Design of a multiepitope vaccine encoding T-lymphocyte and B-lymphocyte epitopes for preventing Brucella melitensis infections

Objective(s): Brucellosis, especially caused by Brucella melitensis, is a disease that causes severe economic losses for livestock farms worldwide and remains one of the most common zoonotic diseases with more than 500,000 human cases reported annually. Immunity against Brucella melitensis involves antigenspecific CD4+ and CD8+ T-cells activation and humoral immune responses. The commonly used live attenuated vaccine in ovine brucellosis prophylaxis is B. melitensis Rev1, but due to different problems caused by the administration of this vaccine, a protective subunit vaccine against B. melitensis is strongly demanded. The outer membrane proteins (OMPs) of Brucella spp. have been characterized as potential immunogenic and protective antigen. Trigger factor protein is a cytoplasmic protein which has also been reported to act as a protective and a good immunogenic antigen. Brucella Omp25, Omp31 and TF proteins have shown a considerable potential as protective antigens for brucellosis.Materials and Methods: In this study, a wide range of on-line prediction software such as Vaxijen,Iedb,Syfpeithi, Netmhc, Propred, BCPredwas used to predict B and T-cells epitopes, secondary structure and antigenicity TF, OMP25 and OMP31 antigens. Results and Conclusion: Bioinformatics analysis was identified common between Band T cell epitopesat amino acid (AA) residues 69-96, 120-136, 304-315and 353-371 for TF protein and 26-45, 59-79, 89-109, 122-131, 154-163, 176-196 and 204-213 for OMP25 and5-29, 53-90, 167-180 and 185-205 for OMP31. This analysis showed that this region has proper epitope characterization and so may be useful for producing recombinant vaccine.,