Tyrosine kinase inhibitors attenuate Japanese encephalitis virus-induced neurotoxicity.

The cellular signaling molecules that underlie Japanese encephalitis virus (JEV)-induced inflammation and neurotoxicity are not well understood. We examined whether protein tyrosine kinase (PTK) inhibitors play roles in JEV replication and cytopathic effect in neuron/glia cultures. JEV infection caused significant neuronal injury. PTK inhibitors, genistein, herbimycin A, and PP2, attenuated JEV-induced neurotoxicity but failed to affect JEV replication. Infection of neuron/glia cultures with JEV produced elevated levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta). PTK inhibitors suppressed JEV-induced TNF-alpha and IL-1beta production at the transcriptional level. Neutralizing antibodies against TNF-alpha and IL-1beta partially suppressed JEV-induced neurotoxicity. JEV infection modulated tyrosine phosphorylation events within the course of infection. Currently, the nature of the affected phosphorylated proteins was not characterized. Our results suggest that PTKs, especially Src-related PTK, play roles in the production of TNF-alpha and IL-1beta during JEV infection and in the induction of neuronal death in neuron/glia cultures.