Development of a Porcine Cell Line Stably Expressing Ephrin-B2 for Nipah Virus Research and Diagnostic Testing

Nipah virus (NiV) is a highly pathogenic zoonotic virus transmitted from bats to humans through pigs as a crucial intermediate host. NiV outbreaks pose significant public health and economic threats, especially for pig farmers. Although the World Organization for Animal Health recommends African green monkey-derived Vero cells for NiV isolation, pig-derived cell lines could represent an optimal platform for propagating pig-origin NiV, as signs and symptoms of NiV infection differ among different hosts. In this study, we generated and evaluated pig-derived PK-15 cells stably expressing pig-derived ephrin-B2 (PK-15/Ephrin-B2 cells), the primary receptor for NiV. NiV pseudovirus infectivity was increased by > 1000-fold in PK-15/Ephrin-B2 cells compared with that in wild-type PK-15 cells, whereas virus susceptibility was higher in PK-15/Ephrin-B2 cells than in Vero cells (> 30-fold). Furthermore, Stat2-knockout PK-15/Ephrin-B2 cells exhibited stable viral infectivity in the presence of type I interferon, making it particularly suitable for clinical sample testing. Moreover, PK-15/Ephrin-B2 cells proved useful for neutralization tests using anti-NiV hyperimmune ascitic fluid. Therefore, PK-15 cells expressing pig ephrin-B2 could represent an efficient tool for virus isolation, vaccine development, and virological studies of NiV and related henipaviruses.