Enhancement of adherence of Helicobacter pylori to host cells by virus: possible mechanism of development of symptoms of gastric disease.

It remains unclear why gastric disease does not develop in all cases of Helicobacter pylori infection. In this study, we analyzed whether simian virus 5 (SV5) enhanced adherence of H. pylori to adenocarcinoma epithelial cells (AGS). H. pylori in AGS (harboring SV5) and SV5-infected Vero cells, and an agglutination of H. pylori mixed with SV5 were observed by light microscopy, scanning and transmission electron microscopies. The adherent rate of H. pylori to SV5-infected Vero cells and treated with an anti-SV5 antibody was determined. H. pylori adhered to the surface of AGS cells near SV5 particles, as shown by scanning and transmission electron microscopies. The adherence of H. pylori to SV5-infected Vero cells was significantly enhanced compared with that to Vero cells. In contrast, the adherence of H. pylori to Vero cells was decreased by treatment with the anti-SV5 antibody. Agglutination of H. pylori mixed with SV5 was observed by scanning and transmission electron microscopies. Agglutination did not occur when SV5 was treated with the anti-SV5 antibody before mixing. These findings demonstrated that SV5 enhanced the adherence of H. pylori to host cells, suggesting that a persistently infected virus may be a factor enhancing the pathogenicity of H. pylori in humans.