Bioactive proteinase 3 on the cell surface of human neutrophils: Quantification, catalytic activity, and susceptibility to inhibition
Bioactive proteinase 3 on the cell surface of human neutrophils: Quantification, catalytic activity, and susceptibility to inhibition
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DOI：
10.4049/jimmunol.165.6.3366
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发表时间：
2000-09-15
影响因子：
4.4
通讯作者：
Owen, CA
中科院分区：
文献类型：
--
作者：
Campbell, EJ;Campbell, MA;Owen, CA
尽管蛋白水解酶3(Protease3，PR3)具有促进炎症和损伤组织的潜在作用，但其在健康供者的中性粒细胞(PMN)中的生物学形式和功能却鲜有人关注。在本文中，我们发现PMN每个细胞含有3.24+/-SD 0.24pg的PR3，PMN的嗜天青颗粒中PR3的平均浓度为13.4 mM，在未刺激的PMN的细胞表面可检测到低水平的PR3，单用细胞因子或化学诱导剂暴露于PMN可诱导细胞表面结合PR3的轻度增加(1.5-2.5倍)，相反，用细胞因子短暂地启动PMN，然后用化学诱导剂激活，诱导细胞表面PR3的快速而持久的增加，同时引起细胞表面PR3的最小自由释放，膜结合的Pr3对Boc-Alanine-Alanine-Norvaline-硫代苯甲酸酯和纤维连接蛋白具有催化活性，但与可溶性Pr3相反，膜结合的Pr3不受生理性酶抑制剂的抑制。PR3似乎通过电荷依赖的机制结合到PMN的细胞表面，因为固定的、活化的PMN暴露在离子强度增加的溶液中会导致PR3、HLE和CG的洗脱，并且它们的洗脱顺序和它们的等电点之间有直接的关系。这些数据表明，PMN细胞表面表达的PR3是一种重要的生物活性形式，如果PMN细胞表面的PR3表达失调，则可以直接放大组织损伤，也可以通过产生自身抗体间接放大组织损伤。
Although proteinase 3 (PR3) is known to have the potential to promote inflammation and injure tissues, the biologic forms and function of PR3 in polymorphonuclear neutrophils (PMN) from healthy donors have received little attention. In this paper, we show that PMN contain 3.24 +/- SD 0.24 pg of PR3 per cell, and that the mean concentration of PR3 in azurophil granules of PMN is 13.4 mM, Low levels of PR3 are detectable on the cell surface of unstimulated PMN, Exposure of PMN to cytokines or chemoattractants alone induces modest (1.5- to 2.5-fold) increases in cell surface-bound PR3, In contrast, brief priming of PMN with cytokines, followed by activation with a chemoattractant, induces rapid and persistent, 5- to 6-fold increases in cell surface expression of PR3, while causing minimal free release of PR3, Membrane-bound PR3 on PMN is catalytically active against Boc-Alanine-Alanine-Norvaline-thiobenzyl ester and fibronectin, but in marked contrast to soluble PR3, membrane-bound PR3 is resistant to inhibition by physiologic proteinase inhibitors. PR3 appears to bind to the cell surface of PMN via a charge-dependent mechanism because exposure of fixed, activated PMN to solutions having increasing ionic strength results in elution of PR3, HLE, and CG, and there is a direct relationship between their order of elution and their isoelectric points. These data indicate that rapidly inducible PR3 expressed on the cell surface of PMN is an important bioactive form of the proteinase, If PR3 expression on the cell surface of PMN is dysregulated, it is well equipped to amplify tissue injury directly, and also indirectly via the generation of autoantibodies.