Morgan D A, Class R, Soslau G, Brodsky I
Department of Medicine, Allegheny University of the Health Sciences, Philadelphia, PA 19102, USA.
Exp Hematol. 1997 Dec;25(13):1378-85.
HU-3 is a bipotential cell line derived from the bone marrow of a patient with megakaryoblastic leukemia. Continuously proliferating cells evolved from cultures supplemented with nutrient medium containing human serum and granulocyte-macrophage (GM) colony-stimulating factor (CSF). Growth and viability of the HU-3 cell line was strictly dependent on the presence of GM-CSF, interleukin-3, or thrombopoietin (Tpo). Independent of the cytokine, the cells constitutively expressed a well-defined megakaryocyte phenotype, with 70-95% of the cells positive for CD4, CD34, and platelet glycoproteins Ib, IIb, and IIIa. Fewer than 10% of the cells had detectable erythroid glycophorin A. Erythropoiesis was induced in HU-3 parental cells and five clones harvested from culture medium containing GM-CSF by replacement of the growth-promoting cytokine with stem cell factor (SCF) and erythropoietin (Epo). During the first week of induction, the proliferating cells slowly acquired erythroid markers. Concomitant with a maturational growth arrest during the second week, there was a rapid accumulation of gamma and beta globin chains and benzidine reactive hemoglobin, as well as a distinct erythroid morphology. The culture declined after 12 days because of the transient effect of SCF in maintaining viability. Parental and cloned cells cultured for 7 days in Tpo-supplemented medium responded to the synergistic growth effect of SCF and Epo but were markedly suppressed in their yield of hemoglobinized cells. Recycling of the cells in GM-CSF for 4 days did not reverse the suppressive effect of Tpo. These results suggest a role for Tpo in the lineage commitment of erythromegakaryocytic progenitors by suppressing the erythroid potential. With its constitutive megakaryocyte phenotype and inducible erythroid potential, the self-renewing bipotential HU-3 cell line may represent one of the earliest stages in megakaryocytopoiesis before irreversible lineage commitment. The suppressive effect of Tpo on the erythroid potential of cloned HU-3 cells enhances the value of this cell line for deciphering the molecular and cellular events during lineage commitment of progenitor cells.
HU-3是一种双潜能细胞系,源自一名巨核母细胞白血病患者的骨髓。持续增殖的细胞由添加了含人血清和粒细胞巨噬细胞(GM)集落刺激因子(CSF)的营养培养基的培养物中演变而来。HU-3细胞系的生长和活力严格依赖于GM-CSF、白细胞介素-3或血小板生成素(Tpo)的存在。与细胞因子无关,这些细胞组成性地表达明确的巨核细胞表型,70%-95%的细胞CD4、CD34以及血小板糖蛋白Ib、IIb和IIIa呈阳性。少于10%的细胞可检测到红细胞血型糖蛋白A。通过用干细胞因子(SCF)和促红细胞生成素(Epo)替代促生长细胞因子,在HU-3亲代细胞和从含GM-CSF的培养基中收获的五个克隆中诱导出红细胞生成。在诱导的第一周,增殖细胞缓慢获得红细胞标志物。在第二周伴随着成熟生长停滞,γ和β珠蛋白链以及联苯胺反应性血红蛋白迅速积累,同时出现明显的红细胞形态。由于SCF维持活力的短暂作用,培养物在12天后衰退。在补充Tpo的培养基中培养7天的亲代细胞和克隆细胞对SCF和Epo的协同生长效应有反应,但血红蛋白化细胞的产量明显受到抑制。将细胞在GM-CSF中循环培养4天并不能逆转Tpo的抑制作用。这些结果表明Tpo通过抑制红细胞生成潜能在红巨核祖细胞的谱系定向中发挥作用。凭借其组成性的巨核细胞表型和可诱导的红细胞生成潜能,自我更新的双潜能HU-3细胞系可能代表巨核细胞生成中不可逆谱系定向之前的最早阶段之一。Tpo对克隆的HU-3细胞红细胞生成潜能的抑制作用增强了该细胞系在解读祖细胞谱系定向过程中的分子和细胞事件方面的价值。