Research

In silico analysis of chimeric espA, eae and tir fragments of Escherichia coli O157:H7 for oral immunogenic applications

Jafar Amani^1,2 , S Latif Mousavi³ , Sima Rafati⁴ and Ali H Salmanian¹

¹  National Institute of Genetic Engineering and Biotechnology (NIGEB), Shahrak-e- Pajoohesh, 15th Km, Tehran -Karaj Highway, Tehran, IR Iran

²  Baqiyatallah University of Medical Science, Department of Biotechnology, Tehran, IR Iran

³  Department of Biology, Faculty of Basic Sciences, Shahed University, Tehran, IR Iran

⁴  Molecular Immunology and Vaccine Research Laboratory, Department of Immunology, Pasteur Institute of Iran, Tehran, IR Iran

author email corresponding author email

Theoretical Biology and Medical Modelling 2009, 6:28doi:10.1186/1742-4682-6-28

Published:	8 December 2009

Abstract

Background

In silico techniques are highly suited for both the discovery of new and development of existing vaccines. Enterohemorrhagic Escherichia coli O157:H7 (EHEC) exhibits a pattern of localized adherence to host cells, with the formation of microcolonies, and induces a specific histopathological lesion (attaching/effacing). The genes encoding the products responsible for this phenotype are clustered on a 35-kb pathogenicity island. Among these proteins, Intimin, Tir, and EspA, which are expressed by attaching-effacing genes, are responsible for the attachment to epithelial cell that leads to lesions.

Results

We designed synthetic genes encoding the carboxy-terminal fragment of Intimin, the middle region of Tir and the carboxy-terminal part of EspA. These multi genes were synthesized with codon optimization for a plant host and were fused together by the application of four repeats of five hydrophobic amino acids as linkers. The structure of the synthetic construct gene, its mRNA and deduced protein and their stabilities were analyzed by bioinformatic software. Furthermore, the immunogenicity of this multimeric recombinant protein consisting of three different domains was predicted.

Conclusion

a structural model for a chimeric gene from LEE antigenic determinants of EHEC is presented. It may define accessibility, solubility and immunogenecity.