Immunoinformatic Approach for Designing Novel Universal Human Peptide Based Vaccine of Glycoprotein Receptor (M protein) against Rift Valley Fever Virus

Rift Valley fever virus (RVFV) is a single strand, negative sense, an envelope spherical particle, of size 80 - 120 nm, segmented RNA virus that belongs to Genus: Phlebovirus of Bunyaviridae family. The clinical manifestations of the disease among animals are abortion and death of newborns. While in humans, although the disease is mild or asymptomatic, there are several reports of high fatality rates. The M segment of RVF virus Genome which encodes the envelope glycoprotein has been used to design a vaccine for immunization against this virus. we aimed to design a novel peptide-based vaccine for RVFV using immunoinformatic approach to predict highly conserved epitopes against glycoprotein receptor" Gn and Gc" of M protein, that can mediate immune response which can use later to produce a new vaccine that could replace the conventional vaccine. A total of 118 sequences of M protein of RVFV were retrieved from NCBI database and stored as FASTA format for immunoinformatics analysis. ClustalW multiple alignment using BioEdit sequence alignment editor (v7.0.9) was performed to the retrieved sequences to identify the conserved region compared to M protein RVFV reference sequence under gene bank accession number [YP_003848705.1]. The B and T cell epitopes prediction is done by immune epitope database (IEDB). (IEDB) predicted B cell epitopes by Bepipred linear epitope prediction analysis and T cell epitopes using Major Histocompatibility Complex class I and ll binding prediction tool based on Stabilized Matrix Method (SMM). Allergenicity for the Helper T cell epitopes (HTL) predicted using AllerTop software. TAP transporter and Proteasomal cleavage for Cytotoxic T cell (CTL) were predicted from (IEDB). The population coverage over the world was determined. The four best predicted CTL namely (836HTYLQSVRK844, 672IPRYSTYLM680, 1085ILHFTVPEV1093 and 834FVHTYLQSV842) were docked with HLA-B*35 and suggested to be universal peptide vaccine for immunization against RVFV. The typical overlapping between the MHC Class I epitope (834FVHTYLQSV842) and MHC Class II (834FVHTYLQSV842) suggest the possibility to presenting these antigens to immune system via both MHC class I and II pathways. In conclusion; the four CTL epitopes are selected as vaccine candidates to develop safer and easier to manufacture without need of culture vaccine for prophylactic method against this virus. We recommend to confirm our result by doing additional in vivo and in vitro complementary steps to support this novel predicted vaccine.