Abstract

Astonishing improvements in information technology, in combination with the valuable experimental data gathered during the past decades, has revolutionized vaccine design strategies. On the other hand, the development of genetic engineering methods has enabled us to design and produce new chimeric proteins for many different purposes, including immunization. In this study we took the advantages of these improvements to develop an efficacious vaccine against three important enteropathogenic bacteria: enterotoixigenic E. coli (ETEC), enterohemorragic E. coli (EHEC), and Shigella. To do this, appropriate immunogens, including subunit B of heat labile toxin and mutated STa toxin from ETEC; EspA and Stx B from EHEC; and the N-terminal part of IpaD, an immunogen from diffrent Shigella strains, were selected. These proteins were fused together by an appropriate peptide linker. Bioinformatic analyses, including the physicochemical parameters calculation, secondary and tertiary structures prediction and verification, antigenic B-cell and T-cell epitopes prediction were performed. Then the protein was reverse-translated to DNA and was codon optimized for expression in E. coli cells. The results showed a proper 3D structure, good theoretical immunogenicity, invitro and invivo stability of the chimeric designed protein and proper structure and stability of the related mRNA. Altogether, the results suggest that the designed chimeric protein, structurally and immunologically, has almost all factors of an efficient vaccine candidate and can be tested in experimental studies.