Superficial Components from Helicobacter pylori That Are Adherent to Epithelial Cells

The presence of Helicobacter pylori in the human stomach has been highly associated with gastritis and peptic ulcer disease [1–4]. Adherence of H. pylori to gastric cells of infected patients has been directly observed and may be important in the maintenance of infection [5–8]. The attachment of H. pylori to gastric cells may involve bacterial components able to bind to specific cellular receptors. The cellular receptors may be restricted to the gastric cells explaining the exclusive association of H. pylori with those cells, but the specificity of H. pylori for the gastric mucosa may also result from the particular micro-environment of the stomach; in that case, the cellular receptors binding H. pylori could be present on other human cells. It is thus reasonable to study the colonization factors of H. pylori using epithelial cell lines as has been previously described [8–10]. Using microtiter assays, we previously reported [11] a bacterial material easily extracted from the surface of H. pylori which included components that specifically adhered to HeLa cell membranes. This superficial adhering material (SAM) binds to a cellular receptor unrelated to N-acety1-neuraminic acid and is thus different from the N-acetyl-neuraminyl-lactose-binding hemagglutinin previously described [12]. By gel exclusion chromatography, the adhering components of SAM copurify with urease activity in fractions which included antigens of 60, 52, 30, and 15 kDa. In this work, we further identified the adhering components of SAM and we examined the fate of viable epithelial cells coated with these adhering bacterial components.