Kurland J I, Meyers P A, Moore M A
J Exp Med. 1980 Apr 1;151(4):839-52. doi: 10.1084/jem.151.4.839.
We investigated the effects of murine resident peritoneal macrophages on the in vitro proliferation of erythropoietin (Ep)-sensitive committed precursors colony-forming unit-erythroid (CFU-E) and burst-forming unit-erythroid (BFU-E) with a two-layer cloning system of methylcellulose and semisolid agar. The addition of increasing numbers of macrophages to the agar underlayer resulted in a progressive increase in the numbers of both CFU-E and BFU-E that proliferated in the presence of Ep. CFU-E, but not BFU-E, proliferated to form colonies in the absence Qf exogenously added Ep, and this proliferation was enhanced in a dose-dependent fashion by the presence of macrophages in the underlayer. The enhancing effects of a given number of macrophages and a given concentration of Ep were greater than the sum of the individual effects of macrophages and Ep alone. This erythropoietic syngerism was more evident with BFU-E because burst formation was not seen in the absence of exogenously added Ep. Macrophage underlayers stimulated three to five times the number of erythroid bursts seen with Ep alone. Cell-free agar underlayers or agar underlayers prepared with nonadherent peritoneal cells or unseparated cells from thymus, lymph node, or spleen failed to augment Ep- dependent erythroid colony formation. No enhancement of CFU-E or BFU-E was demonstrable after depletion ofadherent cells from peritoneal cell suspensions by passage over columns of Sephadex G-10. Analysis by sedimentation velocity of peritoneal cells confirmed that the cells responsible for elaborating the erythroid-enhancing activity were macrophages on the basis of morphologic, histochemical, and functional criteria. Serum- free media conditioned by macrophages in the absence of Ep contained the erythroid-enhancing activities, which indicated that Ep was not required for the elaboration of these diffusible substances. These studies indicate that although macrophages are not obligate for the growth of erythroid precursors, they serve as an important source of diffusible factors that reduce the in vitro requirement for Ep.
我们使用甲基纤维素和半固体琼脂双层克隆系统，研究了小鼠常驻腹膜巨噬细胞对促红细胞生成素（Ep）敏感的定向祖细胞红系集落形成单位（CFU-E）和红系爆式集落形成单位（BFU-E）体外增殖的影响。在琼脂底层添加数量不断增加的巨噬细胞，导致在Ep存在的情况下增殖的CFU-E和BFU-E数量逐渐增加。CFU-E在没有外源添加Ep的情况下也能增殖形成集落，但BFU-E不能，并且底层巨噬细胞的存在以剂量依赖方式增强了这种增殖。给定数量的巨噬细胞和给定浓度的Ep的增强作用大于单独的巨噬细胞和Ep的个体作用之和。这种红细胞生成协同作用在BFU-E中更明显，因为在没有外源添加Ep的情况下看不到爆式形成。巨噬细胞底层刺激产生的红系爆式数量是单独使用Ep时的三到五倍。无细胞琼脂底层或用非黏附性腹膜细胞或来自胸腺、淋巴结或脾脏的未分离细胞制备的琼脂底层，未能增强依赖Ep的红系集落形成。通过Sephadex G-10柱对腹膜细胞悬液进行传代以耗尽黏附细胞后，未证实CFU-E或BFU-E有增强作用。通过腹膜细胞沉降速度分析证实，根据形态学、组织化学和功能标准，负责产生红系增强活性的细胞是巨噬细胞。在没有Ep的情况下，巨噬细胞条件培养基含有红系增强活性，这表明产生这些可扩散物质不需要Ep。这些研究表明，虽然巨噬细胞不是红系前体细胞生长所必需的，但它们是可扩散因子的重要来源，可降低体外对Ep的需求。
