Interaction of Helicobacter pylori with C-Type Lectin Dendritic Cell-Specific ICAM Grabbing Nonintegrin

In this study we asked whether Helicobacter pylori whole cells and lipopolysaccharide (LPS) utilize sugar moieties of Lewis (Le) antigenic determinants to interact with DC-SIGN (dendritic cell specific ICAM grabbing nonintegrin) receptor on dendritic cells (DCs). For this purpose the soluble DC-SIGN/Fc adhesion assay and the THP-1 leukemia cells with induced expression of DC-SIGN were used. We showed that the binding specificity of DC-SIGN with H. pylori Le(X/Y) positive whole cells and H. pylori LPS of Le(X/Y) type was fucose dependent, whereas in Le(XY) negative H. pylori strains and LPS preparations without Lewis determinants, this binding was galactose dependent. The binding of soluble synthetic Le(X) and Le(Y) to the DC-SIGN-like receptor on THP-1 cells was also observed. In conclusion, the Le(XY) dependent as well as independent binding of H. pylori whole cells and H. pylori LPS to DC-SIGN was described. Moreover, we demonstrated that THP-1 cells may serve as an in vitro model for the assessment of H. pylori-DC-SIGN interactions mediated by Le(X) and Le(Y) determinants.