In vitro growth of human fetal CD34+ cells in the presence of various combinations of recombinant cytokines under serum-free culture conditions.
CD34+ cells were purified from midtrimester human fetal blood and adult bone marrow samples and seeded in serum-free fibrin-clot cultures in order to evaluate the number and the responsiveness to recombinant cytokines of pluripotent (CFU-GEMM), erythroid (BFU-E), megakaryocyte (BFU-meg and CFU-meg) and granulocyte/macrophage (CFU-GM) haemopoietic progenitor cells. The number of the different haemopoietic progenitors/1 x 10(3) CD34+ cells, except CFU-meg, was significantly higher in fetal blood than in adult bone marrow in cultures stimulated by any combination of cytokines including interleukin-3 (IL-3), granulocyte/macrophage colony stimulating factor (GM-CSF) or stem cell factor (SCF) plus erythropoietin (Epo). Nevertheless, whereas adult BFU-E showed a maximal growth in the presence of Epo plus IL-3 or Epo plus SCF, fetal BFU-E showed an optimal growth in the presence of Epo alone, the sensitivity of fetal BFU-E to suboptimal concentrations of Epo being approximately 10-15-fold higher than that of adult BFU-E. Addition of optimal concentrations of IL-3, GM-CSF or SCF, alone or in various combinations, to Epo-containing cultures induced a significant increase in both the number and size of fetal CFU-GEMM, and CFU-GM, and a parallel decrease of fetal BFU-E. Finally, SCF potently synergized with IL-3 in increasing the growth of both classes of fetal megakaryocyte progenitors, BFU-meg and CFU-meg.
Zauli
G
G
Institute of Human Anatomy, University of Ferrara, Italy.
Vitale
M
M
Visani
G
G
Marchisio
M
M
Milani
D
D
Capitani
S
S
D000328:Adult; D015703:Antigens, CD / Q000097:blood*; D018952:Antigens, CD34; D001854:Bone Marrow Cells; D002478:Cells, Cultured; D003115:Colony-Stimulating Factors / Q000494:pharmacology*; D016895:Culture Media, Serum-Free; D015672:Erythroid Precursor Cells / Q000166:cytology; D004921:Erythropoietin / Q000494:pharmacology; D005312:Fetal Blood / Q000166:cytology*; D006098:Granulocytes / Q000166:cytology; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects; D006801:Humans; D007700:Kinetics; D008264:Macrophages / Q000166:cytology; D008533:Megakaryocytes / Q000166:cytology; D011994:Recombinant Proteins / Q000494:pharmacology
D015703:Antigens, CD; D018952:Antigens, CD34; D003115:Colony-Stimulating Factors; D016895:Culture Media, Serum-Free; D011994:Recombinant Proteins; D004921:Erythropoietin