New potent vaccine against brucellosis based on multi-epitope prediction method of inf C protein. In silico study

Purpose

Brucellosis infection could be eradicated by using an effective vaccine. Inf C gene expression generates one of the main Brucella pathogenesis proteins. The purpose of this study was to design a new vaccine against Brucella disease by in silico determination of epitopes of inf C protein.

Methods

In the first, Inf C amino acid sequences were extracted from the UniProt database and subjected to in silico analysis, including multiple sequence alignment, conserved region determination, allergenicity, antigenicity, and toxicity of the selected epitopes for TCL, HTL, and BCl. Vaccine-target (MHC alleles and TLRs) interactions, binding affinities, and dynamical stabilities were inspected through molecular docking and molecular dynamic simulation (MD) using Cluspro 2 server and GROMACS packages respectively. Further, the codon adaptation of the designed vaccine was determined by the JCat server and the obtained sequence was cloned in pET19b(+)vector by pDRAW32 software. Finally, the ability of the newer vaccine to stimulate the immune response was assessed using a computational immune simulation.

Results

Results allowed us to select a peptide vaccine on basis of its good binding affinities with TLR-8 allele. The multi-peptide vaccine showed also to be highly antigenic, non-allergenic, non-toxic, and potential expression in E coli. Results showed also good stability of the vaccine–TLR8 complex and strong cellular and humoral immune response after three in silico injections of the vaccine construct.

Conclusion

All these theoretical results reveal that the conserved region of inf C protein could be used for designing of a new potent vaccine against Brucella.