Thrombopoietin augments ex vivo expansion of human cord blood-derived hematopoietic progenitors in combination with stem cell factor and flt3 ligand

Abstract

We studied the effects of stem cell factor (SCF) and flt3 ligand versus-host disease (GVHD). 1,4,6 However, the number of pro- factor (SCF) in combination with various cytokines, including

Primitive human hematopoietic cells give rise to differentially specified daughter cells upon their initial cell division

“…The latter cocktail has been shown to be particularly effective in maintaining and slightly expanding human HSCs in suspension cultures up to 7 days. [25][26][27] In order to compare the data presented here with our former results we performed our experiments in Dexter-type cultures.…”

Human cord blood-derived primitive progenitors are enriched in CD34+c-kit− cells: correlation between long-term culture-initiating cells and telomerase expression

“…171099, Nunc, Naperville, IL, USA), as reported elsewhere. [20][21][22][23][24][25] One milliliter of culture contained 200 sorted cells, 1.2% of 1500 centipoise methylcellulose (MTC, Shinetsu Chemical, Tokyo, Japan), 30% FCS, 1% deionized fraction V bovine serum albumin (BSA, Sigma Chemical, St Louis, MO, USA), 5 × 10 −5 mol/l 2-mercaptoethanol (2-ME, Sigma), and various combinations of CSFs. Final concentrations of each CSF were as follows: IL-3, 10 ng/ml; GM-CSF, 10 ng/ml; G-CSF, 20 ng/ml; Epo, 2 U/ml; SCF, 20 ng/ml.…”

“…On day 14 of incubation, all colonies were scored under an inverted microscope according to their typical morphologic features, as reported elsewhere. [20][21][22][23][24][25] The types of colonies identified in situ were granulocyte (G), macrophage (M), granulocyte/macrophage (GM), erythroid burst (B), eosinophil (Eo) and erythrocyte-containing mixed (CFU-Mix) colonies.…”

“…Both types of cells were then assayed for colony-forming cells (CFC) in the presence of optimal concentrations of IL-3,GM-CSF, G-CSF, Epo and SCF, as described elsewhere. [22][23][24][25] In this experiment, we also added 100 U/ml of IL-6, which had a maximal effect on the maturation of megakaryocyte progenitors in culture. 25 …”

Optimization of culture conditions to enhance transfection of human CD34+ cells by electroporation

“…22,25,[39][40][41] Numerous studies have shown that IL-3 has an important role in survival 42 and ex vivo expansion of primitive cells. 25,43 We chose to study culture conditions that would maintain the primitive state of stem cells yet maximize the proportion of CD34 + cells in S-phase in order to determine the optimal time for gene transfer by electroporation. Our goal was to maintain CD34 pluripotency and optimize the culture conditions for electroporation using enhanced green fluorescence protein (EGFP) as a reporter gene.…”