title: Correction of murine β-thalassemia after minimal lentiviral gene transfer and homeostatic in vivo erythroid expansion.
abstract: A challenge for gene therapy of genetic diseases is to maintain corrected cell populations in subjects undergoing transplantation in cases in which the corrected cells do not have intrinsic selective advantage over nontransduced cells. For inherited hematopoietic disorders, limitations include inefficient transduction of stem cell pools, the requirement for toxic myelosuppression, and a lack of optimal methods for cell selection after transduction. Here, we have designed a lentiviral vector that encodes human β-globin and a truncated erythropoietin receptor, both under erythroid-specific transcriptional control. This truncated receptor confers enhanced sensitivity to erythropoietin and a benign course in human carriers. Transplantation of marrow transduced with the vector into syngenic thalassemic mice, which have elevated plasma erythropoietin levels, resulted in long-term correction of the disease even at low ratios of transduced/untransduced cells. Amplification of the red over the white blood cell lineages was self-controlled and averaged ∼ 100-fold instead of ∼ 5-fold for β-globin expression alone. There was no detectable amplification of white blood cells or alteration of hematopoietic homeostasis. Notwithstanding legitimate safety concerns in the context of randomly integrating vectors, this approach may prove especially valuable in combination with targeted integration or in situ homologous recombination/repair and may lower the required level of pretransplantation myelosuppression.
authors: Institute of Emerging Diseases and Innovative Therapies (iMETI), Commissariat à l'Energie Atomique (CEA) de Fontenay-aux-Roses, 18 route du Panorama BP6, Fontenay aux Roses, France.
authors: Olivier
authors: O
authors: Negre
authors: Floriane
authors: F
authors: Fusil
authors: Charlotte
authors: C
authors: Colomb
authors: Shoshannah
authors: S
authors: Roth
authors: Beatrix
authors: B
authors: Gillet-Legrand
authors: Annie
authors: A
authors: Henri
authors: Yves
authors: Y
authors: Beuzard
authors: Frederic
authors: F
authors: Bushman
authors: Philippe
authors: P
authors: Leboulch
authors: Emmanuel
authors: E
authors: Payen
mesh_terms: D000818:Animals; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D004195:Disease Models, Animal; D004920:Erythropoiesis / Q000235:genetics; D015870:Gene Expression; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D018380:Hematopoietic Stem Cell Transplantation; D006706:Homeostasis; D006801:Humans; D016086:Lentivirus / Q000235:genetics; D051379:Mice; D017467:Receptors, Erythropoietin / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics; D014185:Transplantation, Isogeneic; D055544:beta-Globins / Q000235:genetics; D017086:beta-Thalassemia / Q000097:blood / Q000235:genetics / Q000628:therapy*
chemical_list: D017931:DNA Primers; D017467:Receptors, Erythropoietin; D011994:Recombinant Proteins; D055544:beta-Globins