Novel 'GaEl antigenic patches' identified by 'reverse epitomics' approach to design multi-patch vaccines against NIPAH infection, a silent threat to global human health

BackgroundNipah virus (NiV) is a zoonotic virus that causes lethal encephalitis and respiratory disease with the symptom of endothelial cell-cell fusion. Several NiV outbreaks have been reported since 1999 with nearly annual occurrences in Bangladesh. The outbreaks had high mortality rates ranging from 40 to 90%. No specific vaccine has yet been reported against NiV. MethodologyRecently, several vaccine candidates and different designs of vaccines composed of epitopes against NiV were proposed. Most of the vaccines target single protein or protein complex subunits of the pathogen. The Multi-epitope vaccines proposed also cover a largely limited number of epitopes and hence their efficiency is still pending. To address the urgent need for a specific and effective vaccine against NiV infection in the present study, we have utilized the Reverse Epitomics approach ("overlapping-epitope-clusters-to-patches" method) to identify antigenic patches (Ag-Patches) and utilize them as immunogenic composition for Multi-Patch vaccine (MPV) design. The designed MPVs were analyzed for immunologically crucial parameters, physiochemical properties and interaction with Toll-like receptor 3 ectodomain. ResultsIn total 30 CTL (Cytotoxic T lymphocyte) and 27 HTL (Helper T lymphocytes) antigenic patches were identified from the entire NiV proteome based on the clusters of overlapping epitopes. These identified Ag-Patches cover a total of discreet 362 CTL and 414 HTL epitopes from entire proteome of NiV. The antigenic patches were utilized as immunogenic composition for the design of two CTL and two HTL multi-patch vaccines. The 57 antigenic patches utilized here cover 776 overlapping epitopes targeting 52 different HLA class I and II alleles providing a global ethnically distributed human population coverage of 99.71%. Such large number of epitope coverage resulting in large human population coverage cannot be reached with single protein/subunit or multi-epitope based vaccines. The reported antigenic patches also provide potential immunogenic composition for early detection diagnostic kits for NiV infection. Further, all the MPVs & Toll-Like Receptor ectodomain complexes show stable nature of molecular interaction with numerous hydrogen bonds, salt bridges and non-bounded contacts formation and acceptable root mean square deviation and fluctuation. The cDNA analysis show a favorable large scale expression of the MPV constructs in human cell line. ConclusionBy utilizing the novel Reverse epitomics approach highly immunogenic novel GaEl antigenic patches (GaEl Ag-Patches) a synonym term for antigenic patches, were identified and utilized as immunogenic composition to design four MPVs against NiV. We conclude that the novel Multi-Patch Vaccines is a potential candidate to combat NiV, with greater effectiveness, high specificity and large human population coverage worldwide.