Biologists have hijacked a virus to nix its harmful properties and harness its ability to enter the brain through the bloodstream. At least in mice, the virus can deliver genes to certain cells in the nervous system by bypassing the blood-brain barrier that often trips therapies up. Here’s what lead researchers Ben Deverman and Viviana Gradinaru of Caltech said about the findings, published in Nature Biotechnology.
What’s the problem with current gene delivery into the brain?
Usually gene delivery is done by invasive local injections. You take a needle, make a hole in the skull, and inject a few milliliters of a vesicle that delivers the gene. So you have a lot of copies of your delivery target locally at that injection site, but it dies down as the gene moves further from the injection site. If you want to deliver genes for research or therapy purposes, you want uniformity.
What did you do to push for that uniformity?
Our method is delivering it to the [network of blood vessels] since the vasculature touches nearly every cell in the brain. We took a virus that was known to cross the blood-brain barrier very efficiently and we evolved a variant of that. What makes these viruses attractive as gene delivery vehicles…is that we can strip them of all the viral genes.
What are the limitations of that finding?
Although these viruses have been used in research, they’re not very well characterized. We don’t understand the mechanism for how it crosses the blood-brain barrier. This method also takes very high doses of viruses, so we’re trying to make it more efficient.