Abstract: The present disclosure provides systems, compositions, and methods for simultaneously editing both strands of a double-stranded DNA sequence at a target site to be edited. Further provided herein are pharmaceutical compositions, polynucleotides, vectors, cells, and kits for simultaneously editing both strands of a double-stranded DNA sequence.

Abstract: The present disclosure provides systems, compositions, and methods for simultaneously editing both strands of a double-stranded DNA sequence at a target site to be edited. In some aspects, the systems comprise a first and second prime editor complex, wherein each of the first and second prime editor complexes comprises (1) a prime editor comprising (i) a nucleic acid programmable DNA binding protein (napDNAbp), and (ii) a polypeptide having an RNA-dependent DNA polymerase activity; and (2) a pegRNA comprising a spacer sequence, gRNA core, a DNA synthesis template, and a primer binding site, wherein the DNA synthesis template encodes a desired DNA sequence or a complement thereof, wherein the desired DNA sequence and the complement thereof form a duplex comprising an edited portion which integrates into the target site to be edited. In some aspects, the systems comprise a first, second, third, and fourth prime editor complex, each comprising a prime editor and a PEgRNA.

Abstract: The disclosure provides methods of deaminating adenosine and cytosine bases in a target nucleic acid sequence in an USH2A gene comprising contacting the USH2A gene with a base editor in association with a guide RNA (gRNA). In some aspects, base editing is used to restore US2HA function by disrupting a splice site in the USH2A gene sequence to induce skipping of an exon containing a mutation, while in other embodiments, base editing is used to restore US2HA function by correcting a point mutation e.g., in an exon) so as to correct mutations. The disclosure also provides complexes of adenosine base editors and guide RNAs, and complexes of cytidine base editors and guide RNAs. The disclosure further provides pharmaceutical compositions and cells comprising these complexes. The disclosure also provides vectors encoding these complexes, base editors, and gRNAs. In some embodiments, the methods and compositions provided herein are used to treat Usher syndrome and autosomal recessive retinitis pigmentosa (arRP).

Abstract: Provided herein are methods of delivering “split” Cas9 protein or nucleobase editors into a cell, e.g., via a recombinant adeno-associated vims (rAAV), to form a complete and functional Cas9 protein or nucleobase editor. The Cas9 protein or the nucleobase editor is split into two sections, each fused with one part of an intein system (e.g., intein-N and intein-C encoded by the dnaE-n and dnaE-c genes, respectively). Upon co-expression, the two sections of the Cas9 protein or nucleobase editor are ligated together via intein-mediated protein splicing. Nucleic acid molecules encoding the N-terminal portion of a Cas9 protein or a nucleobase editor fused to an intein, and nucleic acid molecules encoding the C-terminal portion of a Cas9 protein or nucleobase editor, are provided. Recombinant AAV vectors (e.

Abstract: Provided herein are methods of delivering “split” Cas9 protein or nucleobase editors into a cell, e.g., via a recombinant adeno-associated virus (rAAV), to form a complete and functional Cas9 protein or nucleobase editor. The Cas9 protein or the nucleobase editor is split into two sections, each fused with one part of an intein system (e.g., intein-N and intein-C encoded by dnaEn and dnaEc, respectively). Upon co-expression, the two sections of the Cas9 protein or nucleobase editor are ligated together via intein-mediated protein splicing. Recombinant AAV vectors and particles for the delivery of the split Cas9 protein or nucleobase editor, and methods of using such AAV vectors and particles are also provided.

Abstract: Provided herein are methods of delivering “split” Cas9 protein or nucleobase editors into a cell, e.g., via a recombinant adeno-associated virus (rAAV), to form a complete and functional Cas9 protein or nucleobase editor. The Cas9 protein or the nucleobase editor is split into two sections, each fused with one part of an intein system (e.g., intein-N and intein-C encoded by dnaEn and dnaEc, respectively). Upon co-expression, the two sections of the Cas9 protein or nucleobase editor are ligated together via intein-mediated protein splicing. Recombinant AAV vectors and particles for the delivery of the split Cas9 protein or nucleobase editor, and methods of using such AAV vectors and particles are also provided.

Abstract: Provided herein are methods of delivering “split” Cas9 protein or nucleobase editors into a cell, e.g., via a recombinant adeno-associated virus (rAAV), to form a complete and functional Cas9 protein or nucleobase editor. The Cas9 protein or the nucleobase editor is split into two sections, each fused with one part of an intein system (e.g., intein-N and intein-C encoded by dnaEn and dnaEc, respectively). Upon co-expression, the two sections of the Cas9 protein or nucleobase editor are ligated together via intein-mediated protein splicing. Recombinant AAV vectors and particles for the delivery of the split Cas9 protein or nucleobase editor, and methods of using such AAV vectors and particles are also provided.