Abstract

Helicobacter pylori are well known as the major gastro-duodenal pathogen of peptic ulcer disease and gastric cancer. Recombinant H. pylori vaccine comprising a single subunit antigen can only induce immune response with limited protection efficiency. Development of oral vaccine would be a new effective strategy for the prevention of H. pylori infection. In this study, the protective effect of H. pylori multicomponent vaccine consisting of UreB and CagA subunit antigens was constructed and investigated in mice. The UreB and CagA gene of H. pylori were inserted into the plasmid pYA3493 and expressed in attenuated Salmonella choleraesuis C500. The UreB and CagA producing strains were then administered orally to mice, contracting to Whole-cell vaccine against H. pylori SS1 infection, and the immune response was assessed by mice immunity IgG ELISA and H. pylori SS1 attack. Noticeable IgG response was induced in the sera of mice orally immunized with S. choleraesuis C500 strain consisting of UreB and CagA subunit antigens. Mice vaccinated orally were significantly protected against gastric Helicobacter infection following a challenge withH. pylori strain SS1. Orally vaccination with the expression of UreB-CagA could prevent gastric infection with H. pylori.

Key words: Helicobacter pylor, orally vaccination, UreB and CagA subunit antigens, mice.