Screening human brain targets for Japanese encephalitis virus NS5 via yeast two-hybrid assay

Japanese encephalitis (JE) is the most important vaccine-preventable acute meningoencephalitis in tropical and subtropical Asia with no known antiviral therapeutics. Available vaccines offer limited protection against emerging Japanese encephalitis virus (JEV) genotypes, posing a persistent public health threat. Disruption of the interactions between JEV non-structural protein 5 (NS5) protein and human brain cellular proteins could be explored to develop flavivirus druggable host targets. This study aimed to identify the human brain cellular proteins that interact with the JEV NS5 protein. A highthroughput yeast two-hybrid (Y2H) screen of a normalized human brain cDNA library was carried out to identify human brain proteins that physically interacted with the JEV NS5 protein. Colony polymerase chain reaction (colony PCR), sequencing and BLAST analysis were carried out to identify and confirm the positive clones. Of the 32 selected large blue colonies on the double dropout media (DDO), only 20 (62.5%) survived on the more stringent selection media (QDO) and retained their blue coloration. Colony PCR, sequencing and BLAST analysis showed that these colonies on a more stringent media carried human brain cDNAs including one uncharacterized cDNA as potential interactors of JEV NS5. Gene Ontology (GO) enrichment analysis identified chemical carcinogenesis-reactive oxygen species, Parkinson's disease, and necroptosis as important biological pathways for JEV neuropathogenesis. The identified JEV NS5-interacting human brain cDNAs highlight the role of NS5 protein and biological pathways such as oxidative stress, Parkinson's disease and necroptosis in JEV neuropathogenesis. These pathways represent potential targets for neuropathologic flavivirus infection.