The more scientists learn about how our genes build our bodies, the better they get at hacking this process. Right now, they're already adept enough to restore vision to blind mice.
Gene therapy is powerful new technique by which doctors may one day be able to use the body's own machinery to cure disease. In many cases, a disease boils down to a malfunctioning gene or set of genes, and could be fixed by inserting working genes to pick up the slack.
In the case of the blind mice, the vision cells in their eyes were destroyed. The eye contains two key types of vision cells: rods, which detect light intensity, and cones, which detect color. These cells enable sight because they contain special pigment molecules that react with light, and this reaction gets converted into a chemical signal that tells your brain what's going on.
So researchers packaged the gene for a light-detecting pigment called rhodopsin, found in functional rod cells, inside a virus. The DNA within that virus also contained specific genetic instructions that tell the gene that is can only switch on when it's inside particular cells in the eye. These cells are deeper within the eye than rods and cones and don't naturally sense light.
When they deployed the virus into the eyes of the mice, the rhodopsin got incorporated into those non-light-cells and turned them into surrogate rod cells. With this change, mice that were utterly blind before ran away in response to a video of an owl on the hunt.
"Our mice could respond in ordinary light, the equivalent of looking at a computer monitor under ordinary office lighting," said Rob Lucas, co-leader of the team of researchers at the University of Manchester that is developing the treatment, to New Scientist.
The rhodopsin gene that the researchers used was actually a human gene — which hints that the same method might work in people. Nevertheless, the researchers still have to conduct tests in humans to confirm this, and scientists also warn that they don't know how long the effects of this gene therapy will last.
Photo: Bodey Marcoccia | Flickr