CRISPR genome editing has served as a powerful tool to delete or modify DNA sequences and study the resulting effect. Now, researchers at the Gladstone Institutes and UC San Francisco (UCSF) have co-opted the CRISPR-Cas9 system to forcibly turn on genes rather than edit them in human immune cells. The method, known as CRISPRa, allowed them to discover genes that play a role in immune cell biology more thoroughly and quickly than before. The study, published in the journal Science, is the first to successfully use CRISPRa on a large scale in primary human cells, which are cells isolated directly from a person. In the new work, Marson, Steinhart and co-first author Ralf Schmidt, MD, worked with their colleagues to adapt CRISPRa and CRISPRi to work at high efficiency in primary T cells, something never done before. Improving the efficiency of delivery of the CRISPRa or CRISPRi machinery into cells was essential to enable genome-wide experiments and accelerate discovery. Marson’s lab is currently studying some of the individual genes identified in their screen, and working to further leverage CRISPRa and CRISPRi to discover genes that control other critical traits in human immune cells.
