Schofield R
Blood Cells. 1978;4(1-2):7-25.
Several experimental findings that are inconsistent with the view that the spleen colony-forming cell (CFU-S) is the primary haemopoietic stem cell are reviewed. Recovery of CFU-S, both quantitatively and qualitatively, can proceed differently depending upon the cytotoxic agent or regime used to bring about the depletion. The virtual immortality of the stem cell population is at variance with evidence that the CFU-S population has an 'age-structure' which has been invoked by several workers to explain experimental and clinical observations. To account for these inconsistencies, a hypothesis is proposed in which the stem cell is seen in association with other cells which determine its behaviour. It becomes essentially a fixed tissue cell. Its maturation is prevented and, as a result, its continued proliferation as a stem cell is assured. Its progeny, unless they can occupy a similar stem cell 'niche', are first generation colony-forming cells, which proliferate and mature to acquire a high probability of differentiation, i.e., they have an age-structure. Some of the experimental situations reviewed are discussed in relation to the proposed hypothesis.
本文综述了一些实验结果，这些结果与脾集落形成细胞（CFU-S）是主要造血干细胞这一观点不一致。CFU-S数量和质量的恢复情况，会因用于造成细胞耗竭的细胞毒性药物或方案的不同而有所差异。干细胞群体的近乎永生与CFU-S群体具有“年龄结构”这一证据相矛盾，有几位研究者援引这种“年龄结构”来解释实验和临床观察结果。为了解释这些不一致之处，本文提出了一个假说，即干细胞与其他决定其行为的细胞相关联。它本质上成为了一种固定组织细胞。其成熟过程受到抑制，因此能确保其作为干细胞持续增殖。其后代，除非能占据类似的干细胞“龛位”，否则就是第一代集落形成细胞，它们会增殖并成熟，从而获得较高的分化概率，也就是说，它们具有年龄结构。文中结合所提出的假说，对所综述的一些实验情况进行了讨论。
