Development of multi-epitope driven subunit vaccine against Fasciola gigantica using immunoinformatics approach.

Fascioliasis, a serious helminth disease of the livestock population, results from infection with the parasite Fasciola. Despite the alarming increase in drug resistance, a safe and fully effective vaccine for fascioliasis is still not available. In the present study, we employed high-throughput immunoinformatics approaches to design a multi-epitope based subunit vaccine using seven important F. gigantica proteins (cathepsin B, cathepsin L, leucyl aminopeptidase, thioredoxin glutathione reductase, fatty acid binding protein-1, saposin-like protein-2, and 14-3-3 protein epsilon). The CTL, HTL, and B-cell epitopes were selected for designing the vaccine on the basis of their immunogenic behavior and binding affinity. The engineered vaccine showed potential immunogenic efficacy by elaborating the IFN-γ and humoral response. The modeled structure of the vaccine was docked with the toll-like receptor-2 immune receptor, and the molecular dynamics simulation was performed to understand the stability, interaction, and dynamics of the complex. Finally, in silico cloning of the resulting vaccine was performed to create the plasmid construct of vaccine for expression in an appropriate biological system. Experimental evaluation of the designed vaccine construct in an animal model may result in a novel and immunogenic vaccine that may confer protection against F. gigantica infection.