Methods and compositions for targeted cleavage and recombination
Disclosed herein are methods and compositions for targeted cleavage of a genomic sequence, targeted alteration of a genomic sequence, and targeted recombination between a genomic region and an exogenous polynucleotide homologous to the genomic region. The compositions include fusion proteins comprising a cleavage domain (or cleavage half-domain) and an engineered zinc finger domain and polynucleotides encoding same. Methods for targeted cleavage include introduction of such fusion proteins, or polynucleotides encoding same, into a cell. Methods for targeted recombination additionally include introduction of an exogenous polynucleotide homologous to a genomic region into cells comprising the disclosed fusion proteins.
1. An isolated cell comprising
(i) an exogenous non-naturally occurring nuclease comprising
first and second heterodimerizing FokI cleavage domains, wherein one of the first and second cleavage domains comprises a substitution mutation of amino acid 490 of the wild-type dimerization interface, and
a zinc finger DNA-binding protein that is heterologous to the first and second cleavage domains, wherein the zinc finger DNA-binding protein binds to a sequence in an HLA gene, and
(ii) an inactivated endogenous HLA gene, wherein the endogenous HLA gene comprises on or more nucleotide insertions, deletions or substitutions such that it is inactivated.
2. The cell of claim 1 , wherein the cell is a stem cell.
3. The cell of claim 1 , wherein the cell further comprises a transgene.
4. A method of grafting a cell into a host, the method comprising, administering a cell according to claim 1 to the host.
5. The method of claim 4 , where the cell further comprises a transgene.
6. The method of claim 4 , wherein the inactivated HLA gene encodes a Major Histocompatibility Complex (MHC) class 1 protein.
7. The method of claim 6 , wherein the inactivated HLA gene encodes an MHC β subunit gene (β2 microglobulin).
8. The method of claim 6 , wherein the cell is a stem cell.