Engineering CRISPR against RNA Viruses

Treatment with Cas13d-NCS prevents the spread of SARS-CoV-2 (green)
“Here, we [at Helmholtz, Munich] show that the nuclear localization of Cas13d crRNAs is the fundamental cause of Cas13d’s nuclear preference. To address this limitation, we engineered nucleocytoplasmic shuttling Cas13d (Cas13d-NCS). Cas13d-NCS transfers nuclear crRNAs to the cytosol, where the protein/crRNA complex binds and degrades complementary target RNAs. We screened various designs of shuttling proteins and characterized multiple design parameters of the best-performing system. We show that Cas13d-NCS is superior for degrading mRNAs and a self-replicating RNA derived from the Venezuelan equine encephalitis (VEE) RNA virus. Ultimately, we harnessed Cas13d-NCS to completely block the replication of various SARS-CoV-2 strains. Cas13d-NCS, therefore, enables the rational manipulation of the subcellular localization of a CRISPR system.” MORE
Image Credit: Wolfgang Wurst and Innovations Report