How the immune system could stymie some CRISPR gene therapies

Researchers hoping to use a gene-editing technique to treat diseases may have to seek alternative enzymes.

The body’s own immune system could thwart some efforts to develop gene therapies based on the trendy genome-editing tool called CRISPR-Cas9, according to a study released on 5 January¹.

Hopes are high that CRISPR–Cas9 could one day be used in people to correct mutations that cause disease. But the new study, which was published on the preprint server bioRxiv and has not yet been peer-reviewed, is generating questions about whether this approach will succeed.

Nature looks at what the findings mean for the popular genome-editing system — and the academics and companies who hope to harness it to treat genetic diseases. 

How does CRISPR–Cas9 work?

CRISPR–Cas9 is a primitive immune system that is found in a wide range of microorganisms. The system relies on an enzyme called Cas9, which slices DNA at a site determined by the sequence of a particular strand of RNA. Researchers can alter the sequence of that ‘guide RNA’ to aim Cas9 at a specific segment of...