RNA-triggered cell killing with CRISPR–Cas12a2

Selectively eradicating target cells on the basis of their genetic or transcriptional identity remains important in basic research, medicine, biotechnology and agriculture1–3. For applications involving bacteria, CRISPR nucleases offer promising options due to their ability to enact RNA-guided counterselection4–7; however, using these same nucleases for counterselection in eukaryotes has proven much more restrictive8–14. Here we show that Cas12a2, a recently discovered type V CRISPR nuclease, exhibits RNA-triggered DNA shredding15,16, and enables programmable and sequence-specific elimination of yeast and human cells expressing a target transcript. Triggering Cas12a2 elicits rampant double-stranded DNA breaks in trans, leading to cell death. Cell killing can be activated by a wide range of target transcripts, with no observed off-target activation. Leveraging this approach, we selectively eliminate cells that harbour human papillomavirus, cells that failed to undergo gene editing, or cells that encode a prevalent oncogenic point mutation in KRAS. These findings expand the CRISPR toolbox to allow the selective elimination of eukaryotic cells on the basis of their transcriptional profile. Cas12a2 enables RNA-triggered, sequence-specific killing of eukaryotic cells via widespread DNA shredding, allowing selective elimination of cells on the basis of gene expression, including virus-infected or mutation-bearing cells.