Synergism between erythropoietin and interleukin-3 in the induction of hematopoietic stem cell proliferation and erythroid burst colony formation.
The influence of recombinant erythropoietin (Ep) and interleukin-3 (IL-3) on the proliferation and differentiation of murine hematopoietic stem and progenitor cells was investigated in serum-deprived cultures. The differentiation of progenitor cells, purified by collecting blast cell colonies from spleen cell cultures of 5-fluorouracil-treated mice, was evaluated by scoring the number and type of colonies appearing after eight days in semisolid culture. IL-3 induced the formation of both erythroid and granulocyte-macrophage colonies in a concentration-dependent fashion, the plateau being reached at 300 U/mL. However, concentrations of IL-3 alone that had little or no effect (less than or equal to 10 U/mL) induced maximal numbers of erythroid bursts in the presence of Ep (1.5 IU/mL). In the presence of Ep alone, no colonies were seen. Proliferation of quiescent hematopoietic stem cells, purified by cell sorting and evaluated by spleen colony assay (CFU-S), was investigated by measuring the total cell number and CFU-S content and the DNA histogram at 20 and 48 hours of liquid culture. Almost no cells or CFU-S survived 20 hours of incubation without the addition of IL-3. The presence of either IL-3 (400 U/mL) or the combination of EP and IL-3 (10 U/mL), supported the maintenance of nearly 40% of sorted CFU-S for 48 hours. Approximately 10% of these cells were in the S phase of the cell cycle at 20 hours and an increase in the total cell number per culture, but not in the CFU-S content, was detected at 48 hours. These data indicate that IL-3 exerts a differentiative and proliferative effect on early stem and progenitor cells, which is concentration dependent. At IL-3 concentrations, which had little or no activity alone, Ep acted synergistically to induce both proliferation of stem cells and differentiation of erythroid progenitors.
Migliaccio
G
G
Department of Hematology, Istituto Superiore Sanita, Rome.
Migliaccio
A R
AR
Visser
J W
JW
D000818:Animals; D001854:Bone Marrow Cells; D002455:Cell Division / Q000187:drug effects; D002469:Cell Separation; D003470:Culture Media; D004357:Drug Synergism; D004900:Erythroblasts / Q000166:cytology*; D004920:Erythropoiesis / Q000187:drug effects*; D004921:Erythropoietin / Q000494:pharmacology*; D005260:Female; D005312:Fetal Blood / Q000502:physiology; D005434:Flow Cytometry; D006098:Granulocytes / Q000166:cytology; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D007377:Interleukin-3 / Q000502:physiology*; D008264:Macrophages / Q000166:cytology; D051379:Mice; D008811:Mice, Inbred DBA; D011994:Recombinant Proteins / Q000494:pharmacology
D003470:Culture Media; D007377:Interleukin-3; D011994:Recombinant Proteins; D004921:Erythropoietin