Factor VIII mutation repair and tolerance induction
Methods of treating hemophilia A in a subject with an F8 gene mutation, wherein the F8 gene is repaired and the resultant repaired gene, upon expression, confers improved coagulation functionality to the encoded FVIII protein of the subject compared to the non-repaired F8 gene. The invention also includes methods of inducing immune tolerance to a FVIII replacement product ((r)FVIII) in a subject having a FVIII deficiency, wherein the F8 gene mutation is repaired and the repaired gene, upon expression, provides for the induction of immune tolerance to an administered replacement FVIII protein product. The invention also includes isolated nucleic acids, vectors, recombinant viruses, cells, and pharmaceutical compositions to repair the F8 gene.
1. An in vitro or ex vivo method of repairing a mutated F8 gene in an endothelial or hepatocyte cell of a hemophilia A subject comprising:
providing an endothelial or hepatocyte cell of the subject comprising an inversion mutation in the mutated F8 gene;
introducing into the cell an isolated nucleic acid encoding a nuclease that targets the inversion mutation in the mutated F8 gene and creates a double stranded break in the mutated F8 gene; and a donor sequence comprising (i) a nucleic acid encoding a truncated FVIII polypeptide or (ii) a native F8 3′ splice acceptor site operably linked to a nucleic acid encoding a truncated FVIII polypeptide,
wherein the donor sequence is flanked by nucleic acid sequences homologous to the nucleic acid sequences upstream and downstream of the double stranded break in the F8 gene; and
obtaining a repaired endothelial or hepatocyte cell that comprises a repaired inversion mutation of the mutated F8 gene of the subject.
2. The method of claim 1 , wherein the repaired endothelial or hepatocyte cell of the subject comprising the corrected F8 gene is administered directly to the subject.
3. The method of claim 1 , wherein the isolated nucleic acids are administered ex vivo to endothelial or hepatocyte cells isolated from the subject.
4. The method of claim 1 , wherein the nuclease is a zinc finger nuclease (ZFN), Transcription Activator-Like Effector Nuclease (TALEN), or a CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)-associated (Cas) nuclease.
5. The method of claim 1 , wherein the nuclease targets intron 22 of the F8 gene.
6. The method of claim 1 , wherein the nuclease targets intron 1 of the F8 gene.
7. The method of claim 1 , wherein the nuclease targets the exon 22/intron 22 junction.
8. The method of claim 1 , wherein the nuclease targets the exon 1/intron 1 junction.
9. The method of claim 1 , wherein the subject's F8 mutation is an intron 22 inversion.
10. The method of claim 1 , wherein the subject's F8 mutation is a point mutation or a deletion.
11. The method of claim 1 , wherein the cells are endothelial cells.
12. The method of claim 1 , wherein the cells are blood outgrowth endothelial cells (BOECs) or liver sinusoidal endothelial cells (LSECs).
13. The method of claim 12 , wherein the BOECs are co-cultured with hepatocytes or LSECs, or both.
14. The method of claim 12 , wherein the BOECs are co-cultured with induced pluripotent stem cells.