AAV delivery of nucleobase editors
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.
1. A composition comprising:
(i) a first nucleotide sequence encoding an N-terminal portion of a nucleobase editor fused at its C-terminus to an intein-N; and
(ii) a second nucleotide sequence encoding an intein-C fused to the N-terminus of a C-terminal portion of the nucleobase editor, wherein the nucleobase editor comprises a deaminase fused to a CRISPR/Cas programmable DNA binding protein domain, wherein the N-terminal portion and the C-terminal portion may be joined to form the complete nucleobase editor.
2. The composition of claim 1 , wherein the deaminase is a cytosine deaminase.
3. The composition of claim 1 , wherein the deaminase is an adenosine deaminase.
4. The composition of claim 1 , wherein the intein-N comprises the amino acid sequence as set forth in any one of SEQ ID NOs: 351 and 355.
5. The composition of claim 1 , wherein the intein-C comprises the amino acid sequence as set forth in any one of SEQ ID NOs: 353 and 357.
6. The composition of claim 1 , wherein the first nucleotide sequence or the second nucleotide sequence further comprises a nucleotide encoding a guide RNA (gRNA) operably linked to a promoter.
7. The composition of claim 1 , wherein the first nucleotide sequence or second nucleotide sequence are operably linked to a nucleotide sequence encoding at least one bipartite nuclear localization signal.
8. The composition of claim 7 , wherein the bipartite nuclear localization signal comprises an amino acid sequence selected from the group consisting of:
KRPAATKKAGQAKKKK,
(SEQ ID NO: 344)
KKTELQTTNAENKTKKL,
(SEQ ID NO: 345)
KRGINDRNFWRGENGRKTR,
(SEQ ID NO: 346)
and
RKSGKIAAIVVKRPRK.
(SEQ ID NO: 347)
9. The composition of claim 8 , wherein the bipartite nuclear localization signal comprises the amino acid sequence as set forth in SEQ ID NO: 344.
10. The composition of claim 1 , wherein the nucleobase editor comprises a cytosine deaminase fused to the N-terminus of a catalytically inactive Cas9 or a Cas9 nickase.
11. The composition of claim 10 , wherein the cytosine deaminase is selected from the group consisting of: APOBEC1, APOBEC3, activation induced deaminase (AID), and pmCDA1.
12. The composition of claim 10 , wherein the nucleobase editor further comprises a uracil glycosylase inhibitor (UGI).
13. The composition of claim 12 , wherein the second nucleotide sequence of (ii) further comprises a nucleotide sequence encoding the uracil glycosylase inhibitor (UGI) at the 3′ end of the second nucleotide sequence.
14. The composition of claim 12 , wherein the first nucleotide sequence of (i) further comprises a nucleotide sequence encoding the uracil glycosylase inhibitor (UGI) at the 5′ end of the first nucleotide sequence.
15. The composition of claim 12 , wherein the UGI comprises the amino acid sequence of any one of SEQ ID NOs: 299-302.
16. The composition of claim 12 , wherein the UGI comprises an amino acid sequence having at least 95% identity to any of the sequences set forth in SEQ ID NOs: 299-302.
17. The composition of claim 1 , wherein the first nucleotide sequence and the second nucleotide sequence are on different vectors.
18. The composition of claim 17 , wherein each of the different vectors is a genome of a recombinant adeno-associated virus (rAAV).
19. The composition of claim 18 , wherein each of the different vectors are packaged in a rAAV particle.
20. The composition of claim 1 , wherein the nucleobase editor comprises an amino acid sequence having at least 90% identity to any of the sequences set forth in SEQ ID NOs: 303-313 or 399-406.
21. The composition of claim 20 , wherein the nucleobase editor comprises the amino acid sequence set forth in SEQ ID NO: 399.
22. The composition of claim 1 , wherein the nucleobase editor comprises an amino acid sequence having at least 90% identity to any of the sequences set forth in SEQ ID NOs: 323-342, 458-478, or 480.
23. The composition of claim 22 , wherein the nucleobase editor comprises the amino acid sequence set forth in SEQ ID NO: 478.
24. The composition of claim 1 , wherein the first nucleotide sequence or the second nucleotide sequence further comprises a transcriptional terminator.
25. The composition of claim 24 , wherein the transcriptional terminator is a transcriptional terminator from a bGH gene, hGH gene, or SV40 gene.
26. The composition of claim 25 , wherein the transcriptional terminator is from a bGH gene.
27. The composition of claim 24 , wherein the first nucleotide sequence or the second nucleotide sequence further comprises a woodchuck hepatitis posttranscriptional regulatory element (WPRE) inserted 5′ of the transcriptional terminator.
28. An isolated cell comprising the composition of claim 1 .
29. The isolated cell of claim 28 further comprising the N-terminal portion of the nucleobase editor encoded by the first nucleotide sequence of the composition and the C-terminal portion of the nucleobase editor encoded by the second nucleotide sequence of the composition joined together to form the nucleobase editor.
30. The isolated cell of claim 28 , wherein the cell is a human cell.
31. The composition of claim 1 , wherein the deaminase is fused to the N-terminus of the CRISPR/Cas programmable DNA binding protein domain.
32. The composition of claim 1 , wherein the nucleobase editor comprises a cytosine deaminase fused to the N-terminus of a Cpf1 protein.
33. A method comprising: contacting a cell with the composition of claim 1 , wherein the contacting results in the delivery of the first nucleotide sequence and the second nucleotide sequence into the cell.
34. A method comprising:
administering to a subject in need thereof a therapeutically effective amount of the composition of claim 1 .
35. The method of claim 34 , wherein the subject has a disease or disorder.
36. The method of claim 35 , wherein the disease or disorder is selected from the group consisting of cystic fibrosis, phenylketonuria, epidermolytic hyperkeratosis (EHK), chronic obstructive pulmonary disease (COPD), Charcot-Marie-Toot disease type 4J, neuroblastoma (NB), von Willebrand disease (vWD), myotonia congenital, hereditary renal amyloidosis, dilated cardiomyopathy, hereditary lymphedema, familial Alzheimer's disease, prion disease, chronic infantile neurologic cutaneous articular syndrome (CINCA), and desmin-related myopathy (DRM).