Knobel K M, McNally M A, Berson A E, Rood D, Chen K, Kilinski L, Tran K, Okarma T B, Lebkowski J S
Applied Immune Sciences, Santa Clara, CA 95054-1114.
Exp Hematol. 1994 Dec;22(13):1227-35.
In this report, we evaluated the short-term expansion of murine bone marrow mononuclear cells (BMMNC) and enriched stem cell populations to determine the capacity of these cells for long-term rescue and engraftment to lethally irradiated recipients. In our study, nonadherent bone marrow mononuclear cell (NBM-MNC) and Thy1+Lin- stem cells populations were cultured with interleukin-3 (IL-3) or IL-3 plus stem cell factor (SCF) for periods up to 6 days. By day 6 of culture, the mononuclear cells (MNC) decreased to 6% of input cell number, whereas Thy1+Lin- cells increased by 2310%. Doses of 95,000; 100,000; 50,000; and 250,000 NBM-MNCs at 0, 1, 2, and 6 days of culture, respectively, rescued 50% of lethally irradiated mice. When 250,000 MNCs were cultured for 0, 1, 2, and 6 days, 71, 61, 100, and 50% of the animals survived lethal irradiation for greater than 24 weeks. In contrast, doses of 8,000 and 21,000 Thy1+Lin- cells cultured 0 and 1 day, respectively, yielded 50% survival rates. These same cells cultured for 6 days failed to rescue recipients even at high doses. Twenty thousand Thy1+Lin- cells cultured for 0, 1, 2, and 6 days, even in the presence of SCF, produced decreasing survival rates of 86, 43, 26, and 0%, respectively. The proliferative responses of these different populations in combination with their long-term rescue abilities indicated that the absolute number of long-term rescue units (LD50, 24 weeks) in the cultured Thy1+Lin- population decreased faster than in similarly cultured NBM-MNCs. Studies evaluating donor cell engraftment demonstrated that animals rescued with cultured Thy1+Lin- and NBM-MNCs maintained high levels of donor reconstitution [7]. The percent donor T cell engraftment did not significantly change between 2 and 17 months post-bone marrow transplantation (post-BMT). Therefore, those animals who received sufficient cells to survive lethal irradiation generally established and maintained high levels of donor engraftment. The data suggest a role for accessory cells and/or factors in the preservation of stem cell activity.
在本报告中，我们评估了小鼠骨髓单个核细胞（BMMNC）和富集的干细胞群体的短期扩增情况，以确定这些细胞对致死性照射受体进行长期挽救和植入的能力。在我们的研究中，将非贴壁骨髓单个核细胞（NBM-MNC）和Thy1+Lin-干细胞群体与白细胞介素-3（IL-3）或IL-3加干细胞因子（SCF）一起培养长达6天。培养至第6天时，单个核细胞（MNC）减少至输入细胞数的6%，而Thy1+Lin-细胞增加了2310%。分别在培养的第0、1、2和6天给予95,000、100,000、50,000和250,000个NBM-MNC，挽救了50%的致死性照射小鼠。当250,000个MNC分别培养0、1、2和6天时，71%、61%、100%和50%的动物在致死性照射后存活超过24周。相比之下，分别在培养0天和1天的8,000个和21,000个Thy1+Lin-细胞，存活率为50%。即使在高剂量下，这些相同的细胞培养6天也未能挽救受体。即使在存在SCF的情况下，分别在培养0、1、2和6天的20,000个Thy1+Lin-细胞的存活率分别为86%、43%、26%和0%，呈下降趋势。这些不同群体的增殖反应及其长期挽救能力表明，培养的Thy1+Lin-群体中长期挽救单位（LD50，24周）的绝对数量比同样培养的NBM-MNC下降得更快。评估供体细胞植入的研究表明，用培养的Thy1+Lin-和NBM-MNC挽救的动物维持了高水平的供体重建[7]。骨髓移植（BMT）后2至17个月期间，供体T细胞植入百分比没有显著变化。因此，那些接受足够细胞以在致死性照射后存活的动物通常建立并维持了高水平的供体植入。数据表明辅助细胞和/或因子在干细胞活性的保存中起作用。
