Kobayashi M, Laver J H, Kato T, Miyazaki H, Ogawa M
Department of Pediatrics and Medicine, Medical University of South Carolina, Charleston, USA.
Blood. 1996 Jul 15;88(2):429-36.
We have studied the effects of recombinant human thrombopoietin (TPO; mpl ligand) on the proliferation of human primitive hematopoietic progenitors in vitro. CD34+ cells were enriched for cell-cycle-dormant primitive progenitors by separation on the basis of expression of c-kit and CD38. In the presence of varying combinations of TPO, Steel factor (SF), and interleukin-3 (IL-3), CD34+/c-kit(low)/CD38neg/low cells produced fewer colonies than CD34+/c-kit(low)/CD38high cells. However, when cultured in suspension for 7 days and replated in methylcellulose culture for measurement of colony-forming cells, the former population generated more colony-forming cells than the latter. In suspension culture of CD34+/c-kit(low)/CD38neg/low cells, TPO acted synergistically with SF and/or IL-3 in support of the production of colony-forming cells for granulocyte/macrophage colonies, erythroid colonies, and mixed colonies. Culture studies of individual CD34+/c-kit(low)/CD38neg/low cells provided the evidence for the direct nature of the effects of TPO. When combined with SF, TPO showed stronger stimulation of production of progenitors in suspension culture than other early-acting factors, such as IL-6, IL-11, and granulocyte colony-stimulating factor (G-CSF). TPO may be an important cytokine for in vitro manipulation of human hematopoietic stem cells.
我们研究了重组人血小板生成素（TPO；mpl配体）对人原始造血祖细胞体外增殖的影响。通过基于c-kit和CD38表达进行分离，富集出处于细胞周期静止状态的原始祖细胞的CD34+细胞。在血小板生成素（TPO）、干细胞因子（SF）和白细胞介素-3（IL-3）的不同组合存在的情况下，CD34+/c-kit（低）/CD38阴性/低表达细胞形成的集落比CD34+/c-kit（低）/CD38高表达细胞少。然而，当在悬浮培养中培养7天，然后重新接种到甲基纤维素培养基中以测量集落形成细胞时，前一组产生的集落形成细胞比后一组多。在CD34+/c-kit（低）/CD38阴性/低表达细胞的悬浮培养中，TPO与SF和/或IL-3协同作用，支持粒细胞/巨噬细胞集落、红系集落和混合集落的集落形成细胞的产生。对单个CD34+/c-kit（低）/CD38阴性/低表达细胞的培养研究为TPO作用的直接性质提供了证据。当与SF联合使用时，TPO在悬浮培养中对祖细胞产生的刺激作用比其他早期作用因子，如IL-6、IL-11和粒细胞集落刺激因子（G-CSF）更强。TPO可能是体外操纵人造血干细胞的一种重要细胞因子。
