REGULATION OF CELL-SURFACE APO-1/FAS (CD95) LIGAND EXPRESSION BY METALLOPROTEASES
REGULATION OF CELL-SURFACE APO-1/FAS (CD95) LIGAND EXPRESSION BY METALLOPROTEASES
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DOI：
10.1002/eji.1830250828
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发表时间：
1995-08-01
影响因子：
5.4
通讯作者：
KRAMMER, PH
中科院分区：
文献类型：
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作者：
MARIANI, SM;MATIBA, B;KRAMMER, PH
APO-1/Fas（CD 95）配体（APO-1 L）诱导敏感靶细胞凋亡。APO-1 L介导穿孔素基因敲除小鼠活化诱导的T细胞死亡和Ca 2+非依赖性细胞毒性为了确定APO-1 L是否在活化的T细胞表面表达，并研究导致可溶性形式释放的机制，我们开发了兔抗APO-IL抗体（Ab）。纯化的兔Ab检测到约42和40 kDa的人和小鼠APO-1 L的成熟形式。此外，Ab识别约32-33 kDa的非糖基化形式的APO-1 L。在活化的人T细胞中，可检测到可溶形式的APO-1 L，分子量为26 kDa。三个人T淋巴母细胞系的免疫荧光显示，这些细胞的激活佛波醇12-肉豆蔻酸酯13-乙酸酯/离子霉素诱导细胞表面载脂蛋白-1 L的显着增加，只有在金属蛋白酶抑制剂的存在下。Zn 2+，但不是Ca 2+，防止在1，10-菲咯啉的存在下观察到的表面APO-1 L的增加。阻断其他类型的蛋白酶（丝氨酸和酸性蛋白酶，胰凝乳蛋白酶）没有影响。金属蛋白酶抑制剂增加的表面载脂蛋白-1 L的表达不依赖于T细胞活化，因为金属蛋白酶抑制剂也调制组成型载脂蛋白-1 L表达的低水平。这些结果表明，人APO-1 L的细胞表面表达受Zn 2+依赖性金属蛋白酶的调节。表面APO-1 L的裂解可能作为一种调节机制，以防止膜结合形式的蓄积，并可能导致APO-1 L的全身效应。
APO-1/Fas (CD95) ligand (APO-1L) induces apoptosis in sensitive target cells. Activation-induced T cell death and Ca2+-independent cytotoxicity in perforin knockout mice are mediated by APO-1L. To define whether APO-1L is expressed on the surface of activated T cells and to investigate the mechanisms leading to the release of a soluble form, we developed rabbit anti-APO-IL antibodies (Ab). The purified rabbit Ab detected the mature forms of the human and mouse APO-1L of approximately 42 and 40 kDa. In addition, the Ab recognized the non-glycosylated form of APO-1L of approximately 32-33 kDa. In activated human T cells, the soluble form of APO-1L was detectable with a moleculas mass of 26 kDa. Immunofluorescence of three human T lymphoblastoid cell lines showed that activation of these cells by phorbol 12-myristate 13-acetate/ionomycin induced a significant increase in cell surface APO-1L only in the presence of metalloprotease inhibitors. Zn2+, but not Ca2+, prevented the increase in surface APO-1L observed in the presence of 1,10-phenanthroline. Blocking of other classes of proteases (serine- and acid-proteases, chymotrypsin) had no effect. Increased expression of surface APO-1L by metalloprotease inhibitors was not dependent on T cell activation, as the metalloprotease inhibitors also modulated the low level of constitutive APO-1L expression. These results suggest that cell surface expression of human APO-1L is regulated by Zn2+-dependent metalloproteases. Cleavage of surface APO-1L may act as a regulatory mechanism to prevent accumulation of the membrane-bound form and may cause systemic effects of the APO-1L.