doi:10.1038/nindia.2017.38 Published online 28 February 2017
Researchers have gained new insights into how the Japanese encephalitis virus (JEV) evades immune response and proliferates in the brain by using host’s RNA molecules1. They have shown that inhibiting the tiny molecules’ activity can stop the virus replicating.
Existing therapies for Japanese encephalitis only relieve the symptoms, but do not offer a cure. To provide therapy leads, biologists led by Anirban Basu from National Brain Research Centre, Haryana studied the immune responses of neuronal cells and mice brain to the viral infection.
They found that Japanese encephalitis virus triggered an abundance of tiny RNA molecules, miR-301a, in mice neuronal cells and reduced the levels of specific interferons, proteins that play vital roles in host’s antiviral defense.
When the activity of miR-301a was inhibited, levels of interferon increased considerably. This, in turn, affected viral replication, significantly reducing the abundances of viral genetic material in the mice brain cells. Treating JEV-infected mice with Morpholino, a molecule that inhibits the activity of miR-301a relieved clinical symptoms of Japanese encephalitis such as paralysis and weight loss.
“The results show that miR-301a might be a potential therapeutic target and anti-miR-301a therapy can be used to treat JEV infection in humans,” says lead author Bibhabasu Hazra from the NBRC, Haryana.
1. Hazra, B. et al. The host microRNA miR-301a blocks the IRF1-mediated neuronal innate immune response to Japanese encephalitis virus infection. Sci. Signal.10, eaaf5185 (2017)