title: Expansion in bioreactors of human progenitor populations from cord blood and mobilized peripheral blood.
abstract: Umbilical cord blood (UCB) and mobilized peripheral blood (MPB) provide an alternate source to bone marrow for transplantation. Expansion in vitro of stem/progenitor cell populations from these sources may provide adult-sized grafts otherwise not attainable because of the limited cell numbers available in the case of UCB or because of numerous rounds of apheresis required for sufficient MPB cells. We asked whether continuous perfusion culture could be employed in ex vivo expansion to produce clinically relevant numbers of stem/progenitor cells from these sources. To evaluate MPB, 1-10 million leukocytes, from patients who had received either granulocyte colony-stimulating factor (G-CSF) or cyclophosphamide and granulocyte-macrophage colony-stimulating factor (GM-CSF), were inoculated into bioreactors, with or without irradiated, allogeneic stroma. The growth factor combination in the perfusion medium consisted of interleukin-3 (IL-3), stem cell factor (SCF), GM-CSF and erythropoietin (Epo). Under the best conditions tested, total cell numbers, granulocyte-macrophage colony-forming units (CFU-GM), and long-term culture-initiating cell (LTC-IC) populations were expanded by about 50-, 80-, and 20-fold, respectively, over 14 days. At low cell inocula (1 million), the presence of stroma enhanced the expansion of total cells and CFU-GM but not of LTC-IC. When SCF was not included in the medium, both total cells and CFU-GM expanded to a much lesser extent, but again the expansion of LTC-IC was not affected. At the higher cell inoculum (10 million), expansions of total cells and CFU-GM were equivalent with or without stroma. To evaluate UCB, cells were placed into bioreactors with or without irradiated, allogeneic stroma, and the bioreactors were perfused with medium containing the four standard growth factors. After 6-14 days, in several independent experiments, 20-24 million cells were harvested from bioreactors perfused with SCF-containing medium, irrespective of the presence or absence of preformed stroma. Similarly, in reactors perfused with SCF-containing medium (with or without stroma), an average 40- to 60-fold expansion of CFU-GM was obtained, yielding an average of 1.5-1.8 x 10(5) CFU-GM per reactor. Harvested cells were thus up to 40-fold enriched in CFU-GM in comparison to the inoculum. In the absence of SCF, cell expansions averaged 1.5- to 2-fold, and CFU-GM were expanded only 10- to 14-fold by day 14. As before, the presence of preformed stroma did not affect either cell or CFU-GM yields, provided the cell inoculum was at least 4.5 million cells.(ABSTRACT TRUNCATED AT 400 WORDS)
authors.affiliation: Aastrom Biosciences, Inc., Ann Arbor, Michigan 48106, USA.
authors.forename: G
authors.initials: G
authors.lastname: Van Zant
authors.forename: S A
authors.initials: SA
authors.lastname: Rummel
authors.forename: M R
authors.initials: MR
authors.lastname: Koller
authors.forename: D B
authors.initials: DB
authors.lastname: Larson
authors.forename: I
authors.initials: I
authors.lastname: Drubachevsky
authors.forename: M
authors.initials: M
authors.lastname: Palsson
authors.forename: S G
authors.initials: SG
authors.lastname: Emerson
mesh_terms: D000328:Adult; D001773:Blood Cells; D001853:Bone Marrow / Q000502:physiology / Q000528:radiation effects; D002452:Cell Count; D002454:Cell Differentiation / Q000187:drug effects; D003238:Connective Tissue / Q000502:physiology / Q000528:radiation effects; D046508:Culture Techniques / Q000295:instrumentation*; D004357:Drug Synergism; D004921:Erythropoietin / Q000494:pharmacology; D005312:Fetal Blood / Q000166:cytology*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006410:Hematopoiesis / Q000187:drug effects; D016298:Hematopoietic Cell Growth Factors / Q000494:pharmacology; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects; D006801:Humans; D007231:Infant, Newborn; D007377:Interleukin-3 / Q000494:pharmacology; D009369:Neoplasms / Q000097:blood; D010477:Perfusion; D019089:Stem Cell Factor
chemical_list: D016298:Hematopoietic Cell Growth Factors; D007377:Interleukin-3; D019089:Stem Cell Factor; D004921:Erythropoietin; D016178:Granulocyte-Macrophage Colony-Stimulating Factor