Heat shock protein 90β in the Vero cell membrane binds Japanese encephalitis virus

The pathogenesis of Japanese encephalitis virus (JEV) is complex and unclearly defined, and in particular, the effects of the JEV receptor (JEVR) on diverse susceptible cells are elusive. In contrast to previous studies investigating JEVR in rodent or mosquito cells, in this study, we used primate Vero cells instead. We noted that few novel proteins co-immunoprecipitated with JEV, and discovered that one of these was heat shock protein 90β (HSP90β), which was probed by mass spectrometry with the highest score of 60.3 after questing the monkey and human protein databases. The specific HSP90β-JEV binding was confirmed by western blot analysis under non-reducing conditions, and this was significantly inhibited by an anti-human HSP90β monoclonal antibody in a dose-dependent manner, as shown by immunofluorescence assay and flow cytometry. In addition, the results of confocal laser scanning microscopic examination demonstrated that the HSP90β-JEV binding occurred on the Vero cell surface. Finally, JEV progeny yields determined by plaque assay were also markedly decreased in siRNA-treated Vero cells, particularly at 24 and 36 h post-infection. Thus, our data indicate that HSP90β is a binding receptor for JEV in Vero cells.