Epitope-Based Peptide Vaccine Design against Mokola Rabies Virus Glycoprotein G Utilizing In Silico Approaches

Background: Lyssavirus is considered as a neglected, zoonotic and tropical virus. Among all the Lyssavirus species known to exist today, Mokola virus is unique and appears to be exclusive to Africa. This virus is responsible for a meningoencephalomyelitis in mammals therefore; in silico prediction of epitopes of appropriate protein residues is important to produce a peptide vaccine with powerful immunogenic and minimal allergic effect. The aim of this study was to design a vaccine for Mokola virus using its glycoprotein peptides as an immunogen to stimulate protective immune response. Methods and materials: Glycoprotein G Sequences of Mokola was explored from NCBI then the sequences were aligned to obtain conserved regions. The nominees epitopes from Immune Epitope Database were analyzed by different prediction tools for B-cell, T-cell MHC class II and I. Then sequences aligned with the aid of ClustalW implemented in the BioEdit program. Results and conclusions: For Bepipred test of B-cell the total number of conserved epitopes was 85. For Emini surface accessibility prediction, 36 conserved epitopes were passing the default threshold 1.0. In Kolaskar and Tongaonkar antigenicity, 36 conserved epitopes gave score above the default threshold 1.045. However, there are only three epitopes that pass the three tests (LYTIPEK, LAHQK, YPSVPS). The reference glycoprotein strain was analyzed using IEDB MHC-I binding prediction tool to predict T cell epitope. Twenty conserved peptides were predicted to interact with different MHC-I alleles. For MHC-II binding prediction there were 47 conserved epitopes found to interact with MHC-II alleles. The peptides GQILIPEMQ, FRRLSHFRK and FVGYVTTTF had the affinity to bind the highest number of MHC-II alleles. World population coverage for MHC-I most promising 3 peptides FVDLHMPDV, FVGYVTTTF and RLFDGTWVS was 67.42%, while the world population coverage for most promising MHC-II peptides was 99.77%, for the binding to MHC-I and MHC-II, The peptide FVG TTTF world population coverage was 99.31%.