Henkel G W, McKercher S R, Leenen P J, Maki R A
The Burnham Institute, La Jolla, CA, and Department of Immunology, Erasmus University, Rotterdam, The Netherlands.
Blood. 1999 May 1;93(9):2849-58.
Mice homozygous for the disruption of the PU.1 (Spi-1) gene do not produce mature macrophages. In determining the role of PU.1 in macrophage differentiation, the present study investigated whether or not there was commitment to the monocytic lineage in the absence of PU.1. Early PU.1-/- myeloid colonies were generated from neonate liver under conditions that promote primarily macrophage and granulocyte/macrophage colonies. These PU.1-/- colonies were found to contain cells with monocytic characteristics as determined by nonspecific esterase stain and the use of monoclonal antibodies that recognize early monocyte precursors, including Moma-2, ER-MP12, ER-MP20, and ER-MP58. In addition, early myeloid cells could be grown from PU.1-/- fetal liver cultures in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF). Similar to the PU.1 null colonies, the GM-CSF-dependent cells also possessed early monocytic characteristics, including the ability to phagocytize latex beads. The ability of PU.1-/- progenitors to commit to the monocytic lineage was also verified in vivo by flow cytometry and cytochemical analysis of primary neonate liver cells. The combined data shows that PU.1 is absolutely required for macrophage development after commitment to this lineage.
PU.1（Spi-1）基因破坏的纯合小鼠不产生成熟巨噬细胞。在确定PU.1在巨噬细胞分化中的作用时，本研究调查了在缺乏PU.1的情况下是否存在向单核细胞谱系的定向分化。在主要促进巨噬细胞和粒细胞/巨噬细胞集落形成的条件下，从新生小鼠肝脏中产生早期PU.1基因敲除的髓系集落。通过非特异性酯酶染色以及使用识别早期单核细胞前体的单克隆抗体（包括Moma-2、ER-MP12、ER-MP20和ER-MP58），发现这些PU.1基因敲除的集落含有具有单核细胞特征的细胞。此外，在粒细胞-巨噬细胞集落刺激因子（GM-CSF）存在的情况下，早期髓系细胞可以从PU.1基因敲除的胎肝培养物中生长。与PU.1基因敲除的集落相似，依赖GM-CSF的细胞也具有早期单核细胞特征，包括吞噬乳胶珠的能力。通过对原代新生小鼠肝细胞进行流式细胞术和细胞化学分析，也在体内验证了PU.1基因敲除祖细胞向单核细胞谱系定向分化的能力。综合数据表明，在定向分化为该谱系后，巨噬细胞发育绝对需要PU.1。
