Japanese encephalitis virus (JEV) pathogenesis is driven by a combination of neuronal death and neuroinflammation. We tested 42 FDA-approved drugs that were shown to induce autophagy for antiviral effects. Four drugs were tested in the JE mouse model based on in vitro protective effects on neuronal cell death, inhibition of viral replication, and anti-inflammatory effects. The antipsychotic phenothiazines Methotrimeprazine (MTP) & Trifluoperazine showed a significant survival benefit with reduced virus titers in the brain, prevention of BBB breach, and inhibition of neuroinflammation. Both drugs were potent mTOR-independent autophagy flux inducers. MTP inhibited SERCA channel functioning, and induced an adaptive ER stress response in diverse cell types. Pharmacological rescue of ER stress blocked autophagy and antiviral effect. MTP did not alter translation of viral RNA, but exerted autophagy-dependent antiviral effect by inhibiting JEV replication complexes. Drug-induced autophagy resulted in reduced NLRP3 protein levels, and attenuation of inflammatory cytokine/chemokine release from infected microglial cells. Our study suggests that MTP exerts a combined antiviral and anti-inflammatory effect in JEV infection, and has therapeutic potential for JE treatment.
Synopsis: Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus with epidemic and sporadic occurrences. Its clinical presentation ranges from febrile illness to severe encephalitis and death, while survivors often show permanent neurological sequelae. Treatment is mostly supportive and there is an urgent need to develop effective antiviral therapy.Our previous studies suggested that autophagy upregulation could have a therapeutic advantage for JEV infection. Here, a panel of autophagy-inducing FDA drugs were tested for antiviral and anti-inflammatory effects.Oral administration of the phenothiazine antipsychotic drugs: Methotrimeprazine and Trifluoperazine showed reduced neuroinflammation and significant survival benefit in the JE mouse model.Methotrimeprazine showed strong antiviral and anti-inflammatory effect in diverse primary cell types. It dysregulated ER Ca2+ and induced a unique adaptive ER stress transcript signature.Drug induced adaptive ER stress was the key trigger for mTOR independent autophagy upregulation, which dually targeted virus replication complexes, and neuroinflammation.
Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus with epidemic and sporadic occurrences. Its clinical presentation ranges from febrile illness to severe encephalitis and death, while survivors often show permanent neurological sequelae. Treatment is mostly supportive and there is an urgent need to develop effective antiviral therapy.