Characterization of interferon-alpha binding sites on human cell lines.
Characterization of interferon-alpha binding sites on human cell lines.
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人类细胞系上干扰素-α 结合位点的表征。
DOI：
10.1089/jir.1988.8.803
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发表时间：
1988
期刊：
影响因子：
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通讯作者：
Pfeffer,LM
中科院分区：
文献类型：
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作者：
VandenBroecke,C;Pfeffer,LM
人干扰素-α的结合部位已在人淋巴母细胞样细胞、黑色素瘤、横纹肌肉瘤和宫颈癌细胞上得到鉴定。碘化重组干扰素α-Con1是已知的干扰素-α亚型的类似物，用琥珀酸二丁二亚胺在细胞表面产生4个118kD、138kD、159kD和260kD的干扰素受体复合体，与干扰素-α特异性结合。由于干扰素-α在溶液中以单体、二聚体和三聚体的形式存在，且三种低分子干扰素-α受体复合体的分子量不同，提示100kD的人干扰素-α受体结合了不止一个分子的干扰素-α。260kD的高分子量复合体可能是受体二聚化的结果。在不与干扰素-α特异性结合的横纹肌肉瘤亚克隆中，没有观察到这些复合体。用胰酶对细胞进行预处理，可消除这些复合体的形成。神经氨酸酶处理细胞不会减少干扰素-α的结合，但增加了四种干扰素-α-受体复合体的电泳率。其他糖苷酶(即甘露糖苷酶、β-半乳糖苷酶和内切糖苷酶F)对干扰素-α结合或复合体的迁移率没有影响。因此，尽管干扰素-α受体是一种糖蛋白，但糖基化部分显然不是干扰素-αα结合域的一部分。干扰素-α-受体复合体的形成与与干扰素的孵育时间无关(在15℃下孵育5分钟至1小时)。对干扰素-α的抗增殖作用敏感(Cl-1)或抵抗(Cl2-)的丹迪淋巴母细胞亚克隆与干扰素-α的结合能力相似。与敏感的氯-1细胞相比，耐药的氯-2细胞中干扰素受体复合体与Triton不溶细胞骨架基质的结合明显减弱。然而，干扰素受体复合体，包括那些与细胞骨架非共价相关的复合体，在敏感和耐药的亚克隆中结构相似。因此，结合后缺陷可能是Cl-2细胞对干扰素-α的抗增殖作用产生抵抗的原因。
The binding sites for human interferon-α (IFN-α) have been characterized on human lymphoblastoid, melanoma, rhabdomyosarcoma, and cervical carcinoma cells. Crosslinking of iodinated-recombinant DNA-derived IFN-α-Con1, an analog of the known IFN-α subtypes, to the cell surface with disuccinimidyl suberate yielded four IFN-receptor complexes of 118, 138, 159, and 260 kD on all cell lines that specifically bind IFN-α. Since IFN-α exists in solution as monomers, dimers, and trimers, and the three lower molecular weight IFN-α—receptor complexes differ by the molecular weight of IFN-α (20 kD), this suggests that the human IFN-α receptor of 100 kD binds more than one molecule of IFN-α. The higher molecular weight complex of 260 kD may result from dimerization of the receptor. None of these complexes was observed in a rhabdomyosarcoma subclone that does not specifically bind IFN-α. Pretreatment of cells with trypsin abolished the formation of these complexes. Pretreatment of cells with neuraminidase did not reduce IFN-α binding, but increased the electrophoretic mobility of all four IFN-α-receptor complexes. Other glycosidases (i.e., mannosidase, β-galactosidase, and endoglycosidase F) had no effects on IFN-α binding or mobility of complexes. Thus, although the IFN-α receptor is a glycoprotein, the glycosylated portion is apparently not part of the IFN-aα-binding domain. The formation of IFN-α—receptor complexes is independent of the duration of incubation with IFN (from 5 min to 1 h at 15°C). Subclones of Dandi lymphoblastoid cells that are sensitive (Cl-1) or resistant (Cl-2) to the antiproliferative effect of IFN-α have similar IFN-α binding capacity. The association of the IFN—receptor complexes with Triton-insoluble cytoskeletal matrix is markedly diminished in resistant Cl-2 cells relative to that in sensitive Cl-1 cells. However, IFN—receptor complexes, including those noncovalently associated with the cytoskeleton, are structurally similar in sensitive and resistant subclones. Thus, a post-binding defect may be responsible for the resistance of Cl-2 cells to the antiproliferative effect of IFN-α.