Introduction of a Novel Poly-Epitope Vaccine Against Mycobacterium tuberculosis Infection; an Immunoinformatics Approach

Abstract

Background: Tuberculosis is known as one of the most dangerous diseases caused by Mycobacterium tuberculosis. Although different strategies have been applied to prevent this disease, it is still considered a killer disease in the world. Objectives: This project was conducted to design a novel poly-epitope vaccine based on three antigenic proteins against tuberculosis. Methods: To design a poly-epitope vaccine, first, the antigenic proteins of Mycobacterium tuberculosis, including Dnak, FbpA, and katG were selected from the database. Then, B cell, MHCI, and MHCII epitopes of the antigenic proteins were predicted using reliable online tools. The best-predicted epitopes were applied to assemble a poly-epitope vaccine. The physicochemical features, the antigenicity of the whole vaccine, and the protein structures of the designed poly-epitope vaccine were evaluated by the most precise tools. Also, the coding DNA sequence of the vaccine was adapted for expression in the prokaryotic system, then, it was theoretically cloned in pET32a (+) vector. Results: The results revealed that the molecular weight and length of the designed poly-epitope vaccine were 32 kDa and 308 amino acids, respectively. The protein structure results demonstrated that the designed poly-epitope vaccine contained 19.48% alpha-helix and 73.05% random coil. Also, the results showed that 92.2% of amino acid residues were located in the favored region. Finally, it was clarified that the antigenicity of the designed poly-epitope vaccine was 12333. Conclusions: According to the results of the current project, it seems that the designed poly-epitope vaccine can be an appropriate candidate to control tuberculosis.