Peters S O, Kittler E L, Ramshaw H S, Quesenberry P J
University of Massachusetts Cancer Center, Worcester 01605, USA.
Blood. 1996 Jan 1;87(1):30-7.
In vitro incubation of bone marrow cells with cytokines has been used as an approach to expand stem cells and to facilitate retroviral integration. Expansion of hematopoietic progenitor cells has been monitored by different in vitro assays and in a few instances by in vivo marrow renewal in myeloablated hosts. This is the first report of studies, using two competitive transplant models, in which cytokine-treated cells, obtained from nonpretreated donors (eg, 5-fluorouracil), were competed with normal cells. A basic assumption is that the expansion of progenitors assayed in vitro as high- and low-proliferative potential colony-forming cells (HPP- and LPP-CFCs) indicates an expansion of stem cells which will repopulate in vivo. This study shows that culture of marrow cells with four cytokines (stem cell factor, interleukin-3 [IL-3], IL-6, IL-11) induces significant expansion and proliferation of HPP-CFC and LPP-CFC. Cell-cycle analysis showed that these hematopoietic progenitors were induced to actively cell cycle by culture with these cytokines. In the first competitive transplant model, which uses Ly5.2/Ly5.1 congenic mice, cytokine-cultured Ly5.2 cells competed with noncultured Ly5.1 cells led to 5% +/- 1% engraftment at 12 weeks and to 4% +/- 2% engraftment at 22 weeks posttransplantation for the cytokine exposed cells. Noncultured Ly5.2 cells competed with cultured Ly5.1 cells led to 70% +/- 1% engraftment at 12 weeks and to 93% +/- 2% engraftment at 22 weeks posttransplantation. In the second model, which uses BALB/c marrow of opposite genders, cultured male cells lead to 13% +/- 9% engraftment at 10 weeks and 2% +/- 1% engraftment at 14 weeks posttransplantation; noncultured male cells lead to 70% +/- 2% and 95% +/- 2% engraftment at 10 and 14 weeks posttransplantation, respectively. Data presented here from two different competitive transplant studies show a defect of cytokine expanded marrow related to cell cycle activation which manifests as defective long-term repopulating capability in irradiated host mice. The engraftment defect is more profound at longer time intervals, suggesting that the most striking effect may be on long-term repopulating cells.
将骨髓细胞与细胞因子进行体外培养，已被用作一种扩增干细胞并促进逆转录病毒整合的方法。造血祖细胞的扩增已通过不同的体外试验进行监测，在少数情况下，还通过对经骨髓消融的宿主进行体内骨髓更新来监测。这是首份使用两种竞争性移植模型进行研究的报告，在这些模型中，将从未经预处理的供体（如5-氟尿嘧啶）获得的经细胞因子处理的细胞与正常细胞进行竞争。一个基本假设是，体外检测到的高增殖潜能集落形成细胞（HPP-CFC）和低增殖潜能集落形成细胞（LPP-CFC）中祖细胞的扩增表明了能够在体内重新填充的干细胞的扩增。本研究表明，用四种细胞因子（干细胞因子、白细胞介素-3 [IL-3]、IL-6、IL-11）培养骨髓细胞可诱导HPP-CFC和LPP-CFC显著扩增和增殖。细胞周期分析表明，这些造血祖细胞通过与这些细胞因子培养而被诱导进入活跃的细胞周期。在第一个竞争性移植模型中，使用Ly5.2/Ly5.1同源基因小鼠，经细胞因子培养的Ly5.2细胞与未培养的Ly5.1细胞竞争，在移植后12周导致5%±1%的植入，在22周导致4%±2%的植入。未培养的Ly5.2细胞与培养的Ly5.1细胞竞争，在移植后12周导致70%±1%的植入，在22周导致93%±2%的植入。在第二个模型中，使用不同性别的BALB/c骨髓，培养的雄性细胞在移植后10周导致13%±9%的植入，在14周导致2%±1%的植入；未培养的雄性细胞在移植后10周和14周分别导致70%±2%和95%±2%的植入。这里来自两项不同竞争性移植研究的数据表明，与细胞周期激活相关的细胞因子扩增骨髓存在缺陷，这表现为受辐照宿主小鼠中长期重新填充能力的缺陷。植入缺陷在较长时间间隔时更为明显，这表明最显著的影响可能是对长期重新填充细胞的影响。
