma y provide important tissue adhesins in chronic H. pylori infection, al lowing the pathogen to protect itself from attack by the immune system in subepithelial gastric tissues.