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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 105 (1980), S. 483-488 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We cultured human adult peripheral and umbilical cord blood mononuclear cells in methylcellulose and measured the synthetic rates of globin chains in individual erythropoietic bursts. Globin chains were labeled with 14C-amino acids in culture, separated by isoelectric focusing in slab gels containing 8 M urea and 3% Nonidet P-40, and quantitated by fluorographic methods. All bursts exhibited Gγ, Aγ, and β chains in varying ratios. Cumulative frequency distributions of individual bursts differing in the ratios of Gγ/(Gγ + Aγ) and γ/(γ + γ) approached normal distributions. These results indicated that perinatal hemoglobin switching and the hemoglobin switching of cultured adult erythropoietic precursors do not involve population changes in the precursors. Further, a positive correlation between γ/(γ + γ) and Gγ/(Gγ + Aγ) ratios of individual bursts existed in all of the samples. Switching between γ and β chains and switching of Gγ:Aγ ratios may share common regulatory mechanisms.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We have established a novel cell line, designated as TF-1, from a patient with erythroleukemia, which showed complete growth dependency on granulocyte-macrophage colony-stimulating factor (GM-CSF) or on interleukin-3 (IL-3) and carried a homogeneous chromosomal abnormality (54X). Erythropoietin (EPO) also sustained the short-term growth of TF-1, but did not induce erythroid differentiation. These three hematopoietic growth factors acted on TF-1 synergistically. Transforming growth factorβ and interferons inhibited the factor-dependent growth of TF-1 cells in a dose-dependent fashion, and monocyte-colony stimulating factor and interkeukin-1 enhanced the GM-CSF-dependent growth of TF-1. Ultrastructural studies revealed some very immature features in this cell line. Although TF-1 cells do not express glycophorin A or carbonyl anhydrase I, the morphological and cytochemical features, and the constitutive expression of globin genes, indicate the commitment of TF-1 to erythroid lineage. When induced to differentiate, TF-1 entered two different pathways. Specifically, hemin and delta-arninolevulinic acid induced hemoglobin synthesis, whereas TPA induced dramatic differentiation of TF-1 into macrophage-like cells. In summary, TF-1 is a cell lineof immature erythroid origin that requires GM-CSF, IL-3, or EPO for its growth and that has the ability to undergo differentiation into either more mature erythroid cells or into macrophage-like cells. TF-1 is auseful tool for analyzing the human receptors for IL-3, GM-CSF, and EPO or the signal transduction of these hemopoietic growth factors.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
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