In silico Analysis of a Chimeric Protein as a Potential Diva Vaccine Candidate for Bluetongue Disease

Bluetongue virus (BTV), transmitted by Culicoides biting midges, poses significant threat to the health of sheep and goats, causing bluetongue (BT) disease and substantial economic loss in the small ruminant sector. Current control strategies using a pentavalent inactivated vaccine have certain limitations, emphasising the urgent need for more effective and broadly protective vaccines. The outer surface proteins of BTV, VP2 and VP5, appear to be promising targets for a subunit vaccine for BT. The present study aimed to investigate the immunogenic potential of a chimera comprising a conserved region of VP2 (cVP2) and VP5 proteins for BT, which can ultimately offer cross-protection against the majority of known BTV serotypes. Both cVP2-VP5 were stitched together with the help of different linkers, leading to the formation of a chimeric protein. An immuno-informatics approach was employed to assess the antigenicity and the presence of B-cell and T-cell epitopes in the constructed chimeric proteins. The 3D structure was predicted, refined and validated using bioinformatic tools. Of the 12 linkers tested, chimeras with four linkers expressed the maximum number of immunogenic epitopes on the surface, emphasising the critical role of linkers in maintaining conformational flexibility and preventing steric hindrance, thereby enabling proper folding and presentation of epitopes. The present study employs an immuno-informatic-driven approach to develop a probable subunit vaccine with potential DIVA (differentiation between infected and vaccinated animal) ability for BT.