TY - JOUR
T1 - Cord blood-derived hematopoietic progenitor cells
T2 - In vitro response to hematopoietic growth factors and their recruitment into the S-phase of the cell cycle
AU - Rosti, V.
AU - Malabarba, L.
AU - Ramajoli, I.
AU - Casula, S.
AU - Bergamaschi, G.
AU - Danova, M.
AU - Invernizzi, R.
AU - Pecci, A.
AU - Salvaneschi, L.
AU - Cazzola, M.
PY - 2000
Y1 - 2000
N2 - Background and Objectives. In the recent years many studies on the expansion of cord blood (CB)-derived progenitor cells have been performed, whereas less information is available on their cycling status. The objective of this study was to evaluate the cycling status of CB-derived colony-forming cells (CFC) and long-term culture-initiating cells (LTC-IC), and their recruitment into the S-phase of the cell cycle in response to a combination of cytokines. Design and Methods. CB-derived CFC and LTC-IC were first quantified by standard clonogenic assay and long-term culture, respectively. In a second set of experiments, CB-derived progenitor cells were incubated with interleukin(IL)-3, stem cell factor (SCF) and granulocyte colony-stimulating factor (G-CSF) and their cell cycle status assessed both by the cytosine arabinoside (Ara-C) suicide approach and by flow cytometric DNA analysis. Results. We found that only small proportions of both CFC and LTC-IC were in the S-phase of the cell cycle. These estimates were confirmed by flow cytometric DNA analysis, which showed that 96%±2% of CB-derived CD34+ cells were in G0/G1 and only 1.6%±0.4% in the S-phase. Staining of CD34+ cells with an anti-statin monoclonal antibody, a marker of the G0 phase, indicated that among CD34+ cells with a flow cytometric DNA content typical of the G0/G1 phase, 68%±7% of cells were in the G0 phase of the cell cycle. Twenty-four hour incubation with IL-3, SCF and G-CSF significantly increased the proportion of cells in the S-phase for both CFC and LTC-IC without inducing any loss in their number. Flow cytometric DNA analysis also showed an increase of CD34+ cells in the S-phase upon continuous exposure to these cytokines. Interpretations and Conclusions. Our findings indicate that: i) a small number of CB-derived CFC and LTC-IC are in the S-phase of the cell cycle; ii) a substantial number of CD34+ cells with a flow cytometric DNA content typical of the G0/G1 fraction are cycling, as they are found in the G1 phase of the cell cycle; iii) 24-hour incubation with IL-3, SCF and G-CSF can drive a proportion of progenitor cells into the S-phase without reducing their number. (C) 2000, Ferrata Storti Foundation.
AB - Background and Objectives. In the recent years many studies on the expansion of cord blood (CB)-derived progenitor cells have been performed, whereas less information is available on their cycling status. The objective of this study was to evaluate the cycling status of CB-derived colony-forming cells (CFC) and long-term culture-initiating cells (LTC-IC), and their recruitment into the S-phase of the cell cycle in response to a combination of cytokines. Design and Methods. CB-derived CFC and LTC-IC were first quantified by standard clonogenic assay and long-term culture, respectively. In a second set of experiments, CB-derived progenitor cells were incubated with interleukin(IL)-3, stem cell factor (SCF) and granulocyte colony-stimulating factor (G-CSF) and their cell cycle status assessed both by the cytosine arabinoside (Ara-C) suicide approach and by flow cytometric DNA analysis. Results. We found that only small proportions of both CFC and LTC-IC were in the S-phase of the cell cycle. These estimates were confirmed by flow cytometric DNA analysis, which showed that 96%±2% of CB-derived CD34+ cells were in G0/G1 and only 1.6%±0.4% in the S-phase. Staining of CD34+ cells with an anti-statin monoclonal antibody, a marker of the G0 phase, indicated that among CD34+ cells with a flow cytometric DNA content typical of the G0/G1 phase, 68%±7% of cells were in the G0 phase of the cell cycle. Twenty-four hour incubation with IL-3, SCF and G-CSF significantly increased the proportion of cells in the S-phase for both CFC and LTC-IC without inducing any loss in their number. Flow cytometric DNA analysis also showed an increase of CD34+ cells in the S-phase upon continuous exposure to these cytokines. Interpretations and Conclusions. Our findings indicate that: i) a small number of CB-derived CFC and LTC-IC are in the S-phase of the cell cycle; ii) a substantial number of CD34+ cells with a flow cytometric DNA content typical of the G0/G1 fraction are cycling, as they are found in the G1 phase of the cell cycle; iii) 24-hour incubation with IL-3, SCF and G-CSF can drive a proportion of progenitor cells into the S-phase without reducing their number. (C) 2000, Ferrata Storti Foundation.
KW - CD34
KW - Cell cycle
KW - CFC/LTC-IC
KW - Statin
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M3 - Article
C2 - 11268318
AN - SCOPUS:0033694960
VL - 85
SP - 18
EP - 25
JO - Haematologica
JF - Haematologica
SN - 0390-6078
IS - 11 SUPPL.
ER -