Takezawa R, Watanabe Y, Akaike T
Department of Biomolecular Engineering, Tokyo Institute of Technology, Yokohama.
J Biochem. 1995 Dec;118(6):1175-83. doi: 10.1093/oxfordjournals.jbchem.a125004.
Controversy has surrounded origin and differentiation of tissue macrophages. We directly demonstrate the differentiation of bone marrow cells into macrophages in the liver in vivo using a cell-labeling fluorescence dye, PKH-26. Bone marrow cells labeled with PKH26 were intravenously injected into syngenic mice, and these cells were tracked by flow cytometric analysis. The majority of the labeled cells were detected only in the liver after 4 days. Interestingly, antigens specific for macrophage lineage cells (F4/80, Fc gamma RII, and CD14) were detected on the liver-accumulated cells only 4 h after the injection. The pattern of the antigen expression changed to that of Kupffer cells (F4/80+, Fc gamma RII+, Mac-1-) after 4 days and remained so thereafter. These labeled cells in the liver were esterase staining-positive and showed phagocytic activity at day 7. The number of labeled cells among the Kupffer cells in the liver increased with days after injection. This indicates that bone marrow cells accumulate in the liver and differentiate into liver macrophages on site. Roles of factors secreted from hepatocytes are also discussed.
组织巨噬细胞的起源和分化一直存在争议。我们使用细胞标记荧光染料PKH-26在体内直接证明了骨髓细胞在肝脏中分化为巨噬细胞。将用PKH26标记的骨髓细胞静脉注射到同基因小鼠体内，并通过流式细胞术分析追踪这些细胞。4天后，大多数标记细胞仅在肝脏中被检测到。有趣的是，注射后仅4小时，在肝脏聚集的细胞上就检测到了巨噬细胞系细胞特异性抗原（F4/80、FcγRII和CD14）。4天后，抗原表达模式变为库普弗细胞的模式（F4/80+、FcγRII+、Mac-1-），此后一直保持。肝脏中的这些标记细胞在第7天酯酶染色呈阳性，并表现出吞噬活性。肝脏库普弗细胞中标记细胞的数量随着注射后天数的增加而增加。这表明骨髓细胞在肝脏中聚集并在原位分化为肝脏巨噬细胞。还讨论了肝细胞分泌的因子的作用。
