“Due to its size, it is impossible to deliver the entire gene with a gene therapy vector, which is the vehicle that carries the therapeutic gene to the correct site in the body,” Duan said. “Through previous research, we were able to develop a miniature version of this gene called a microgene. This minimized dystrophin protected all muscles in the body of diseased mice.”
However, it took the team more than 10 years to develop a strategy that can safely send the micro-dystrophin to every muscle in a dog that is afflicted by the disease. The dog has a body size similar to that of an affected boy. Success in the dog will set the foundation for human tests.
In this latest study, the MU team demonstrated for the first time that a common virus can deliver the microgene to all muscles in the body of a diseased dog. The dogs were injected with the virus when they were two to three months old and just starting to show signs of DMD. The dogs are now six to seven months old and continue to develop normally.
Gene therapy continues to disappoint. It was hyped in the 1990s and yet failed over safety issues. A couple of decades later its use is still rare. My guess is that cell therapies will grow faster than gene therapies. Gene therapy done on cells outside of the body might take off sooner. Cells outside the body could be genetically edited with CRISPER-Cas9 and then the altered cells could be injected. Once it becomes possible to grown organs outside of the body then gene therapy could be used to prepare cells to grow a new organ.
Since we all have hundreds of mildly harmful mutations the ability to do genetic editing has a lot of potential. Imagine getting all your genetic flaws fixed in a cell line and then getting new organs grown to replace aged and poorly performing organs. If will happen in the lifetimes of some people alive today. But it is not clear how many of us will still be around to benefit when it finally arrives.
|Share |||Randall Parker, 2015 October 31 06:49 PM|