So in order to test just how wide and efficiently AAV8 could deliver a new gene, he filled the virus with a gene that makes cells glow in the dark. After a single injection into the bloodstream of hamsters, virtually every muscle cell lit up from the new gene.
|As time went on, the gene was expressed in virtually every muscle cell of hamsters.|
image: Xiao Xiao
"The entire animal now will shed green light, so the gene is basically expressed in every muscle cell," Xiao says. "We are surprised, because we did not expect such a high efficiency."
It's that kind of efficiency that frightens sporting officials wary of a future riddled with athletic "gene doping." Xiao is aware of that concern, but says that shouldn't stop him.
"We cannot be deterred just because of that concern and stop the development of gene therapy approaches for genetic disease and life threatening disease," he says.
He also points out that there's a long way to go to prove that AAV8 is safe. In fact, he found that the fluorescent gene was delivered to places one might not want it— like the liver and pancreas.
For now Xiao encourages regulations that keep gene therapy in the arena of medicine, and off the field of play. His next study will use AAV8 to try to deliver a gene that fixes damaged muscles in hamsters with a form of muscular dystrophy.
Xiao's study was published in Nature Biotechnology's advance online edition on February 27, 2005. The work was funded by the National Institutes of Health.