Therapeutic immunization against Helicobacter pylori infection in BALB/c mice induced by a multi-epitope vaccine based on computer-aided design

BackgroundCombined antibiotic regimens have caused problems such as increasing antimicrobial resistance to H. pylori and intestinal flora disturbance. Vaccination is a great alternative approach, but also faces the limited immune response induced by monovalent vaccines. Therefore, the development of multi-epitope vaccines is promising immunotherapy to control H. pylori infection. ObjectiveTo develop a multi-epitope vaccine and evaluate its therapeutic efficacy against H. pylori infection. Materials and MethodsThe B and T cell epitopes from UreB, FlaA, AlpB, SabA, and HpaA were linked for producing 2 multi-epitope vaccines (CTB-S3 and CTB-S5) by a structural evaluation based on computer-aided design. The abilities to produce antigen-specific antibodies and neutralizing antibodies of CTB-S3 and CTB-S5 were evaluated in BALB/c mice. After that, their therapeutic efficacy was explored in H. pylori-infected mice. ResultsCTB-S3 or CTB-S5 could induce high levels of specific antibodies against UreB, FlaA, AlpB, SabA, HpaA, and neutralizing antibodies against H. pylori urease and adhesion. Also, oral therapeutic immunization with CTB-S3 or CTB-S5 could decrease H. pylori colonization and reduce stomach damage; the protection was correlated with H. pylori-specific IgG, SIgA antibodies, and CD4+ T cell immune response. ConclusionsOur study developed a multi-epitope vaccine based on a computer-aided design. The CTB-S3 and CTB-S5 vaccines may be promising therapeutic candidate vaccines against H. pylori infection and provide a reference for vaccine design of other pathogens.