Design of a Trivalent DC-inducing mRNA Vaccine Against Monkeypox, Cowpox, and Vaccinia Viruses: A computational approach

In silico Immunogenic Protein Design Against Monkeypox

Abstract

Monkeypox virus (MPXV) is a novel virus that has been disseminated around the globe and caused human disease. Over 86 thousand infection cases have been reported, which has concerned the World Health Organization (WHO). Given the challenges faced due to the spread of MPXV, an immune-mediating therapy to prevent infection by MPXV is invaluable to aid large-scale public health practices. In this field, the mRNA vaccine could be a sufficient way to control the virus's transmissibility around worldwide study; we used immunoinformatic approaches that aided the pathway to develop the novel mRNA vaccine. In the first step, we gathered three key proteins (A35R, cell surface binding, and M1R) conserved in Cowpox as well as Vaccinia viruses for the design of vaccines and computed the potent immunogen epitopes that the engineered vaccines assemble with the fused finalized epitopes and Beta-defensin 3 adjuvant that is a major stimulation of dendritic cells (DCs), along with the PADRE and TAT sequences were added. The vaccine construct was modeled with Robetta tool and validated by PROCHECK, ERRAT, and Z-score. Physicochemical properties were also investigated and confirmed to be favorable. Disulfide engineering, immunological simulation, and molecular docking with TLR3 were performed. Finally, the construction of mRNA was designed in silico, the mRNA vaccine structure was predicted, and then the molecular dynamics simulation was performed to investigate the TLR3-vaccine complex. The eighteen final epitopes were predicted. The engineered multi-epitope protein, entails 350 amino acids and had good structural quality, as quantified through an ERRAT value over 99%. Also, engineering of disulfide bond was performed in order to augment the construct stability of the MPXV vaccine. The Ramachandran analysis was utilized to further corroborate the favorable φ (phi) and ψ (psi) angles, with the aminoacids localized to the highly favorable or permitted regions.  The design of the mRNA construct was achieved by incorporating the 5’UTR, start codon, signal peptide, open reading frames, stop codon,3’UTR, and polyA. In addition, the immune simulation showed sustained immune response. Also, the molecular dynamic simulation (MDS) and energy analyses suggested that the vaccine-TLR3 complex binding was stable. An mRNA vaccine was designed to provoke a robust immune response against MPXV while offering immunoprotection against Cowpox and Vaccinia. The present work analyzed the structure of a novel multi-epitope vaccine, which indicated it could be an effective option against MPXV infection. Future study is recommended to confirm the immunomodulatory role of the designed MPXV vaccine.