Generation of rescued Japanese encephalitis virus genotype 1 from infectious full-size clone using reverse genetics

Abstract

Japanese encephalitis virus (JEV) is a pathogen responsible for high mortality and morbidity rates among children with encephalitis. Since JEV genotype 1 (GI) is the most prevalent strain in South Korea these days, corresponding research and vaccine development is urgently required. Molecular genetic studies on JEV vaccines can be boosted by obtaining genetically stable full-length infectious JEV complementary DNA (cDNA) clones. Furthermore, the significance of the reverse genetics system in facilitating molecular biological analyses of JEV properties has been demonstrated. This study constructed a recombinant JEV-GI strain using a reverse genetics system based on a Korean wild-type GI isolate (K05GS). RNA extracted from JEV-GI was used to synthesize cDNA, a recombinant full-length JEV clone, pTRE-JEVGI, was generated from the DNA fragment, and the virus was rescued. We performed in vitro and in vivo experiments to analyze the rescued JEV-GI virus. The rescued JEV-GI exhibited similar characteristics to wild-type JEV. These results suggest that our reverse genetics system can generate full-length infectious clones that can be used to analyze molecular biological factors that influence viral properties and immunogenicity. Additionally, it may be useful as a heterologous gene expression vector and help develop new strains for JEV vaccines.