The ability to create genetically-modified super humans has been not only a recurring theme of science fiction tales, but also a dream of military brass and less-than-peaceful world leaders throughout history. Unfortunately, that dream might soon be a reality thanks to the radical genetic breakthrough known as CRISPR-Cas9. This technique uses modified bacterial RNA to essentially ‘cut and paste’ certain sections of an organism’s genome in order to edit specific aspects of its genetic makeup. Chinese scientists recently conducted the first human trials of CRISPR technology in an attempt to alter a cancer patient’s immune system response, but the effectiveness of the trial is still unknown.
Many bioethicists and medical watchdog groups are worried about CRISPR-Cas9 applications, fearing they could lead to unknown changes in the human genome in subsequent generations or that CRISPR segments could go “rogue” once applied to a patient’s DNA. To allay those fears, scientists at the University of California San Francisco have announced the successful creation of a CRISPR-Cas9 “off switch.”
The CRISPR kill switch comes in the form of specific proteins found in the deadly foodborne Listeria monocytogenes bacteria which have the ability to essentially shut down CRISPR RNA. According to new research published in the biomedical journal Cell, these newly discovered anti-CRISPR proteins (AcrIIAs) can effectively stop the gene-editing of CRISPR-Cas9 in its tracks:
The ability of AcrIIA proteins to block Spy Cas9 in E. coli and human cells suggests that these proteins can provide a post-translational ‘‘off-switch’’ for Cas9. This could add a layer of regulation on this powerful system that can be applied in eukaryotic systems to control genome engineering.
Already, some outlets are hailing this as the discovery which will make human genome editing “safe” for everyday use. However, others are speculating that CRISPR technologies are a dangerous development which could lead to a new genetic arms race (gene race?) in which nations pit their genetically-altered superhuman soldiers against one another.
Worryingly, the researchers behind the CRISPR kill switch seem to have hinted to this potential militaristic application of CRISPR in the conclusion of their recent publication:
It will be important to continue to exploit the abundant tools provided to us from the phage-bacteria arms race as we expand the CRISPR-Cas toolbox.
Just what the world needs: another arms race.