The gene-editing technology CRISPR has the potential to change everything about medicine. With CRISPR, scientists and doctors can potentially edit a person’s genome on the fly, fi all manner of genetic diseases with a simple, non-invasive procedure.
At least, that’s the plan. In reality, CRISPR is pretty complicated, and any attempt to use it in human patients inevitably leads to some complex engineering. A recent paper from a group of Stanford researchers even found that .
The findings were , which means it hasn’t been peer reviewed or published in a journal yet. Nevertheless, the paper has received a significant amount of attention from experts in genetics.
Part of the CRISPR system comes from bacteria, which often use it as a defensive weapon to attack viruses and other bacteria. CRISPR was discovered in 2012 and modified to deliver custom DNA to human cells, but at its core it’s still something that came from bacteria. That means that our immune systems have probably evolved to fight it.
At the center of the issue is a protein called Cas9, which is used as part of CRISPR-Cas9 to target and cut out specific sections of DNA. Without Cas9, CRISPR wouldn’t work, but it’s this specific protein that our bodies have learned to fight. Cas9 is typically found in harmful bacteria like Staphylococcus aureus and Streptococcus pyogenes, which cause staph and strep infections, respectively, so it’s usually a good thing that our bodies fight the protein.
However, this does present a hurdle for researchers learning how to use CRISPR in human trials. There are already some tricks that researchers are using to circumvent our immune systems, like only using CRISPR outside of the body or in places that immune cells can’t reach, but ultimately we may have to abandon Cas9 for a different protein that doesn’t set off our bodies’ defenses. And if that’s the case, CRISPR researchers could be facing a serious setback.