B-Cell Conserved Epitope Screening and In Silico Cloning of Envelope Glycoprotein from Ebola Virus (EBOV) For Vaccine Candidate Construction

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. Death from Ebola is mainly caused by multi-organ failure due to internal bleeding and fluid loss. Another Ebola outbreak spiked this February 2021, suggesting the low effectiveness of the previous vaccines used. Zaire Ebola virus (EBOV) is known to be the species highly involved in the recent outbreak with a high mortality rate. This study is carried out to design a B -cell epitope Ebola vaccine based on the conserved region of Zaire EBOV glycoprotein. Reverse vaccinology and immunoinformatics approaches are used in this study. Samples of Zaire EBOV glycoprotein sequences were retrieved from GenBank, NCBI. The 3D modeling was done using the SWISS -MODEL web server and PyMol software. Phylogenetic tree analysis was also done using MEGA X. B-cell epitope prediction was done by BepiPred 2.0 and Emini Surface Accessibility using the IEDB web server. Epitopes were selected based on their 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 the pET-24a(+) expression vector. This study revealed that peptides "LEIKKPD," "TGFGTNETEYLF," "PYFGPAA," "PYFGPA," and "KLSSTNQL" are the best candidate for the B-cell epitope vaccine. Phylogenetic tree and 3D modeling successfully showed the genetic and structural differences of Zaire EBOV GP originating from various countries. In silico cloning was also done using the pET28a(+) expression vector to design a clone vector map for the next vaccine development phase.