Cell-based viral helicase assay for dengue drug discovery

SUMMARY The dengue virusDENVis a mosquito borne RNA virus that is responsible for overmillion infections a yearWhile dengue fever is mostly self limitingsevere dengue diseases are the leading causes of hospitalization and death in children living in limited resource areasCurrentlythere are no antiviral treatments for dengue diseases and existing vaccines have questionable safety profilesDue to its global prevalence and economic burdenthe discovery of anti dengue therapeutics is an urgent health priorityThe DENV virus encodes nonstructuralNSan enzymatic protein with helicase activityMutations in NS andapos s helicase active site prevents viral RNA synthesis initiation and render the virus replication incompetentFurtheramino acid residues responsible for NS andapos s helicase activity are conserved across the DENV serotypesThusNSis thought to be an attractive target for dengue drug discoveryHoweverhits identified from biochemical screens suffer from poor in vivo pharmacokinetics issues while hits identified from phenotypic screens are often non specificThereforea HTS assay that can specifically target NShelicase activity and be performed in cell based formats would enable the identification of more pharmacoactive hitsThis Phase I SBIR application aims to develop a genetically encodable fluorescent sensor that can report small molecule modulations of helicase activities and a proof of concept cell based assay that can identify small molecules that inhibit NShelicase activity in vivoWe believe the eventual cell based HTS platform would be a highly valuable tool in dengue drug discovery PROJECT NARRATIVE Dengue fever is one of the most prevalent infectious disease in the world and children have high risks of developing severe dengue diseasesCurrent dengue drug discovery tools are either targetor phenotypic basedand both approaches suffer limitations that result in poor hit identificationWe aim to develop a genetically encodable helicase sensor that enables target based drug screening approach in dengue host cell lines