title: Megakaryocyte ex vivo expansion potential of three hematopoietic sources in serum and serum-free medium.
abstract: Megakaryocytes (MK) were expanded from purified human CD34+ cells obtained from three sources, bone marrow (BM), mobilized peripheral blood progenitor cells (PB), and umbilical cord (UC) blood. CD34+-selected cells were cultured for 12 days with 10 ng/ml thrombopoietin (TPO), 10 ng/ml IL-3, 10 ng/ml TPO + 10 ng/ml IL-3, or 200 ng/ml promegapoietin (PMP), a chimeric dual agonist of the c-Mpl and human IL-3 receptors. MK production was compared in serum-free versus human serum-supplemented liquid media. PMP and the combination of TPO and IL-3 (TPO + IL-3) increased MK production similarly. Culturing CD34+ cells with PMP in serum-free medium resulted in a twofold increase in MK yield compared with serum-supplemented medium. CD34+ cells from UC proliferated more than those from either BM or PB in liquid culture, resulting in much greater MK production under all conditions. Phenotypic analysis of the uncultured CD34+ cells showed that BM had a higher frequency of CD34+/CD41+ cells than PB or UC. TPO + IL-3 or PMP produced larger and greater numbers of BFU-MK and CFU-MK per seeded CD34+/CD41+ cell from UC than from either BM or PB. Thus, although uncultured CD34+-selected BM cells contained a higher frequency of committed mature MK progenitors, UC CD34+ cells had a greater proliferative capacity and, therefore, were more productive. PMP induced megakaryocytopoietic activity comparable to that achieved with TPO + IL-3 and may be useful for ex vivo expansion of MK for clinical trials.
authors.affiliation: Department of Cell and Molecular Biology, Northwestern University, Chicago, IL 60611, USA.
authors.forename: P
authors.initials: P
authors.lastname: Lefebvre
authors.forename: J N
authors.initials: JN
authors.lastname: Winter
authors.forename: L E
authors.initials: LE
authors.lastname: Kahn
authors.forename: J G
authors.initials: JG
authors.lastname: Giri
authors.forename: I
authors.initials: I
authors.lastname: Cohen
mesh_terms: D001853:Bone Marrow; D002454:Cell Differentiation; D002478:Cells, Cultured; D016895:Culture Media, Serum-Free; D005312:Fetal Blood; D006410:Hematopoiesis; D019650:Hematopoietic Stem Cell Mobilization; D006412:Hematopoietic Stem Cells / Q000473:pathology*; D006801:Humans; D008533:Megakaryocytes / Q000473:pathology*
chemical_list: D016895:Culture Media, Serum-Free