A Novel Design of Multi-epitope Vaccine Against Helicobacter pylori by Immunoinformatics Approach

Helicobacter pylori (H. pylori) is a gram-negative spiral bacterium that caused infections in half of the world’s population and had been identified as type I carcinogen by the World Health Organization. Compared with antibiotic treatment which could result in drug resistance, the vaccine therapy is becoming a promising immunotherapy option against H. pylori. Further, the multi-epitope vaccine could provoke a wider immune protection to control H. pylori infection. In this study, the in-silico immunogenicity calculations on 381 protein sequences of H. pylori were performed, and the immunogenicity of selected proteins with top-ranked score were tested. The B cell epitopes and T cell epitopes from three well performed proteins UreB, PLA1, and Omp6 were assembled into six constructs of multi-epitope vaccines with random orders. In order to select the optimal constructs, the stability of the vaccine structure and the exposure of B cell epitopes on the vaccine surface were evaluated based on structure prediction and solvent accessible surface area analysis. Finally Construct S1 was selected and molecular docking showed that it had the potential of binding TLR2, TLR4, and TLR9 to stimulate strong immune response. In particular, this study provides good suggestions for epitope assembly in the construction of multi-epitope vaccines and it may be helpful to control H. pylori infection in the future.