In silico analysis of Omp25 and BLS Brucella melitensis antigens for designing subunit vaccine

Abstract

Brucellosis is a well-known infection in domestic animals which caused by Brucella bacterium. Due to<br />serious economic and medical consequences of this disease, various efforts have been made to prevent the<br />infection through the use of recombinant vaccines based on Brucella outer membrane protein (OMP)<br />antigens. The objectives of the present study were cloning, sequencing and epitope prediction of Omp25<br />and BLS genes as two major Brucella melitensis antigens. The full-length open reading frame (ORF) of<br />Omp25 and BLS genes were amplified and cloned into pTZ57R/T vector. Phylogenetic analysis of<br />sequenced genes showed that both genes were nearly similar in different Brucella species. Several online<br />prediction softwares were used to predict B and T-cells epitopes, secondary and tertiary structures,<br />antigenicity ability and enzymatic degradation sites. Bioinformatic tools used in the current study were<br />confirmed by the results of three different experimental epitope predictions. Bioinformatic analysis<br />identified five and two B-cell and two and one T-cell epitopes for Omp25 and BLS antigens, respectively.<br />Finally, according to the antigenicity ability and proteosomal recognition site common B and T-cell epitope<br />was predicted for Omp25 (154-162 amino acids) and BLS (37-48 and 119-139 amino acids). Results of this<br />study might be useful for recombinant vaccine development.