Methods and compositions for enhancing targeted transgene integration
Disclosed herein are methods and compositions for enhancing insertion of transgene sequences encoding proteins that is aberrantly expressed in disease or disorder such as a lysosomal storage disease or a hemophilia by administering one or more topoisomerases inhibitors, one or more stabilizers of R loop formation or inhibitors of R-loop repair and/or one or more up-regulators of the TC-NER pathway to the target cell.
1. A method of integrating a transgene encoding a protein in a forward orientation into a selected endogenous genomic locus of an isolated population of liver or hematopoietic stem cells, the method comprising:
treating the isolated liver or hematopoietic stem cells with at least one topoisomerase inhibitor, the at least one topoisomerase inhibitor comprising camptothecin or etoposide;
introducing an AAV vector into the treated population of isolated liver or hematopoietic stem cells, the AAV vector comprising regions of homology to the selected endogenous genomic locus flanking the transgene, wherein the population of liver or hematopoietic stem cells is grown in the presence of the at least one topoisomerase inhibitor, such that the transgene is integrated into the selected endogenous locus in a forward orientation and expression of the transgene is driven an endogenous promoter and further wherein the transgene is integrated into the selected endogenous genomic locus and the protein is expressed from the endogenous promoter at levels increased at least 5-fold as compared to cells not grown in the presence of the at least one topoisomerase inhibitor.
2. The method of claim 1 , wherein the topoisomerase inhibitor inhibits topoisomerase I and/or II.
3. The method of claim 2 , further comprising treating the isolated liver or hematopoietic stem cells with doxorubicin, cisplatin, topotecan, irinotecan, tenipopside, mitoxantrone, etoposide phosphate, and/or topotecan hydrochloride.
4. The method of claim 1 , further comprising introducing one or more nucleases targeted to the selected endogenous genomic locus.
5. The method of claim 4 wherein the selected endogenous locus is an endogenous safe-harbor gene.
6. The method of claim 5 , wherein the safe harbor gene is selected from the group consisting of a CCR5 gene, an HPRT gene, an AAVS1 gene, a Rosa gene or an albumin gene.
7. The method of claim 6 , wherein the safe harbor gene is an albumin gene.
8. The method of claim 7 , wherein expression of the transgene is controlled by an endogenous albumin promoter.
9. The method of claim 4 , wherein the one or more nucleases comprise a zinc finger nuclease (ZFN), a TALEN or CRISPR/Cas nuclease system.
10. The method of claim 1 , wherein the protein is deficient or lacking in a subject with a lysosomal storage disease, hemophilia, epidermolysis bullosa, diabetes, cancer, clotting disorders or AAT deficient emphysema.
11. The method of claim 1 , wherein the protein is a Factor VII protein, a Factor VIII (F8) protein, a Factor IX (F.IX) protein, a Factor X protein, a glucocerebrosidase protein, an α galactosidase protein, an iduronate-2-sulfatase protein, an alpha-L iduronidase protein and/or a sphingomyelin phosphodiesterase protein.