New Therapy Helps Treat West Nile Virus

A novel RNA therapy has been developed that targets West Nile virus and helps prevent the progression of the disease, reveals a new study.

The innovative approach reduced the virus in the brain, allowing the immune system to destroy the virus and develop long-term protection against West Nile Virus disease, the researchers said.

‘Use of RNA therapy helps reduce the virus in the brain and can treat West Nile Virus disease.’

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A Yale-led research team published the findings in Cell Host & Microbe, may represent a breakthrough strategy for treating West Nile Virus after virus invasion of the brain and the central nervous system, noted senior author Priti Kumar, M.D., associate professor of infectious disease at Yale School of Medicine.

There are no approved vaccines or effective therapies for West Nile Virus disease, a mosquito-borne condition. While many infected individuals have no symptoms, others particularly the very young and older adults can develop severe neurological problems and even die from the disease.

The sporadic nature of the disease makes it exceedingly difficult for testing and implementing vaccines, said Kumar.

West Nile Virus - Symptoms Diagnosis Treatment Prevention
West Nile virus is an infection causing agent transmitted by mosquitoes. Most of the infected people do not display any signs or symptoms.

To investigate a possible new therapy to treat West Nile Virus disease, Kumar and her colleagues focused on a small "interfering" RNA molecule developed in her lab. The RNA acts against multiple mosquito-borne flaviviruses.

To direct the RNA to infected cells, they packaged it in a peptide derived from the rabies virus, which is able to enter nerve cells. The final step was to the deliver the therapy through the nose where it could bypass natural barriers protecting the brain.

New Antiviral Compound may Help Protect Brain From Deadly West Nile Virus
The compound does not attack the virus directly but prevents the invasion of virus into the brain by tightening the blood-brain barrier.

With this novel approach, the researchers found that the therapy reduced the virus in the brain, preventing harm to nerve cells.

The treated mice had a 90% survival rate a few days after infection compared to mice treated with placebo.

West Nile Virus may cause Fetal Brain Damage and Death
Viruses related to Zika like the West Nile virus and Powassan virus can affect the pregnant mother, which can be passed on to the fetus causing fetal brain damage.

Significantly, noted the researchers, in the surviving mice, the immune system cleared the virus throughout the body, and also enabled long-term protection against future exposure.

The researchers concluded that the treatment offers both a promising late-stage therapy and lifelong immunity. It "prevents pathology in the brain and gives the mice a chance to develop a robust immune response," said Kumar.

While the anatomy of the murine nose differs from that of humans, the researchers plan to study the therapy further with the hope it will be broadly applicable. "In translation, it should be an effective strategy for people," she said.

If that is the case, the intranasal RNA therapy could theoretically be developed for treatment of other mosquito-borne diseases, such as St. Louis encephalitis, Japanese encephalitis, and perhaps Zika, the researchers noted.

Source-Eurekalert