Distribution of decay-accelerating factor in the peripheral blood of normal individuals and patients with paroxysmal nocturnal hemoglobinuria.
Distribution of decay-accelerating factor in the peripheral blood of normal individuals and patients with paroxysmal nocturnal hemoglobinuria.
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正常个体和阵发性夜间血红蛋白尿症患者外周血中衰减加速因子的分布。
DOI：
10.1084/jem.162.1.75
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发表时间：
1985-07-01
影响因子：
15.3
通讯作者：
Nussenzweig, V
中科院分区：
文献类型：
--
作者：
Kinoshita, T;Medof, M E;Silber, R;Nussenzweig, V
衰变加速因子（Decay-Accelerating Factor，缩写为ERF）是一种从红细胞膜中分离出来的70，000 Mr蛋白质。其功能是抑制补体级联放大酶在细胞表面的组装，从而保护它们免受自体补体的损伤。我们提出了单克隆抗体，以研究其分布在正常人和阵发性睡眠性血红蛋白尿症（PNH），一种疾病的特点是不寻常的敏感性红细胞的溶血活性的补体患者的外周血细胞。免疫放射分析和荧光激活细胞分选仪分析的结果表明，红细胞不仅存在，但广泛分布在血小板，中性粒细胞，单核细胞，和B和T淋巴细胞的表面膜。通过蛋白质印迹法，我们观察到小但一致的差异，从不同类型的细胞膜的Mrs 25。定量研究表明，吞噬细胞和B淋巴细胞可能更频繁地与免疫复合物和其他潜在的补体激活剂接触，它们具有最高的补体水平。正如其他人以前报道的那样，PNH患者的红细胞是缺乏的。当患者的红细胞在酸化血清中孵育（Ham试验）时，只有DAF缺陷细胞溶解。此外，我们检测到血小板和所有类型的白细胞上的CD 4+表达缺陷。在这些患者中观察到的PNH缺陷模式与PNH细胞是单克隆起源的概念一致。在一名患者中，异常和正常细胞仅见于红系、髓系和巨核细胞系。在另外两名患者中，淋巴细胞也是β缺陷的，这表明全能干细胞发生了突变。因此，看来导致PNH的病变可发生在造血细胞分化的不同阶段。
Decay-accelerating factor (DAF) is a 70,000 Mr protein that has been isolated from the membrane of red cells. The function of DAF is to inhibit the assembly of amplifying enzymes of the complement cascade on the cell surface, thereby protecting them from damage by autologous complement. We raised monoclonal antibodies to DAF and used them to study its distribution in cells from the peripheral blood of normal individuals and of patients with paroxysmal nocturnal hemoglobinuria (PNH), a disease characterized by the unusual susceptibility of red cells to the hemolytic activity of complement. The results of immunoradiometric assays and of fluorescence-activated cell sorter analysis showed that DAF was present not only on red cells but was widely distributed on the surface membrane of platelets, neutrophils, monocytes, and B and T lymphocytes. By Western blotting, we observed small but consistent differences in the Mr of DAF from the membranes of various cell types. Quantitative studies showed that phagocytes and B lymphocytes, which presumably enter more frequently in contact with immune complexes and other potential activators of complement, had the highest DAF levels. As previously reported by others, the red cells from PNH patients were DAF deficient. When the patients' red cells were incubated in acidified serum (Ham test), only the DAF-deficient cells were lysed. In addition, we detected defects in DAF expression on platelets and all types of leukocytes. The observed patterns of DAF deficiency in these patients were consistent with the concept that the PNH cells were of monoclonal origin. In one patient, abnormal and normal cells were found only in the erythroid, myeloid, and megakaryocytic lineages. In two other patients, the lymphocytes were also DAF deficient, suggesting that a mutation occurred in a totipotent stem cell. It appears, therefore, that the lesion leading to PNH can occur at various stages in the differentiation of hematopoietic cells.