DNA Repair Profiling in T-cells Reveals Nonrandom Outcomes at Cas9-Mediated Breaks
Megan van Overbeek, Elaine Lau, Daniel Capurso, Lynda M. Banh, Matthew M. Carter, Matthew S. Thompson, Alexandra Lied, Stephen Smith, Scott Gradia, Christopher K. Fuller and Andrew P. May
Caribou Biosciences, Inc., Berkeley, CA 94710, USA
The repair outcomes at site-specific DNA double-strand breaks (DSBs) generated by the RNA-guided DNA endonuclease Cas9 determine how gene function is altered. Despite the widespread adoption of CRISPR-Cas9 technology to induce DSBs for genome engineering, the resulting repair products have not been examined in depth. Here, the DNA repair profiles of 223 sites in the human genome demonstrate that the pattern of DNA repair following Cas9 cutting at each site is nonrandom and consistent across experimental replicates and cell lines. Furthermore, the repair outcomes are determined by the targeted sequence rather than genomic context, enabling DNA repair profiling in cell lines to be used to anticipate repair outcomes in primary cells. In this study, the DNA repair profiles of therapeutically relevant targets in human primary T-cells are described.