In silico designing of multi-epitope vaccine construct against human coronavirus infections.

Single stranded RNA viruses were known to cause variety of diseases since many years and are gaining much importance due to pandemic after the identification of a novel corona virus (severe acute respiratory syndrome-coronavirus (SARS-CoV-2)). Seven coronaviruses (CoVs) are known to infect humans and they are OC43 CoV, NL63 CoV, HKU1 CoV, Middle East respiratory syndrome, SARS CoV, and SARS CoV-2. Virus replication weakens the immune system of host thereby altering T-cell count and much of interferon response. Although no vaccine or therapeutic treatment has been approved till now for CoV infection, trials of vaccine against SARS CoV-2 are in progress. One of the epitopes used for vaccine production is of the spike protein on the surface of virus. The work focuses on designing of multi-epitope vaccine construct for treatment of seven human CoV infections using the epitopes present on the spike protein of human CoVs. To address this, immuno-informatics techniques have been employed to design multi-epitope vaccine construct. B- and T-cell epitopes of the spike proteins have been predicted and designed into a multi-epitope vaccine construct. The tertiary structure of the vaccine construct along with the adjuvant has been modelled and the physiochemical properties have been predicted. The multi-epitope vaccine construct has antigenic and non-allergenic property. After validation, refinement and disulphide engineering of the vaccine construct, molecular docking with toll-like receptors (TLRs) have been performed. Molecular dynamics simulation in aqueous environment predicted that the vaccine-TLRs complexes were stable. The vaccine construct is predicted to be able to trigger primary immune response in silico. Communicated by Ramaswamy H. Sarma.