Correction of deficient CD34+ cells from peripheral blood after mobilization in a patient with congenital erythropoietic porphyria.
Congenital erythropoietic porphyria (CEP) is an inherited disease due to a deficiency in the uroporphyrinogen III synthase (UROS), the fourth enzyme of the heme pathway. It is characterized by accumulation of uroporphyrin I in the bone marrow, peripheral blood, and other organs. The onset of most cases occurs in infancy and the main symptoms are cutaneous photosensitivity and hemolysis. For severe transfusion-dependent cases, when allogeneic cell transplantation cannot be performed, autografting of genetically modified primitive/stem cells is the only alternative. In the present study, efficient mobilization of peripheral blood primitive CD34(+) cells was performed on a young adult CEP patient. Retroviral transduction of this cell population with the therapeutic human UROS (hUS) gene resulted in both enzymatic and metabolic correction of CD34(+)-derived cells, as demonstrated by the increase in UROS activity and by a 53% drop in porphyrin accumulation. A 10-24% gene transfer efficiency was achieved in the most primitive cells, as demonstrated by the expression of enhanced green fluorescent protein (EGFP) in long-term culture-initiating cells (LTC-IC). Furthermore, gene expression remained stable during in vitro erythroid differentiation. Therefore, these results are promising for the future treatment of CEP patients by gene therapy.
Laboratoire de Pathologie Moléculaire et Thérapie Génique, EA 484, Université Victor Segalen Bordeaux 2, France.
F
F
Mazurier
F
F
Géronimi
I
I
Lamrissi-Garcia
C
C
Morel
E
E
Richard
C
C
Ged
A
A
Fontanellas
F
F
Moreau-Gaudry
M
M
Morey
H
H
de Verneuil
D018952:Antigens, CD34 / Q000235:genetics / Q000378:metabolism*; D001853:Bone Marrow / Q000201:enzymology; D015870:Gene Expression; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D005822:Genetic Vectors; D006412:Hematopoietic Stem Cells / Q000378:metabolism*; D006801:Humans; D016086:Lentivirus / Q000235:genetics; D017092:Porphyria, Erythropoietic / Q000628:therapy*; D011166:Porphyrins / Q000378:metabolism; D012190:Retroviridae / Q000235:genetics*; D014161:Transduction, Genetic; D014407:Tumor Cells, Cultured; D014576:Uroporphyrinogen III Synthetase / Q000235:genetics*
D018952:Antigens, CD34; D011166:Porphyrins; D014576:Uroporphyrinogen III Synthetase