Cashman J, Eaves A C, Eaves C J
Blood. 1985 Oct;66(4):1002-5.
We have examined the cycling status of various classes of erythroid and granulopoietic progenitor populations maintained for many weeks in standard normal long-term human marrow cultures. These were initiated with a single inoculum of marrow aspirate and were routinely fed by weekly removal of half of the nonadherent cells and replacement of half of the growth medium. Progenitors of large erythroid colonies (more than eight erythroblast clusters) present in the nonadherent fraction and progenitors of small granulocyte/macrophage colonies (fewer than 500 cells) present in both the nonadherent and adherent fractions were found to be actively cycling at all times examined (28% to 63% kill following a 20-minute exposure to 20 microCi/mL of high specific activity 3H-thymidine). In contrast, progenitors of large granulocyte/macrophage colonies (more than 500 cells) and progenitors of large erythroid colonies (more than eight erythroblast clusters), present in the adherent layer, consistently alternated between a quiescent state at the time of each weekly medium change and a proliferating state two to three days later (0% to 13% kill and 21% to 49% kill, respectively). Additional experiments revealed that the activation of primitive progenitors in the adherent layer was not dependent on the addition of fresh glutamine or hydrocortisone, nor on the physical manipulations involved in changing the growth medium. These studies provide the first direct evidence that normal long-term human marrow cultures support the continued turnover of a variety of early hematopoietic progenitor cell types. Further, they indicate that the proliferative activity of the most primitive of these progenitors is regulated by stage-specific cell-cell interactions that are subject to manipulation.
我们已经检测了在标准正常长期人类骨髓培养物中维持数周的各类红系和粒系祖细胞群体的循环状态。这些培养物由单次接种的骨髓抽吸物起始，常规操作是每周去除一半非贴壁细胞并更换一半生长培养基。我们发现，非贴壁部分中存在的大型红系集落（超过8个成红细胞簇）的祖细胞以及非贴壁和贴壁部分中存在的小型粒细胞/巨噬细胞集落（少于500个细胞）的祖细胞，在所有检测时间点均处于活跃循环状态（暴露于20微居里/毫升高比活度³H-胸腺嘧啶20分钟后，杀伤率为28%至63%）。相比之下，贴壁层中存在的大型粒细胞/巨噬细胞集落（超过500个细胞）的祖细胞和大型红系集落（超过8个成红细胞簇）的祖细胞，在每次每周更换培养基时处于静止状态，而在两到三天后进入增殖状态，且呈现出一致的交替变化（杀伤率分别为0%至13%和21%至49%）。额外的实验表明，贴壁层中原始祖细胞的激活不依赖于添加新鲜谷氨酰胺或氢化可的松，也不依赖于更换生长培养基所涉及的物理操作。这些研究提供了首个直接证据，证明正常长期人类骨髓培养物支持多种早期造血祖细胞类型的持续更新。此外还表明，这些祖细胞中最原始的祖细胞的增殖活性受特定阶段的细胞间相互作用调节，而这种相互作用是可以操控的。
