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Researchers at the University of North Carolina at Chapel Hill haveshown that it is safe to cut and paste together different virusesin an effort to create the ultimate vehicle for gene therapy. In aphase I clinical trial, the investigators found no side effectsfrom using a "chimeric" virus to deliver replacement genes for anessential muscle protein in patients with muscular dystrophy . "This trial demonstrates that gene therapy is no longer limited bythe viruses we find in nature, and should usher in the nextgeneration of viral delivery systems for human gene transfer," saidsenior study author R. Jude Samulski, PhD, professor ofpharmacology and director of the Gene Therapy Center at UNC. Thestudy appeared online in the journal Molecular Therapy. Through gene therapy, scientists treat diseases by correcting apatient's faulty genes. Most of the time, this approach involvescommandeering a natural system for infecting and introducing newgenes into cells; thus, the virus. But even though there are lotsof relatively innocuous viruses available for this purpose, none ofthem are perfectly suited for gene therapy. Rather than rely on nature, Samulski and his colleagues decided toengineer their dream gene therapy virus in the laboratory. Firstthey chose the adeno-associated virus or AAV, a small nonpathogenicvirus that most humans are exposed to at some point in life. Theythen took their favorite attributes from different forms of AAV -such as AAV type 1's ability to sneak into muscle, and AAV type 2'ssafe track record - and combined them into one "chimeric" virus. Inthe first trial of this form of gene therapy, the investigatorsgave six boys with Duchenne muscular dystrophy (DMD) this newvirus. An x-linked inherited disorder, DMD affects one in 4,000newborn boys. The virus was engineered to contain the dystrophin gene, which ismissing in patients with muscular dystrophy and is the ultimatecause of the disease's progressive muscle weakness. The replacementgenes were injected into the bicep in one arm and a placebo wasinjected into the other arm of each of the patients. Theresearchers were able to detect the new genes in all of thepatients treated with the gene therapy, but no immunologicalresponse. As they move on to the next phase of clinical trials, Samulski saysthey are carefully considering how best to administer the genetherapy vectors to patients. Delivering enough replacement genes toa therapeutic effect could require larger doses of virus, which inturn could elicit an unwanted immune response. So the researchersare exploring a number of different options, including using a newhigh pressure technique developed by William J. Powers, MD,professor and chair of neurology at UNC, reported last July in thesame journal, to get the virus into muscle at lower doses. Additional References Citations. The e-commerce company in China offers quality products such as Plastic Flower Bags , China Non Woven Drawstring Bags, and more. For more , please visit Non Woven Drawstring Bags today!
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