IDENTIFICATION OF NOVEL VACCINE CANDIDATES AGAINST SHIGELLA SPP. THROUGH REVERSE VACCINOLOGY METHODS

Background and Aim:Shigella is among the most important four health-threatening diarrheal diseases in the world. Diarrhea causes by Shigella occurs annually about 165 million around the world and especially in developing countries. Currently, there is no licensed vaccine against Shigella. Current strategies for developing vaccine against Shigella, Such as cellular, hybrid or subunit vaccines have been ineffective. Reverse vaccinology is a new method that explore proteome for novel vaccine candidates. Based on this method the aim of this study is in silico identification of new vaccine candidates against Shigella.Methods:Sequences of extracellular and outer membrane proteins of Shigella (S.flexneri 2a, S.flexneri 5, S.dysenteriae sd197, S.boydii sb227, S.sonnei 53G) were obtained (from Uniprot, Vaxign, and PSORTb). Protein similarity to host-cell, antigenicity and solubility, then were determined (using Vaxijen, PROSO II, and BLASTp). Then high-score proteins were selected and characterized (ProtParam, TMHMM, SignalP and VFDB). Also protein sequences conservation were studied in multiple sequence alignment (BLAST, Clustal and T-Coffee). Finally secondary and tertiary structure of the best proteins were predicted (I-Tasser and Gor IV).Results:Among 550 proteins as potential vaccine candidates, 10 proteins showed highest scores and therefore were selected for experimental Studies.Conclusion:The results indicate that all 10 selected proteins could be used as vaccine candidates. In addition more specialized analysis can be carried out on these proteins such as epitope mapping, truncation, chimerization, combination and optimization for in vitro studies. The results support that reverse vaccinology is a new and appropriate method for discovering new effective antigens.

کلیدواژه ها:

Shigella ، Shigellosis ، Diarrhea ، Reverse Vaccinology ، Bioinformatics