Method for chemoselection
A method of radiation-free hematopoietic stem cell (HSC) transplantation comprises administering to a mammalian subject one or two doses of 2 to 10 mg/kg body weight of a purine base analog, such as 6TG as a pre-conditioning step. The method further comprises engrafting into the subject hypoxanthine-guanine phosphoribosyltransferase (HPRT)-deficient donor HSCs within 48 to 72 hours of the pre-conditioning step; and administering to the subject about 1 to 5 mg/kg of the purine base analog every two to four days for two to eight weeks following the engrafting step. The method is performed in the absence of pre-conditioning via radiation. The subject is therefore not treated with myeloablative radiation in preparation for transplantation, and thus the subject is free of myeloablative radiation-induced toxicity.
1. A method of radiation-free hematopoietic stem cell (HSC) transplantation, the method comprising:
(a) engrafting into a pre-conditioned mammalian subject hypoxanthine-guanine phosphoribosyltransferase (HPRT)-deficient donor HSCs; and
(b) immediately administering to the subject about 1 to 5 mg/kg of a purine base analog selected from 6-thioguanine (6TG), 6-mercaptopurine (6-MP), or azathiopurine (AZA) every two to four days for two to eight weeks;
wherein the method is performed in the absence of pre-conditioning via radiation, and wherein the HSCs have been genetically modified.
2. The method of claim 1 , wherein the HSCs have been genetically modified to correct a hereditary genetic defect, to alter drug sensitivity of normal bone marrow to cytotoxic drugs, to confer resistance to infectious microorganisms that affect lymphohematopoietic cells, to replace or re-set the endogenous immune system, or to combat lymphohematopoietic malignancies through replacement of endogenous bone marrow and induction of a graft-vs.-leukemia/lymphoma effect.
3. The method of claim 1 , wherein the subject is human.
4. The method of claim 1 , wherein the subject has a hereditary or genetic disorder.
5. The method of claim 1 , wherein the subject has an acquired disease affecting lymphohematopoietic cells.
6. The method of claim 5 , wherein the disease or disorder is human immunodeficiency virus (HIV) infection or acquired immune deficiency syndrome (AIDS).
7. The method of claim 5 , wherein the disease or disorder is a lymphohematopoietic malignancy.
8. The method of claim 1 , wherein the disease or disorder is of hematopoietic or thrombopoietic or lymphopoietic system.
9. The method of claim 8 , wherein the disease or disorder of the hematopoietic system is a hemoglobinopathy.
10. The method of claim 1 , wherein the method further comprises bone marrow transplantation.
11. The method of claim 1 , wherein the purine base analog is 6TG.
12. The method of claim 1 , wherein the total 6TG dosage administered to the subject in the administering of step (b) does not exceed 105 mg.
13. The method of claim 1 , wherein the total 6TG dosage administered to the subject in the administering of step (b) does not exceed 75 mg.
14. The method of claim 1 , wherein the administering of step (b) is performed every 3 days and for not more than four weeks following the engrafting step.
15. The method of claim 1 , wherein the subject exhibits over 75% genetically modified hematopoietic cells.
16. The method of claim 1 , wherein the subject exhibits over 95% genetically modified hematopoietic cells.
17. The method of claim 1 , wherein the HPRT-deficient HSCs to be transplanted have been rendered HPRT-deficient via introduction of sequences encoding zinc finger nucleases (ZFNs), transcriptional activator-like effector nucleases (TALENs), small fragment homologous recombination (SFHR) template strands, inhibitory RNAs (siRNAs) or microRNAs (miRNAs), antisense RNAs, trans-splicing RNAs, ribozymes, intracellular antibodies, or dominant-negative or competitive inhibitor proteins.
18. The method of claim 1 , wherein the HPRT-deficient HSCs to be transplanted have been rendered HPRT-deficient via introduction of sequences encoding zinc finger nucleases (ZFNs).
