Comparison of retroviral transduction efficiency in CD34+ cells derived from bone marrow versus G-CSF-mobilized or G-CSF plus stem cell factor-mobilized peripheral blood in nonhuman primates.
Hematopoietic stem cells (HSCs) are ideal targets for genetic manipulation in the treatment of several congenital and acquired disorders affecting the hematopoietic compartment. Although G-CSF-mobilized peripheral blood CD34(+) cells are the favored source of hematopoietic stem cells in clinical transplantation, this source of stem cells does not provide meaningful engraftment levels of genetically modified cells compared with G-CSF + stem cell factor (SCF)-mobilized cells in nonhuman primates. Furthermore, the use of G-CSF mobilization can have disastrous consequences in patients with sickle cell disease, a long-held target disorder for HSC-based gene therapy approaches. We therefore conducted a study to compare the levels of genetically modified cells attainable after retroviral transduction of CD34(+) cells collected from a bone marrow (BM) harvest with CD34(+) cells collected from a leukapheresis product after mobilization with G-CSF (n = 3) or G-CSF in combination with SCF (n = 3) in the rhesus macaque autologous transplantation model. Transductions were performed using retroviral vector supernatant on fibronectin-coated plates for 96 hours in the presence of stimulatory cytokines. BM was equal to or better than G-CSF-mobilized peripheral blood as a source of HSCs for retroviral transduction. Although the highest marking observed was derived from G-SCF + SCF-mobilized peripheral blood in two animals, marking in the third originated only from the BM fraction. These results demonstrate that steady-state BM is at least equivalent to G-CSF-mobilized peripheral blood as a source of HSCs for retroviral gene transfer and the only currently available source for patients with sickle cell disease.
Hematti
Peiman
P
Hematology Branch, NHLBI, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA.
Tuchman
Sascha
S
Larochelle
Andre
A
Metzger
Mark E
ME
Donahue
Robert E
RE
Tisdale
John F
JF
D000755:Anemia, Sickle Cell / Q000235:genetics; D000818:Animals; D018952:Antigens, CD34 / Q000096:biosynthesis*; D001854:Bone Marrow Cells / Q000166:cytology*; D018929:Cell Culture Techniques / Q000379:methods*; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors; D016179:Granulocyte Colony-Stimulating Factor / Q000378:metabolism*; D006098:Granulocytes / Q000166:cytology; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D008253:Macaca mulatta; D008954:Models, Biological; D016133:Polymerase Chain Reaction; D012190:Retroviridae / Q000235:genetics*; D019089:Stem Cell Factor / Q000378:metabolism; D013234:Stem Cells; D013997:Time Factors
D018952:Antigens, CD34; D019089:Stem Cell Factor; D016179:Granulocyte Colony-Stimulating Factor