IN SILICO B-CELL EPITOPE VACCINE DESIGN AND PHYLOGENETIC ANALYSIS OF EBOLA VIRUS ENVELOPE GLYCOPROTEIN

Abstract

Ebola virus (EBOV) is a type of RNA virus from the family of Filoviridae. The 2014-2016 Ebola outbreak in African countries Guinea, Liberia and Sierra Leone has a total of 28,616 cases and 11,310 deaths. People suffering from Ebola disease reported to have symptoms such as fever, body aches, diarrhea and internal and external bleeding. Death from Ebola is mostly caused by multi-organ failure due to internal bleeding and fluid loss. Another Ebola outbreak has spiked this February 2021, suggesting low effectivity of the previous vaccines used. Zaire Ebola virus (EBOV) is known to be the species highly involved on the recent outbreak with a high mortality rate. This study is carried out to design B-cell epitope Ebola vaccine based on the conserved region of Zaire EBOV glycoprotein. Reverse vaccinology and immunoinformatic approaches are used in this study. Samples of Zaire EBOV glycoprotein sequences were retrieved from GenBank, NCBI. The 3D modelling was done by using SWISS-MODEL web server and PyMol software. Phylogenetic tree analysis was also done by using MEGA X. B-cell epitope prediction was done by BepiPred 2.0 and Emini Surface Accessibility using IEDB web server. Epitopes were selected based on its conservancy by comparing the sequences with the MEGA X alignment result. Antigenicity, allergenicity and toxicity properties of the peptides were predicted using VaxiJen 2.0, AllerTOP 2.0 and ToxinPred web servers. In silico cloning was done as the final step using pET-24a(+) expression vector. This study revealed that peptide “LEIKKPD”, “TGFGTNETEYLF”, “PYFGPAA”, “PYFGPA”, and “KLSSTNQL” are the best candidate of B-cell epitope vaccine. Phylogenetic tree and 3D modelling successfully showed the genetic and structural differences of Zaire EBOV GP originating from various countries. In silico cloning was also done using pET28a(+) expression vector to design clone vector map to be used for the next phase of vaccine development.