Scientists refine a gene editing tool

Scientists at the Wake Forest Institute of Regenerative Medicine have tweaked their administration system to provide a DNA editing tool to modify DNA sequences and to change the function of genes. The improved "hit and run" system works faster and is more efficient.

"With this new method, we are able to bundle in a lentiviral capsid the two essential components (Cas9 protein and guide RNA) for CRISPR-mediated gene editing," said Baisong Lu, Ph.D., Assistant Professor of Regenerative Medicine at the WFIRM, and another. of the main authors of the document. "Previously, both components had to be delivered separately, which was not so convenient."

CRISPR technology (clustered regularly spaced short palindromic repeats) is used to modify DNA sequences and modify gene function. CRISPR / Cas9 is an enzyme used as a pair of scissors to cut two strands of DNA at a specific location to add, delete or repair DNA fragments. But CRISPR / Cas9 is not 100% accurate and could potentially cut unexpected locations, resulting in unwanted results.

Now, the WFIRM team can package the two components – the Cas9 protein (the enzyme) and the RNA guide – as ribonucleoproteins inside the lentiviral capsid, thus creating a lentiviral capsid-based bionanoparticle system for administering CRISPR / Cas9. The lentiviral vector is a gene transmission vehicle widely used in research laboratories and is already widely used to administer the CRISPR / Cas9 mechanism for efficient genome editing. However, the use of the lentiviral vector to deliver CRISPR / Cas9 will result in the long-term expression of the endonuclease, which is undesirable for safety reasons. The new system offers the efficiency of administration of conventional lentiviral vectors, but allows the transient expression of Cas9. Thus, the new CRISPR / Cas9 distribution system is more efficient and safer.

The research led the team to hypothesize that a "similar strategy should be able to be translated into other publisher proteins for gene disruption," he said. Anthony Atala, MD, director of WFIRM and co-author of the paper. "We may be able to use this to pack and deliver other RNPs into mammalian cells, which was difficult to obtain until now."

The research is part of an ongoing effort to improve the efficiency of gene editing in vivo, which will be useful in research and clinical applications by improving safety and avoiding responses. possible immune system.

The WFIRM team published its findings in the journal Nucleic acid research.