Mid-trimester fetal livers are a rich source of CD34+/++ cells for transplantation.
Human fetal livers (FL), between 16 and 24 weeks of gestation, were studied for their potential as a source of hematopoietic stem cells for prenatal and postnatal transplantation. In this report we give a quantitative evaluation of human FL as a source of candidate stem cells, and develop a protocol for the isolation of these cells free of microbial contaminants and almost free of mature T cells. Human FLs contained a median 1.9 x 10(9) viable cells and a mean of 1.3 x 10(8) CD34+/++ cells (range 1.1 x 10(7) to 4.7 x 10(8)). Regardless of gestational age, no significant differences were apparent in the numbers of total progenitors or in the numbers of candidate stem cells (CD34++ CD38- and CD34++CD4+), suggesting that the expansion in the liver of the early compartments of hematopoietic progenitors reaches a plateau after the sixteenth week of gestation. Colony-forming units culture (CFU-C) were found to range from 4.1 x 10(6) to 2.5 x 10(7) per FL. Positive selection of FL CD34++ cells was achieved using the Baxter Isolex 50 device. An average purity of 74% and yield of 29% of CD34+/++ cells was achieved. T cells were depleted by 99.95%, resulting in a mean of 6.5 x 10(3) T cells per processed liver. Analysis of candidate stem cell populations and primitive colony-forming cells (CFC) suggested a preferential enrichment of these cells over the total population of CD34+/++ cells. Processed CD34+/++cells were found to be sterile. In conclusion, purification of FL progenitors between 16 and 24 weeks of gestation results in a large number of early progenitors suitable for in utero and possibly post-natal transplantation.
Golfier
F
F
Department of Surgery, Fetal Treatment Center Research Laboratory, University of California, San Francisco, CA 94143-0570, USA.
Bárcena
A
A
Cruz
J
J
Harrison
M
M
Muench
M
M
D018952:Antigens, CD34 / Q000032:analysis; D002455:Cell Division; D002469:Cell Separation; D003114:Colony-Forming Units Assay; D005260:Female; D005434:Flow Cytometry; D005865:Gestational Age; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells; D006413:Hematopoietic System / Q000196:embryology; D006801:Humans; D007694:Killer Cells, Natural / Q000166:cytology; D008099:Liver / Q000166:cytology / Q000196:embryology*; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D013048:Specimen Handling; D013601:T-Lymphocytes / Q000166:cytology
D018952:Antigens, CD34