MORGANTOWN, W.Va. — The West Virginia University School of Medicine is researching ways to use a benign virus to create new treatments for eye diseases.
With the use of an engineered adeno-associated virus (AAV) the researchers hope to “compensate for missing protein or swap out genetic mutations that cause vision problems and replace them with DNA that works as it should.”
“Eighty-five percent of Americans are seropositive for AAV. However, the virus has never been associated with any pathological effect,” said Wen Tao Deng—an assistant professor in the Department of Ophthalmology and Visual Sciences—who is leading the effort. “We engineered the virus to use it as a vehicle to deliver the genes we are interested in. We use it as a tool to actually benefit us. So, this is a good virus.”
The five-year project, which focuses on genetic mutations that affect specific L and M-cone photoreceptors in the eyes, has been awarded $1.9 million by the National Eye Institute.
“When you lose your L and M-cones, basically you lose visual acuity; you lose your ability to read; you lose your color vision,” Deng said. “It severely, severely affects your daily function.”
The research involves the use of mice that have been genetically modified to lose their L- and M-cones similarly to how humans who inherit this mutation lose theirs.
The AAV’s can either replace a photoreceptor’s missing protein or “rout a troublesome mutation while installing healthy DNA in its place” inside the nucleus of a photoreceptor.
Deng hopes to develop new treatments that can impede a range of eye diseases caused by cone dystrophy.
“We are also interested in delaying the degeneration,” Deng said. “Some patients gradually lose vision. So, if you could delay their photoreceptor cell degeneration for 5 to 10 years, this also could give them an expanded window of treatment. This is especially important for children to buy time until we identify a treatment to reverse it.”