Human recombinant soluble decay accelerating factor inhibits complement activation in vitro and in vivo.
Human recombinant soluble decay accelerating factor inhibits complement activation in vitro and in vivo.
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人重组可溶性衰变加速因子在体外和体内抑制补体激活。
DOI：
10.4049/jimmunol.149.5.1736
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发表时间：
1992
影响因子：
4.4
通讯作者：
I. Caras
中科院分区：
文献类型：
--
作者：
P. Moran;H. Beasley;A. Gorrell;E. Martin;P. Gribling;H. Fuchs;N. Gillett;L. Burton;I. Caras
补体在激活炎症反应中发挥作用，并参与一些炎症性疾病的发病机制。为了控制不需要的 C 激活，我们评估了 C 调节剂，即人类腐烂加速因子 (DAF)。从转染的中国仓鼠卵巢细胞中纯化出三种形式的重组DAF：从细胞膜中提取的糖磷脂酰肌醇（GPI）连接的膜DAF（mDAF）；自发脱落源自 mDAF 的可溶性 DAF (sDAF)；以及一种新的分泌蛋白 (seDAF)，是通过删除 GPI 附着信号而产生的。我们发现所有三种分子均抑制 C 激活的经典途径和替代途径。以下观察结果表明，从中国仓鼠卵巢细胞中提取的 mDAF 通过其 GPI 锚重新融入红细胞膜：1）用 mDAF 预孵育然后洗涤的细胞仍能完全免受 C 介导的溶血作用； 2) 与磷脂酰肌醇特异性磷脂酶 C 一起孵育可消除这种保护； 3) sDAF 和 seDAF 缺乏 GPI 锚，不与细胞膜结合。 mDAF 是比 sDAF 或 seDAF 更有效的 C 介导的溶血抑制剂，表明掺入细胞膜可大大提高 DAF 抑制细胞表面 C 活化的效率。相反，液相中的 C 激活被 sDAF 和 seDAF 抑制，但不被 mDAF 抑制，这可能是由于血清脂蛋白的干扰。使用豚鼠中的反向被动 Arthus 反应来评估重组 seDAF 体内抑制 C 激活的能力。根据大体和组织学检查判断，当在真皮部位施用时，seDAF 降低了由逆转的被动阿图斯反应诱导的免疫复合物介导的炎症反应的严重程度。这些数据表明 seDAF 可用作抗炎治疗剂。
Complement plays a role in activating the inflammatory response and has been implicated in the pathogenesis of some inflammatory diseases. With a view toward controlling unwanted C activation, we evaluated the C regulator, human decay accelerating factor (DAF). Three forms of recombinant DAF were purified from transfected Chinese hamster ovary cells: glycophosphatidylinositol (GPI)-linked membrane DAF (mDAF) extracted from cell membranes; spontaneously shed soluble DAF (sDAF) derived from mDAF; and a novel secreted protein (seDAF), generated by deletion of the signal for GPI attachment. We show that all three molecules inhibit both the classical and alternative pathways of C activation. The following observations indicate that mDAF extracted from Chinese hamster ovary cells reincorporates into RBC membranes via its GPI anchor: 1) cells that are preincubated with mDAF and then washed remain fully protected from C-mediated hemolysis; 2) incubation with phosphatidylinositol-specific phospholipase C abolishes this protection; and 3) sDAF and seDAF, which lack a GPI anchor, do not associate with cell membranes. mDAF is a more potent inhibitor of C-mediated hemolysis than either sDAF or seDAF, suggesting that incorporation into cell membranes greatly enhances the efficiency with which DAF inhibits C activation on the cell surface. In contrast, C activation in the fluid phase is inhibited by sDAF and seDAF, but not by mDAF, possibly due to interference by serum lipoproteins. A reversed passive Arthus reaction in guinea pigs was used to evaluate the ability of recombinant seDAF to inhibit C activation in vivo. When administered at dermal sites, seDAF reduced the severity of immune complex-mediated inflammatory reactions induced by a reversed passive Arthus reaction, as judged by both gross and histologic examination. These data indicate that seDAF may be useful as an anti-inflammatory therapeutic.