Scientists from the Perelman School of Medicine at the University of Pennsylvania have discovered a new approach to genetic engineering, which offers improvements in efficiency, speed, and cellular toxicity reduction. This new technique uses protein fragments from some viruses to facilitate the delivery of CRISPR-Cas gene editing molecules into the cells and their DNA-containing nuclei with high efficiency and low toxicity. The team explored their new approach, called PAGE (peptide-assisted genome editing), in the journal Nature Biotechnology.
According to the researchers, the technique could impact the development of advanced cell therapies for cancer and other diseases. The team expects the method to help modify cells derived from patients, such as their T cells, to generate cell therapies. CAR T therapy is one such example, which uses modified immune cells to treat cancer.
CRISPR-Cas molecules are popular for genome editing experiments, whether by deleting old DNA and replacing it with new DNA or modifying genes to enhance cellular function. With their new method, the scientists could add genes that confer new properties to CAR T cells, such as the ability to recognize tumors or withstand the harsh tumor microenvironment.
The PAGE approach could see significant applications in basic scientific research, such as creating mouse models of diseases, which often require a time-consuming process of generating transgenic mice to introduce the gene-editing machinery into their DNA. The PAGE approach has high efficiency and low toxicity, making it possible to edit genes in ordinary lab mice rapidly. The scientists used peptides to deliver CRISPR-Cas molecules more efficiently through the outer membranes of primary human cells and into their nuclei.
The researchers found that combining two modified peptides from HIV and influenza viruses could be mixed with CRISPR-Cas molecules to achieve nearly 100% efficiency in getting them into primary human or mouse cells, depending on the cell type, with almost no toxicity or gene expression changes.
The scientists believe this new approach offers a simple, efficient, and well-tolerated delivery of CRISPR genome editing systems into primary cells, which can be a significant challenge. The authors also suggest that the PAGE approach could potentially be adapted in the future for the delivery of other genome-editing proteins or even protein-based drugs into primary cells. Ultimately, this new technique could have a far-reaching impact on the development of cell therapies and basic scientific research.