Sequential changes in serum cytokines and chemokines in a rat model of Japanese encephalitis

The mechanisms underlying inflammation and immune responses in viral encephalitis are not fully understood. Therefore, in the present study we aimed to investigate the cytokine and chemokine levels in Japanese encephalitis virus (JEV)-infected rats.

Twelve-day-old Wistar rats were infected with 3 x 10(6) plaque-forming units of JEV intracerebrally. Cytokine and chemokine levels were analyzed in serum 3, 6, 10 and 20 days post inoculation (dpi).

There were increased levels of proinflammatory and anti-inflammatory cytokines and a chemokine (monocyte chemoattractant protein-1) in the serum of rats after JEV infection compared to controls. The levels of cytokines and chemokine peaked at 10 dpi and had declined significantly by 20 dpi. The neurological deficit also increased in the acute stage of disease and partially recovered thereafter.

Serum cytokine and chemokine levels decline at 10 dpi and do not significantly correlate with neurological dysfunction.