Researchers at the University of Florida have developed a new gene therapy to treat retinitis pigmentosa (RP), according to a study in the January 23 online edition of the Proceedings of the National Academy of Sciences. The therapy is applied by replacing a malfunctioning gene in the eye with a normal copy that supplies the protein necessary for proper photoreceptor function.
William W. Hauswirth, Ph.D., and Alfred S. Lewin, Ph.D., have successfully treated retinitis pigmentosa in dogs.
“Providing the gene that’s missing is one of the ultimate ways of treating the disease and restoring significant visual function,” said study coauthor William W. Hauswirth, Ph.D., professor of ophthalmology at the UF College of Medicine and professor of molecular genetics and microbiology at the UF Genetics Institute.
In laboratory testing, the researchers cloned a working copy of the affected gene into a virus that served as a delivery vehicle. They also included a specialized “switch” that would activate the gene once it reached the proper location. After activation, the gene produced a protein that allowed the damaged retinal cells to function normally.
Following laboratory testing, the researchers used the gene delivery vehicle to successfully treat X-linked RP in dogs.
“The results are encouraging and the rescue of the damaged photoreceptor cells is quite convincing,” said John G. Flannery, Ph.D., professor of neurobiology at the University of California, Berkeley, and an expert on the delivery of replacement genes. “Since this type of study is often the step before applying a treatment to human patients, showing that it works is critical.”
Beltran WA, Cideciyan AV, Lewin AS, et al. Gene therapy rescues photoreceptor blindness in dogs and paves the way for treating human X-linked retinitis pigmentosa. PNAS. 2012 Jan 23. [E-pub ahead of print]
