Chapuis F, Rosenzwajg M, Yagello M, Ekman M, Biberfeld P, Gluckman J C
Laboratoire de Biologie et Génétique des Déficits Immunitaires, Faculté de Médecine, Hôpital de la Pitié-Salpêtrière, Paris, France.
Eur J Immunol. 1997 Feb;27(2):431-41. doi: 10.1002/eji.1830270213.
Since either macrophages (Mphi) or dendritic cells (DC) differentiate from monocytes (MO) depending on culture conditions, we investigated the relationship of the DC and Mphi differentiation pathways. Culturing MO-enriched blood mononuclear cells with Mphi colony-stimulating factor (M-CSF) or with granulocyte/Mphi (GM)-CSF induced Mphi with a different morphology and CD14/CD1a expression. In contrast, in cultures with GM-CSF and interleukin (IL)-4, cells rapidly became nonadherent and acquired DC morphology, ultrastructure, CD1a expression, and most DC markers; they lost membrane CD14 and CD64 and capacity of phagocytosis, displayed less CD68 than Mphi, but retained nonspecific esterase activity. These DC directly developed from MO without proliferation inasmuch as only day 0 FACS-sorted MO, but not small CD14- cells, differentiated into DC when cultured with GM-CSF and IL-4, or to Mphi with M-CSF While overall cell numbers declined, DC numbers plateaued from culture day 2 onwards, indicating that most had differentiasted by then. This differentiation was radioresistant and occurred without [3H]thymidine incorporation. Commitment to differentiate into DC with GM-CSF and IL-4 was irreversible by day 2, since discontinuing IL-4 at this point did not revert cells to Mphi. Alternatively, cells rapidly converted to DC when IL-4 was added from day 2 to cultures initiated with GM-CSF only. If cultures were initiated with M-CSF and switched to GM-CSF and IL-4 after 2 or 5 days, about half of the cells still converted to DC. Thus, the capacity of MO and even of Mphi to differentiate into DC was conserved for at least this period. The increased capacity to stimulate the mixed leukocyte reaction correlated with the relative number of CD1a+ cells at any time and under each condition tested, a confirmation that these cells functionally qualify as DC. Thus, MO and even Mphi can be directed to differentiate into DC depending on the cytokine microenvironment.
由于巨噬细胞（Mphi）或树突状细胞（DC）会根据培养条件从单核细胞（MO）分化而来，我们研究了DC和Mphi分化途径之间的关系。用巨噬细胞集落刺激因子（M-CSF）或粒细胞/巨噬细胞（GM）-CSF培养富含MO的血液单核细胞，可诱导出具有不同形态以及CD14/CD1a表达的Mphi。相比之下，在含有GM-CSF和白细胞介素（IL）-4的培养物中，细胞迅速变得不黏附，并获得了DC的形态、超微结构、CD1a表达以及大多数DC标志物；它们失去了膜CD14和CD64以及吞噬能力，与Mphi相比，CD68表达较少，但保留了非特异性酯酶活性。这些DC直接从MO发育而来，没有增殖，因为只有第0天经荧光激活细胞分选术（FACS）分选的MO，而不是小的CD14阴性细胞，在用GM-CSF和IL-4培养时可分化为DC，用M-CSF培养则分化为Mphi。虽然总体细胞数量下降，但DC数量从培养第2天起趋于平稳，这表明到那时大多数细胞已经分化。这种分化对辐射有抗性，且在没有[3H]胸腺嘧啶核苷掺入情况下发生。到第2天，用GM-CSF和IL-4分化为DC的过程就不可逆转了，因为此时停止IL-4并不会使细胞恢复为Mphi。或者，当从第2天开始向仅用GM-CSF起始的培养物中添加IL-时，细胞会迅速转变为DC。如果培养物先用M-CSF起始，然后在2天或5天后换成GM-CSF和IL-4，大约一半的细胞仍会转变为DC。因此，至少在这段时间内，MO甚至Mphi分化为DC的能力得以保留。在任何时间以及每种测试条件下，刺激混合淋巴细胞反应的能力增强与CD1a阳性细胞的相对数量相关，这证实了这些细胞在功能上符合DC的特征。因此，根据细胞因子微环境，MO甚至Mphi都可以被诱导分化为DC。
