Immunoinformatic design of an epitope-based immunogen candidate against Bacillus anthracis

Bacillus anthracis is a highly infectious bacterium and causes anthrax. It infects warm-blooded mammals, likewise its spores have been weaponized and used in biological warfare which has affected many people. Prevention of anthrax remains a great challenge for clinicians. Vaccination is the most hopeful mode and a new generation of epitope-based vaccines has received extended attention. This kind of recombinant vaccine offers an effective and fast response because of the direct targeting of the immune system. Nowadays, collecting epitopes information via in silico tools are highly accurate and simple. In this regard, a variety of the best bioinformatic servers were applied to identify potential B-cell, T-cell, IFN-γ, IL-10, and IL-4 epitopes with no allergenic nor toxic effect. The High-ranked epitopes were selected and fused to each other by GPGPG and EAAAK linkers. They constructed the scaffold along with the L7/L12 adjuvant and 6xHis-tag. The physicochemical properties, secondary and tertiary structures were evaluated, refined, and confirmed using bioinformatics tools. Desirable levels of IgG1, IgG2, T-cytotoxic, T-helper cells, INF-γ, and interleukins were predicted using immune simulation tool. Furthermore, the molecular docking and dynamic simulation between epitopic protein and receptors revealed proper and stable binding affinity. Overall, the engineered recombinant protein can be efficaciously considered as a candidate immunogen