19. The method of claim 1 , wherein the HPRT-deficient HSCs to be transplanted have been rendered HPRT-deficient via introduction of sequences encoding transcriptional activator-like effector nucleases (TALENs).
20. The method of claim 1 , wherein the HPRT-deficient HSCs to be transplanted have been rendered HPRT-deficient via introduction of sequences encoding inhibitory RNAs (siRNAs).
21. The method of claim 1 , wherein the transplanted HSCs are autologous or syngeneic.
22. The method of claim 1 , wherein the transplanted HSCs are allogeneic.
23. The method of claim 1 , wherein the subject is not treated with myeloablative radiation.
24. A method of treating symptoms of a disease or disorder in a subject, the method comprising:
(a) administering a pre-conditioning treatment to the subject;
(b) engrafting into the subject hypoxanthine-guanine phosphoribosyltransferase (HPRT)-deficient donor HSCs; and
(c) immediately administering to the subject about 1 to 5 mg/kg of a purine base analog selected from 6-thioguanine (6TG), 6-mercaptopurine (6-MP), or azathiopurine (AZA) every two to four days for two to eight weeks;
wherein the method is performed in the absence of pre-conditioning via radiation, and wherein the HSCs have been genetically modified to correct a hereditary genetic defect, to alter drug sensitivity of normal bone marrow to cytotoxic drugs, to confer resistance to infectious microorganisms that affect lymphohematopoietic cells, to replace or re-set the endogenous immune system, or to combat lymphohematopoietic malignancies through replacement of endogenous bone marrow and induction of a graft-vs.-leukemia/lymphoma effect.
25. The method of claim 24 , wherein the disease or disorder is human immunodeficiency virus (HIV) infection or acquired immune deficiency syndrome (AIDS).
26. The method of claim 24 , wherein the disease or disorder is a lymphohematopoietic malignancy.
27. The method of claim 24 , wherein the disease or disorder is of hematopoietic or thrombopoietic or lymphopoietic system.
28. The method of claim 27 , wherein the disease or disorder of the hematopoietic system is a hemoglobinopathy.
29. The method of claim 24 , wherein the method further comprises bone marrow or hematopoietic stem cell transplantation.
30. The method of claim 24 , wherein the subject is human.
31. The method of claim 24 , wherein the purine base analog is 6TG.
32. The method of claim 24 , wherein the administering of step (c) is performed every 3 days and for not more than four weeks following the engrafting step.
33. The method of claim 24 , wherein the subject exhibits over 75% genetically modified hematopoietic cells.
34. The method of claim 24 , wherein the subject exhibits over 95% genetically modified hematopoietic cells.
35. The method of claim 24 , wherein the HPRT-deficient HSCs to be transplanted have been rendered HPRT-deficient via introduction of sequences encoding zinc finger nucleases (ZFNs), transcriptional activator-like effector nucleases (TALENs), small fragment homologous recombination (SFHR) template strands, inhibitory RNAs (siRNAs) or microRNAs (miRNAs), antisense RNAs, trans-splicing RNAs, ribozymes, intracellular antibodies, or dominant-negative or competitive inhibitor proteins.
36. The method of claim 24 , wherein the HPRT-deficient HSCs to be transplanted have been rendered HPRT-deficient via introduction of sequences encoding zinc finger nucleases (ZFNs).
37. The method of claim 24 , wherein the HPRT-deficient HSCs to be transplanted have been rendered HPRT-deficient via introduction of sequences encoding transcriptional activator-like effector nucleases (TALENs).
38. The method of claim 24 , wherein the HPRT-deficient HSCs to be transplanted have been rendered HPRT-deficient via introduction of sequences encoding inhibitory RNAs (siRNAs).
39. The method of claim 24 , wherein the transplanted HSCs are autologous or syngeneic.
40. The method of claim 24 , wherein the transplanted HSCs are allogeneic.
41. The method of claim 24 , wherein the subject is not treated with myeloablative radiation.