EpidemicsInfectious diseases: “Deleting” diseases from human bodies
Gene editing is revolutionizing the bioscience research landscape and holds great promise for “deleting” diseases from human bodies. Sandia National Laboratories is working to make this technology safer and to ensure that one day it can be delivered into humans without triggering adverse immune system reactions or causing other undesirable side effects.
Gene editing is revolutionizing the bioscience research landscape and holds great promise for “deleting” diseases from human bodies. Sandia National Laboratories is working to make this technology safer and to ensure that one day it can be delivered into humans without triggering adverse immune system reactions or causing other undesirable side effects.
Sandia biochemist Joe Schoeniger explains that gene editing technology is based on a “billion-year-old arms race” between bacteria and the viruses trying to attack them.
Bacteria save bits of invading viral DNA using a system called Clustered Regularly Interspaced Short Palindromic Repeats or CRISPR. This system helps bacteria recognize a virus when it returns for a repeat attack. The CRISPR system produces Cas9, an enzyme that binds to the offending viral DNA, then cuts and destroys it.
This bacterial defense system can be programmed. Scientists can send CRISPR-Cas9 to a precise location to alter a specific bit of DNA.
The ability to alter DNA is useful, especially when dealing with genetic diseases, but alterations to DNA are currently irreversible. Using the technology as it is today could cause unintended, dangerous and permanent side effects. It could cut a genome in the wrong place (that is, have off-target effects), potentially causing disease.
In addition, CRISPR-Cas9 needs a carrier to be delivered into human cells. Typically, this carrier is a virus linked to the common cold called adeno associated virus. Sandia Lab says that according to Sandia virologist Oscar Negrete, a majority of people have been exposed to strains of this virus at some point. This means people are quick to manufacture antibodies against it, making it a one-time use only therapy. Even on that first use, patients are likely to have an immune reaction, Negrete explained. New approaches are needed that enable the treatment to be successfully used more than once if necessary.
Controlling CRISPR
To be able to control CRISPR technology and use it without causing permanent DNA changes, the Defense Advanced Research Projects Agency created the Safe Genes program.
