In:
The Journal of Gene Medicine, Wiley, Vol. 5, No. 9 ( 2003-09), p. 737-747
Abstract:
Erythropoietic protoporphyria (EPP) is an inherited disease characterised by a ferrochelatase (FECH) deficiency, the latest enzyme of the heme biosynthetic pathway, leading to the accumulation of toxic protoporphyrin in the liver, bone marrow and spleen. We have previously shown that a successful gene therapy of a murine model of the disease was possible with lentiviral vectors even in the absence of preselection of corrected cells, but lethal irradiation of the recipient was necessary to obtain an efficient bone marrow engraftment. To overcome a preconditioning regimen, a selective growth advantage has to be conferred to the corrected cells. Methods We have developed a novel bicistronic lentiviral vector that contains the human alkylating drug resistance mutant O 6 ‐methylguanine DNA methyltransferase (MGMT G156A) and FECH cDNAs. We tested their capacity to protect hematopoietic cell lines efficiently from alkylating drug toxicity and correct enzymatic deficiency. Results EPP lymphoblastoid (LB) cell lines, K562 and cord‐blood‐derived CD34 + cells were transduced at a low multiplicity of infection (MOI) with the bicistronic constructs. Resistance to O 6 ‐benzylguanine (BG)/ N , N ′‐bis(2‐chloroethyl)‐ N ‐nitrosourea (BCNU) was clearly shown in transduced cells, leading to the survival and expansion of provirus‐containing cells. Corrected EPP LB cells were selectively amplified, leading to complete restoration of enzymatic activity and the absence of protoporphyrin accumulation. Conclusions This study demonstrates that a lentiviral vector including therapeutic and G156A MGMT genes followed by BG/BCNU exposure can lead to a full metabolic correction of deficient cells. This vector might form the basis of new EPP mouse gene therapy protocols without a preconditioning regimen followed by in vivo selection of corrected hematopoietic stem cells. Copyright © 2003 John Wiley & Sons, Ltd.
Type of Medium:
Online Resource
ISSN:
1099-498X
,
1521-2254
Language:
English
Publisher:
Wiley
Publication Date:
2003
detail.hit.zdb_id:
2002203-7
SSG:
12
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