title: Expansion and differentiation of human hematopoietic cells from static cultures through small-scale bioreactors.
abstract: Maintenance of the progenitor cells responsible for hematopoiesis has generally been accomplished using a feeder layer of stromal cells in stationary culture. Here, we compared the expansion of the total cell and progenitor cell populations using low-density mononuclear cells (LDMCs) obtained from human bone marrow in static culture (T-flasks) and in different cell culture bioreactors designed for the scale-up of mammalian cells. Static cultures were performed without the presence of a previously established stromal cell layer. Expansion of marrow in all cases was accomplished through the use of added cytokines such as IL-3, GM-CSF, and c-kit ligand. The results for the total cell expansion in static culture ranged from 4.4- to 32-fold. The cell number increase was affected by such factors as patient to patient variability, freeze-thawing, and the combination of cytokines used. Due to widespread use and the small amount of marrow needed, static cultures were used as a basis for comparison with other expansion systems. The cell culture systems used to evaluate the scale-up of marrow cultures included suspension, microcarrier, airlift, and hollow fiber bioreactors. Using identical media, cytokines, and feed schedules, LDMCs in the suspension bioreactor expanded to a value of 1.6 compared to a normalized value of 1.0 for static cultures for the two runs investigated. Expansion results for microcarrier cultures averaged 0.75 when compared to static cultures. A cell number increase in the airlift bioreactor resulted in an expansion which was 0.70 of the control static culture. Granulocyte-macrophage and erythroid progenitor assay data were also evaluated for the suspension, microcarrier, and airlift bioreactors.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: CytoMed, Inc., Cambridge, Massachusetts 02139.
authors.forename: C A
authors.initials: CA
authors.lastname: Sardonini
authors.forename: Y J
authors.initials: YJ
authors.lastname: Wu
mesh_terms: D001709:Biotechnology / Q000379:methods; D001854:Bone Marrow Cells; D002454:Cell Differentiation / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D002478:Cells, Cultured; D015672:Erythroid Precursor Cells / Q000166:cytology; D006098:Granulocytes / Q000166:cytology; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D008264:Macrophages / Q000166:cytology