Investigation into the relationship between Japanese encephalitis virus and microglial cells

Abstract

Japanese encephalitis virus (JEV), a mosquito-borne virus that belongs to the family Flaviviridae, is a major cause of viral encephalitis in Asia. Even though the principle target cells for JEV in the central nervous system are neurons, the microglial cells are also activated in response to JEV infection. This study aimed to investigate the involvement of microglial cell upon JEV infection. Using mouse microglial (BV-2) cell line as a model, the JEV virions were detected in the cytoplasm of BV-2 cells by immunocytochemistry indicating cellular permissiveness to the virus. The extracellular virions were released into the culture medium, determined by standard plaque assay, implying one complete viral cycle at 10 hr post infection. It was proved possible to culture the persistent JEV-infected BV-2 cells for 16 weeks with a viral titer of 105 p.f.u./ml. For the identification of JEV binding protein(s) on the surface of BV-2 cells, one dimensional and two dimensional virus overlay protein binding assay, followed by tandem mass spectrometry (LC/MS/MS) were applied. A JEV binding protein band of 43 kDa laminin receptor precursor protein was identified. The newly identified JEV binding protein is a potential candidate JEV receptor protein on microglial cells.