Human hematopoietic stem cells stimulated to proliferate in vitro lose engraftment potential during their S/G2/M transit and do not reenter G0
Human hematopoietic stem cells stimulated to proliferate in vitro lose engraftment potential during their S/G2/M transit and do not reenter G0
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DOI：
10.1182/blood.v96.13.4185.h8004185_4185_4193
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发表时间：
2000-12-15
期刊：
影响因子：
20.3
通讯作者：
Eaves, CJ
中科院分区：
文献类型：
--
作者：
Glimm, H;Oh, IL;Eaves, CJ
了解造血干细胞植入的调控机制对培养和转基因移植的临床应用至关重要。在NOD/SCID小鼠中具有淋巴髓样再生活性的人脐带血（CB）细胞最近被证明在含有Flt 3-配体、Steel因子、白细胞介素3（IL-3）、IL-6和粒细胞集落刺激因子的无血清培养物中6天内经历多次自我更新分裂。目前的研究表明，在第5天，可移植干细胞活性仅限于G（1）部分，即使相同培养物中的集落形成细胞（CFC）和长期培养起始细胞（LTC-IC）在G（0）/G（1）和S/G（2）/M之间分布大致相等。有趣的是，由其低水平的Hoechst 33342和派洛宁Y染色以及减少的Kl 67和细胞周期蛋白D表达（代表培养的CB群体的21%）定义的G（0）细胞包括一些成熟的红系CFC，但非常少的原始CFC、LTC-IC或再增殖细胞。虽然这些发现表明体内干细胞归巢中的细胞周期相关变化，但培养的G（0）/G（1）和S/G（2）/M CD 34（+）CB细胞在VLA-4、VLA-5或CXCR-4的表达水平上没有差异。在存在一定浓度的转化生长因子β（1）的情况下，将这些细胞进一步孵育1天，所述浓度的转化生长因子β（1）增加G（0）/G（1），选择性沉默增殖的人造血干细胞的可移植性的细胞周期相关机制的证明为离体操作的移植物的未来改进提出了挑战和机遇。（Blood，2000;96：4185-4193）（C）2000年，美国血液学会。
An understanding of mechanisms regulating hematopoietic stem cell engraftment is of pivotal importance to the clinical use of cultured and genetically modified transplants. Human cord blood (CB) cells with lymphomyeloid repopulating activity in NOD/SCID mice were recently shown to undergo multiple self-renewal divisions within 6 days in serum-free cultures containing Flt3-ligand, Steel factor, interleukin 3 (IL-3), IL-6, and granulocyte colony-stimulating factor. The present study shows that, on the fifth day, the transplantable stem cell activity is restricted to the G(1) fraction, even though both colony-forming cells (CFCs) and long-term culture-initiating cells (LTC-ICs) in the same cultures are approximately equally distributed between G(0)/G(1) and S/G(2)/M. Interestingly, the G(0) cells defined by their low levels of Hoechst 33342 and Pyronin Y staining, and reduced Kl67 and cyclin D expression (representing 21% of the cultured CB population) include some mature erythroid CFCs but very few primitive CFCs, LTC-ICs, or repopulating cells. Although these findings suggest a cell cycle-associated change in in vivo stem cell homing, the cultured G(0)/G(1) and S/G(2)/M CD34(+) CB cells exhibited no differences in levels of expression of VLA-4, VLA-5, or CXCR-4, Moreover, further incubation of these cells for 1 day in the presence of a concentration of transforming growth factor beta (1) that increased the G(0)/G(1) fraction did not enhance detection of repopulating cells, The demonstration of a cell cycle-associated mechanism that selectively silences the transplantability of proliferating human hematopoietic stem cells poses both challenges and opportunities for the future improvement of ex vivo-manipulated grafts.(Blood, 2000;96:4185-4193) (C) 2000 by The American Society of Hematology.