Two years later, Gene Editing Pioneer published several articles such as Cell: Leading editing efficiency increased by 10 times!

In 2019, Professor David R.

One year later, his research team issued a paper again and published further research results on the lead editor in Cell and Nature Biotechnology: They used Prime Editor to correct various neurodegenerative diseases, metabolism and cardiovascular diseases.

Prime Editor is a precise gene editing method, it is possible to correct most known disease-causing gene variants

In order to further develop this technology, scientists at MIT and Harvard's Broad Institute have improved a key component of the lead editing system, which is called prime editing guide RNAs (pegRNAs).

In this study in the journal Nature Biotechnology, researchers showed that pegRNAs can be degraded in cells, causing truncated pegRNAs to interfere with promoter editing

In the second study published today in the journal Cell, Broad researchers worked with scientists from Princeton University and the University of California, San Francisco to identify cellular pathways that limit editing efficiency and use these findings to develop a new generation of prime editing systems.

Researchers in both studies have demonstrated that the new system can more effectively edit mutations associated with Alzheimer’s disease, heart disease, sickle cell and prion disease, type 2 diabetes, and other diseases, while producing fewer mutations.

"These improved initial editing efficiency and product purity have brought many editors from a system that may be used as a research tool to a system that may be used as a treatment," Richard Merkin, director of the Broad Institute (Institute) Meijin Institute of Medical Reform Technology Say

Design a more stable guidance system

Lead editing allows scientists to correct most known disease-causing mutations, including substitutions, insertions, or deletions of dozens of base pairs

After describing this editing technique for the first time in 2019, Liu Ruqian's team continued to develop this technique

The researchers next looked for protective structures that could be added to pegRNA

Researchers used engineered pegRNA, or epegRNA, in a series of mammalian cell lines and found that epegRNA increased the efficiency of promoter editing by an average of three to four times, and made even greater improvements in cell lines where promoter editing is more difficult

Guide cell

In Cell's research, the team and their collaborators designed the protein components of the lead editing system to further improve efficiency and minimize by-products produced by multiple cell types, including patient cells

Researchers aim to have a more comprehensive understanding of the cytokines that determine the results of the lead editing in order to design more effective systems

To test this hypothesis, the researchers worked with Britt Adamson and Jonathan Weissman of Princeton University to systematically study the effect of lead editing to shut down each of 476 different DNA repair genes using a screening technique based on CRISPR interference

Based on these results, the researchers focused on a process called mismatch repair, which occurs naturally in cells to correct DNA mismatches that occur during DNA replication and repair

Based on this view, the team developed a new lead editing system, which they called PE4 and PE5, which included a protein, MLH1dn, which the researchers designed to temporarily inhibit a component of mismatch repair
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The researchers found that in cells undergoing mismatch repair, PE4 and PE5 greatly improved editing efficiency, and produced far fewer by-products compared with existing lead editing systems
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Finally, scientists invented PEmax, optimizing the structure and amino acid sequence of the lead editing mechanism
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Combining the improvements of PE4 and PE5 systems, PEmax and epegRNAs, the editing efficiency is increased by 10 to 100 times compared with the existing system
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Adamson said: "By combining the expertise of different research groups, we can figure out how lead editors work and optimize parts of the system
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" "This research is a wonderful example of how a basic understanding of how to promote experimental design
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Therapeutic application

Professor Liu said that in many cases, the combined improvement of epegRNAs and PE4/5/max makes it easier for scientists to create cell models of diseases, which is a key step in the development of treatment methods
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The team is currently using these systems to treat cell and animal genetic disease models, and will continue to explore the basic biological properties of these systems
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"All these innovations are synergistic," Professor Liu said.
"Through these improvements, we can edit important cell types efficiently and cleanly, and maybe one day we can help patients with genetic component diseases
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" These findings also indicate that , There are other strategies to further improve lead editing
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Original search:

Enhanced prime editing systems by manipulating cellular determinants of editing outcomes

Engineered pegRNAs improve prime editing efficiency