Williams N, Jackson H, Sheridan A P, Murphy M J, Elste A, Moore M A
Blood. 1978 Feb;51(2):245-55.
Megakaryocytes and their precursor cells were sustained in mouse bone marrow suspension cultures for over 4-6 wk. Megakaryocyte precursor cells were detected by their capacity to form colonies of megakaryocytes in semisolid agar cultures. Colony formation was dependent on the presence of medium conditioned by a myelomonocytic leukemic cell line (WEHI-3CM). Megakaryocytes from the liquid and semisolid cultures were identified by cytoplasmic acetylcholine esterase and by ultrastructural analysis. The suspension medium from the bone marrow liquid cultures which sustained megakaryopoiesis was not directly acitive in stimulating megakaryocyte colony formation in the semisolid agar cultures, but potentiated the number of colonies detected when WEHI-3CM was present. Bone marrow-conditioned medium increased the sensitivity of megakaryocyte progenitor cells to the stimulus in WEHI-3CM. Addition of the activities present in the two sources produced a quantitative assay for the detection of mouse megakaryocyte progenitor cells. These studies showed: (1) that no inductive regulator of in vitro clones of megakaryocytes was present in the supernatants from the long-term marrow cultures and, (2) that at least two factors were necessary for the induction of megakaryocyte progenitors to proliferate and differentiate in semisolid cultures in vitro.
巨核细胞及其前体细胞在小鼠骨髓悬浮培养物中维持了4至6周以上。巨核细胞前体细胞通过其在半固体琼脂培养物中形成巨核细胞集落的能力来检测。集落形成依赖于髓单核细胞白血病细胞系（WEHI - 3CM）条件培养基的存在。通过细胞质乙酰胆碱酯酶和超微结构分析鉴定来自液体和半固体培养物的巨核细胞。维持巨核细胞生成的骨髓液体培养物的悬浮培养基在刺激半固体琼脂培养物中的巨核细胞集落形成方面没有直接活性，但在存在WEHI - 3CM时会增加检测到的集落数量。骨髓条件培养基增加了巨核细胞祖细胞对WEHI - 3CM中刺激的敏感性。两种来源中存在的活性物质的添加产生了一种用于检测小鼠巨核细胞祖细胞的定量测定方法。这些研究表明：（1）长期骨髓培养物的上清液中不存在体外巨核细胞克隆的诱导调节因子，（2）在体外半固体培养中，至少需要两种因子来诱导巨核细胞祖细胞增殖和分化。
