CHAPEL HILL, N.C. Researchers at the University of North Carolina at Chapel Hill have shown that it is safe to cut and paste together different viruses in an effort to create the ultimate vehicle for gene therapy. In a phase I clinical trial, the investigators found no side effects from using a "chimeric" virus to deliver replacement genes for an essential muscle protein in patients with muscular dystrophy.
"This trial demonstrates that gene therapy is no longer limited by the viruses we find in nature, and should usher in the next generation of viral delivery systems for human gene transfer," said senior study author R. Jude Samulski, PhD, professor of pharmacology and director of the Gene Therapy Center at UNC. The study appears online in the Nov. 8, 2011 issue of the journal Molecular Therapy.
Through gene therapy, scientists treat diseases by correcting a patient's faulty genes. Most of the time, this approach involves commandeering a natural system for infecting and introducing new genes into cells; thus, the virus. But even though there are lots of relatively innocuous viruses available for this purpose, none of them are perfectly suited for gene therapy.
Rather than rely on nature, Samulski and his colleagues decided to engineer their dream gene therapy virus in the laboratory. First they chose the adeno-associated virus or AAV, a small nonpathogenic virus that most humans are exposed to at some point in life. They then took their favorite attributes from different forms of AAV such as AAV type 1's ability to sneak into muscle, and AAV type 2's safe track record and combined them into one "chimeric" virus. In the first trial of this form of gene therapy, the investigators gave six boys with Duchenne muscular dystrophy (DMD) this new virus. An x-linked inherited disorder, DMD affects one in 4,000 newborn boys.
The virus was engineered to contain the dystrophin gene, which is missing in patients with musc
|Contact: Les Lang|
University of North Carolina School of Medicine