Tumor necrosis factor-alpha strongly potentiates interleukin-3 and granulocyte-macrophage colony-stimulating factor-induced proliferation of human CD34+ hematopoietic progenitor cells.
Previous studies have shown that tumor necrosis factors (TNFs) inhibit the proliferative effects of crude or purified colony-stimulating factors (CSFs) on low density human bone marrow cell fractions. In the present study we investigated the effects of TNF alpha on the growth of highly purified CD34+ human hematopoietic progenitor cells (HPC) in response to recombinant CSFs. In short-term liquid cultures (5 to 8 days), TNF alpha strongly potentiates interleukin-3 (IL-3) and granulocyte-macrophage-CSF (GM-CSF)-induced growth of CD34+ HPC, while it has no proliferative effect per se. Within 8 days, the number of viable cells obtained in TNF alpha-supplemented cultures is threefold higher than in cultures carried out with IL-3 or GM-CSF alone. Secondary liquid cultures showed that the potentiating effect of TNF alpha on IL-3-induced proliferation of CD34+ HPC does not result from an IL-3-dependent generation of TNF alpha responsive cells. Limiting dilution analysis indicates that TNF alpha increases both the frequency of IL-3 responding cells and the average size of the IL-3-dependent clones. The potentiating effect of TNF alpha on IL-3- and GM-CSF-dependent growth of CD34+ HPC is also observed in day 7 colony assays. Under these short-term culture conditions, TNF alpha does not appear to accelerate cell maturation as a precursor morphology is retained. Finally, TNF alpha inhibits the relatively weak growth-promoting effect of granulocyte-CSF (G-CSF), which acts on a more committed subpopulation of CD34+ HPC different from that recruited by IL-3 and GM-CSF. TNF beta displays the same modulatory effects as TNF alpha. Thus, TNFs appear to enhance the early stages of myelopoiesis.
Laboratory for Immunological Research, Schering-Plough (UNICET) Dardilly, France.
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C
Caux
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Saeland
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Favre
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Duvert
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Mannoni
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Banchereau
D015703:Antigens, CD / Q000032:analysis*; D018952:Antigens, CD34; D000943:Antigens, Differentiation / Q000032:analysis*; D001854:Bone Marrow Cells; D002455:Cell Division / Q000187:drug effects; D002469:Cell Separation; D003115:Colony-Stimulating Factors / Q000008:administration & dosage* / Q000037:antagonists & inhibitors / Q000494:pharmacology; D004357:Drug Synergism; D016179:Granulocyte Colony-Stimulating Factor; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D006133:Growth Substances / Q000008:administration & dosage*; D006410:Hematopoiesis / Q000187:drug effects*; D006801:Humans; D066298:In Vitro Techniques; D007377:Interleukin-3 / Q000008:administration & dosage*; D008233:Lymphotoxin-alpha / Q000008:administration & dosage; D014409:Tumor Necrosis Factor-alpha / Q000008:administration & dosage*
D015703:Antigens, CD; D018952:Antigens, CD34; D000943:Antigens, Differentiation; D003115:Colony-Stimulating Factors; D006133:Growth Substances; D007377:Interleukin-3; D008233:Lymphotoxin-alpha; D014409:Tumor Necrosis Factor-alpha; D016179:Granulocyte Colony-Stimulating Factor; D016178:Granulocyte-Macrophage Colony-Stimulating Factor