Fetal bone marrow as a source of stem cells for in utero or postnatal transplantation.
We examined the potential of human fetal bone marrow (FBM) as a source of haematopoietic stem cells for transplantation. The median number of cells obtained between 20 and 24 weeks' gestation was 1.9 x 109 and a median 1.17 x 108 of these cells expressed CD34. Flow cytometry was also used to estimate the content of three different candidate stem cell populations in the tissues older than 20 weeks' gestation. A median 8.8 x 105 CD34++CD38- cells, 1.37 x 106 CD34++CD4+ cells and 2.20 x 106 CD34++CD90+ cells were detected. The content of colony-forming units culture (CFU-C) in the FBM ranged from 2.8 x 104 to 6.0 x 106 per fetus. The CFU-C content could be expanded 50-fold by culture for 1 week in serum-deprived medium and the growth factors kit ligand and granulocyte-macrophage colony-stimulating factor. Positive selection of FBM CD34+/++ cells was achieved using the Baxter Isolex 50 device. An average purity of 82% and yield of up to 19% of CD34+/++ cells was achieved. T cells were depleted by 99.84%. Analysis of candidate stem cell populations and primitive CFU-C suggested a preferential enrichment of these cells over the total population of CD34+/++ cells. All FBM samples were found to be free of microbial contamination at the time of harvest and after selection of CD34+/++ cells. Thus, FBM is a safe source of stem cells. The large number of progenitors and candidate stem cells that can be obtained from FBM makes it suitable for in utero and possibly postnatal transplantation.
Golfier
F
F
Department of Surgery, Fetal Treatment Center Research Laboratory at the University of California, San Francisco, CA 94143-0570, USA.
Bárcena
A
A
Harrison
M R
MR
Muench
M O
MO
D018952:Antigens, CD34; D001853:Bone Marrow / Q000196:embryology*; D003114:Colony-Forming Units Assay; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods*; D006801:Humans; D007694:Killer Cells, Natural; D018655:Lymphocyte Count; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D013234:Stem Cells / Q000276:immunology; D013601:T-Lymphocytes; D014015:Tissue Banks
D018952:Antigens, CD34