Robust immunogenic potential of N and C-terminal deleted variant of dengue virus NS1 protein (dNS1)

Abstract

NS1 is an elusive dengue protein which assists in viral replication, assembly, pathogenesis, and immune evasion. It is secreted in blood plasma, where its levels are positively related to disease severity. It interacts with immune receptors and endothelial cells and triggers the production of inflammatory cytokines leading to severe clinical implications like thrombocytopenia, hemorrhage, and vascular leakage. Despite its pathogenic roles, NS1 is being used in various vaccine formulations due to its sequence conservancy among flaviviruses, ability to produce protective antibodies, and low risk for inducing antibody-dependent enhancement. The pathogenic effects of NS1-based therapies can be overcome by introducing careful modifications in the NS1 protein. In this study, we have utilized ­bioinformatics tools and reported literature to remove the pathogenic sequences from NS1, and developed an NS1 variant (dNS1). Molecular docking studies are performed to compare the receptor-binding ability of the NS1 and dNS1 with TLR4. The comparative analysis of immunogenic potential between NS1 and dNS1 by ELISA and western blotting have revealed that antibody titers of dNS1 in rabbits are three times greater than that of NS1. The results of this study endorse the use of dNS1 as a substitute for NS1 in future vaccine formulations to achieve a safer and more effective dengue therapy.