Researchers resurrect extinct virus to use for gene therapy

Modern molecular biology holds the promise of allowing us to correct genetic diseases. Experiments with gene therapy indicate that it should be possible to provide a functional version of a gene to cells that have a defective copy.

The challenge here is that it requires inserting the DNA of the gene into a large number of cells in a living organism. Viruses are highly (and unfortunately) efficient at inserting their own genes into human cells, and many gene therapy tests have used modified viruses. But the human immune system can respond to these modified viruses, neutralizing the therapy. Now, researchers have created a gene therapy virus that nobody's immune system has ever seen—because it's been extinct for many years.

There are a lot of viruses that have been suggested as possible gene therapy tools, but all of them have some drawbacks. Some viruses only infect a few specific cell types; others insert DNA randomly in the genome, creating a risk of mutations.