Scientists discover the gene editing ‘off-switch’ that could protect against accidents or stop it from being used for harm

Home / Immunology / Scientists discover the gene editing ‘off-switch’ that could protect against accidents or stop it from being used for harm
January 04, 2017January 4, 2017
0

 

  • Researchers found proteins that are ‘potent inhibitors’ against Crispr-Cas9
  • Anti-Crispr proteins make procedure more precise to prevent an accident
  • And, it would also provide a ‘fail safe’ if the technology falls in the wrong hands

In recent years, the use of gene editing techniques has raised concern among both scientists and the public, with some fearing it could lead to unintended consequences, or even be used to create biological weapons.

Now, researchers have discovered a set of proteins that could act as a kill switch for the Crispr-Cas9 system, potentially blocking both of these outcomes.

Not only would the anti-Crispr proteins make the procedure more precise to prevent an accident from spilling out of control, but the scientists say it would also provide a ‘fail safe’ if the technology falls in the wrong hands.

Not only would the anti-Crispr proteins make the procedure more precise to prevent an accident from spilling out of control, but the scientists say it would also provide a ‘fail safe’ if the technology falls in the wrong hands. A stock image is pictured 

Not only would the anti-Crispr proteins make the procedure more precise to prevent an accident from spilling out of control, but the scientists say it would also provide a ‘fail safe’ if the technology falls in the wrong hands. A stock image is pictured

ABOUT CRISPR-CAS9

CRISPR-Cas9 is a tool for making precise edits in DNA, discovered in bacteria. The acronym stands for ‘Clustered Regularly Inter-Spaced Palindromic Repeats’.

The technique involves a DNA cutting enzyme and a small tag which tells the enzyme where to cut. By editing this tag, scientists are able to target the enzyme to specific regions of DNA and make precise cuts, wherever they like.

It has been used to ‘silence’ genes – effectively switching them off.

When cellular machinery repairs the DNA break, it removes a small snip of DNA. In this way, researchers can precisely turn off specific genes in the genome.

The approach has been used previously to edit the gene called HBB responsible for a condition called β-thalassaemia.

Researchers at the University of California, San Francisco say the ‘off-switch’ would work on the widely used Crispr-Cas9 gene editing system.

Among the many possible applications, it’s hoped that the Crispr-Cas9 system could be used to treat genetic disorders.

It relies on a protein called SpyCas9 as its target DNA ‘clippers’, and to find the off-switch, the researcher investigated the same process that gave rise Crispr-Cas9 itself.

‘Just as Crispr technology was developed from the natural anti-viral defense systems in bacteria, we can also take advantage of the anti-Crispr proteins that viruses have sculpted to get around those bacterial defenses,’ said Benjamin Rauch, PhD, a post-doctoral researcher in the laboratory of Joseph Bondy-Denomy, PhD, and a UCSF Sandler Faculty Fellow in the Department of Microbiology and Immunology.

The researchers looked for evidence of ‘self-targeting’ – bacterial strains where some virus had infiltrated the Cas9 blockade and inserted its own genes into the bacterial genome.

They hypothesized that they must encode an ‘anti-Crispr agent.’

If not, the researchers explained, the Cas9 would cut its own genome where the invader was detected in order to kill off the virus.