A novel design of a multi-antigenic,multistage and multi-epitope vaccine against Helicobacter pylori: An in silico approach

Helicobacter pylori have colonized the gastric mucosa of half of the population worldwide. This bacterium is classified as a definitive type I carcinogen by the World Health Organization and no effective vaccine has been found against it yet. Thus, a logical and rational vaccine design against H. pylori is necessary. Because of its tremendous complexity and elicited immune responses, the vaccine design should considered multiple antigens to enhance immune-protection, involved in the different stages of pathogenesis besides inducing a specific immune response by B- and T-cell multi-epitopes. In this study, emphasis was placed on the design of a new unique vaccine named CTB-multiHp. In silico techniques were used to design a chimeric construct consisting of cholera toxin B subunit fused to multi-epitope of urease B (residue 148–158, 188–198), cytotoxin-associated gene A (residue 584–602), neutrophil activating protein (residue 4–28), vacuolating cytotoxin gene A (residue 63–81), H. pylori adhesine A (residue77–99), heat shock protein A (residue 32–54) and gamma glutamyl transpeptidase (residue 271–293). The tertiary structure and features of the vaccine were analyzed. The chimeric protein was expressed in Escherichia coli BL21 and the serology analyses indicated that the CTB-multiHp protein produced exhibit immune-reactivity. The results showed that CTB-multiHp could be a good vaccine candidate against H. pylori. Ongoing studies will evaluate the effects of CTB-multiHp against H. pylori infection.