Special susceptibility to apoptosis of CD1a+ dendritic cell precursors differentiating from cord blood CD34+ progenitors.
We analyzed the effect of tumor necrosis factor (TNF)-alpha on the differentiation and viability of dendritic cells (DC) generated from cord blood CD34+ progenitors cultured for five days with GM-CSF, Flt-3 ligand (FL), and stem cell factor (SCF), and then with GM-CSF only [TNF(-) cultures]. Adding TNF-alpha from the start [TNF(+) cultures] potentiated progenitor cell proliferation and promoted early differentiation of CD1a+ DC precursors without affecting differentiation of CD14+ cells, which comprise bipotent precursors of DC and macrophages, nor of CD15+ granulocytic cells. Use of TNF-alpha was associated with increased cell mortality, which peaked on culture day 10 and mainly involved CD1a+ DC. Selective apoptosis of CD1a+ DC precursors was confirmed by showing that survival of day-7-sorted CD1a+CD14- cells from TNF(+) cultures was lower than that of CD1a-CD14+ cells. That similar findings were noted for sorted CD1a+CD14- cells of TNF(-) cultures, further cultured with GM-CSF without or with TNF-alpha, indicates that apoptosis of CD1a+ DC precursors was not induced by TNF-alpha. Apoptosis of CD1a+ DC precursors occurred after the cells had lost the capacity to incorporate bromodeoxyuridin. Finally, using higher GM-CSF concentrations or adding interleukin 3 (IL-3) improved viability of CD1a+ cells. Other cytokines, such as IL-4 and transforming growth factor (TGF)-beta1, were ineffective in this respect, though they promoted differentiation of CD1a+ DC. These results indicate that TNF-alpha promotes the differentiation of CD1a+ DC precursors, which display a high susceptibility to apoptosis that can be prevented by high concentrations of GM-CSF or use of IL-3, without affecting the differentiation of the CD14+ DC precursors.
Canque
B
B
Laboratoire de Biologie et Pathologie des Déficits Immunitaires, Faculté de Médecine et Hôpital Pitié-Salpêtière, Paris, France.
Camus
S
S
Yagello
M
M
Gluckman
J C
JC
D000328:Adult; D015703:Antigens, CD / Q000032:analysis*; D018949:Antigens, CD1 / Q000032:analysis*; D018952:Antigens, CD34 / Q000032:analysis*; D017209:Apoptosis; D002453:Cell Cycle / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000166:cytology* / Q000187:drug effects / Q000276:immunology; D005312:Fetal Blood / Q000166:cytology*; D005434:Flow Cytometry; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007231:Infant, Newborn; D007700:Kinetics; D007959:Lymphocyte Culture Test, Mixed; D008264:Macrophages / Q000166:cytology; D008565:Membrane Proteins / Q000494:pharmacology; D019089:Stem Cell Factor / Q000494:pharmacology; D013601:T-Lymphocytes / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D015703:Antigens, CD; D018949:Antigens, CD1; D018952:Antigens, CD34; D008565:Membrane Proteins; D019089:Stem Cell Factor; D014409:Tumor Necrosis Factor-alpha; C084881:flt3 ligand protein; D016178:Granulocyte-Macrophage Colony-Stimulating Factor