Vaccine design for outer membrane protein C(Shigella Flexneri)

Shigella flexneri is a highly contagious Gram-negative bacterium that causes severe diarrhea, especially in children under ten years old. Various serotypes in S.flexneri are reported from different regions of the world. The precise approximations of illness and death owing to shigellosis are missing in low socioeconomic countries, although it is widespread in different regions. Outer membrane protein C (OmpC) is located in the outer membrane of Shigella flexneri ۳a and other Gram-negative bacteria of the Enterobacteriaceae family. Recent research and clinical trials report multiple approaches used in Shigella-vaccine development. However, despite the efforts of researchers, pharmaceutical companies and health care organizations, there is no licensed vaccine against shigellosis available to the community. Biodata or bioinformatics is the knowledge of using computer science and statistics and probabilities in the branch of molecular biology. The aim of this research is to design Shigella Flexneri vaccine via in silico approach. The present study unveils OmpC ۳D structure via in silico approaches. Apart from ab initio, other rational methods such as homology modeling and threading were invoked to achieve the purpose. For homology modeling, BLAST was run on the sequence in order to find the best template. The template was then served to model the ۳D structure. In order to vaccine development, attempts should be made to discover peptides that could mimic protein epitopes and possess the same immunogenicity as the whole protein. Subsequently, theoretical methods for epitope prediction exploited to better understanding and characterizing topology, localization, signal peptide sequence, Physical and chemical parameters, single scale amino acid properties and linear and conformational epitopes. In this regard TMHMM, TMBBpred, CELLO, PSLpred, SignalP, Protparam, IEDB, LBtope, SVMtrip and Ellipro servers were applied respectively. In conclusion, amino acids ۲۱۵-۲۲۵ were selected as vaccine candidates. This region contains functional exposed amino acids with higher properties score of B cell epitopes. In these regions, the majority of amino acids are hydrophilic, flexible, accessible, and favorable for B cells with a view to the point of secondary structure.

کلیدواژه ها:

Shigella Flexneri ، epitope ، immunogenicity ، vaccine