Japanese encephalitis virus-infected macrophages induce neuronal death.

Inflammation in the central nervous system (CNS) in Japanese encephalitis (JE) is shown to be the result of microglial activation that leads to the release of various proinflammatory mediators. Peripheral macrophages have been reported to infiltrate into the CNS in JE, though their contribution to the inflammatory process is yet to be elucidated. In this study, using an in vitro macrophage model, we have shown that upon JE virus infection, these cells secrete various soluble factors which may significantly add to the existing inflammatory milieu and lead to apoptotic or necrotic death of neurons. However, it is difficult to quantify the extent of involvement of either the microglia or infiltrating macrophages in the inflammatory processes.