Urease is an effective target for design of a therapeutic
epitope vaccine against Helicobacter pylori (H. pylori). In our previous studies, an
epitope vaccine CTB-UE containing Th and B
epitopes from H. pylori
urease was constructed, and the CTB-UE
vaccine could provide
therapeutic effect on H. pylori
infection in mice. However, a
multivalent vaccine, combining different
antigens participating in different aspects of H. pylori colonization and pathogenesis, may be more effective as a therapeutic
vaccine than a univalent
vaccine targetting
urease. Therefore, a multivalent
epitope vaccine FVpE, containing Th1-type immune adjuvant NAP, three selected functional fragments from CagA and VacA, and an
urease multi-
epitope peptide (UE) from CTB-UE, was constructed in this study and expected to obtain better sterilizing immunity than the univalent
epitope vaccine CTB-UE. The
therapeutic effect of multivalent
epitope vaccine FVpE with
polysaccharide adjuvant (PA) was evaluated in H. pylori-infected Mongolian gerbil model. The results showed that both FvpE and CTB-UE
vaccine could induce similar levels of specific
antibodies against H. pylori
urease, and had similar inhibition effect on H. pylori
urease activity. However, only FVpE could induce high levels of specific
antibodies to CagA, VacA, and NAP. In addition, oral therapeutic immunization with FVpE plus PA significantly reduced the number of H. pylori colonies in the stomach of Mongolian gerbils compared with oral immunization with CTB-UE plus PA, or FVpE only, and the FVpE
vaccine with PA even exhibited sterilizing immunity. The protection of FVpE was related to the mixed CD4+ T cell responses and
epitope-specific
antibodies against various H. pylori
antigens. These results indicate that a multivalent
epitope vaccine targetting various H. pylori
antigens could be a promising candidate against H. pylori
infection.