Interaction of antibodies to proteinase 3 (classic anti-neutrophil cytoplasmic antibody) with human renal tubular epithelial cells: Impact on signaling events and inflammatory mediator generation
Interaction of antibodies to proteinase 3 (classic anti-neutrophil cytoplasmic antibody) with human renal tubular epithelial cells: Impact on signaling events and inflammatory mediator generation
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DOI：
10.4049/jimmunol.168.6.3057
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发表时间：
2002-03-15
影响因子：
4.4
通讯作者：
Sibelius, U
中科院分区：
文献类型：
--
作者：
Hattar, K;Grandel, U;Sibelius, U
在抗中性粒细胞胞浆抗体（ANCA）中，靶向蛋白酶3（PR 3）的ANCA对韦格纳肉芽肿病（WG）具有较高的敏感性和特异性。这些自身抗体的致病作用已被提出，由于其在体外激活中性粒细胞的能力。最近，PR 3也在人肾小管上皮细胞（TEC）中检测到。在本研究中，鼠单克隆抗PR 3抗体（抗PR 3）和纯化的c-ANCA靶向PR 3从WG血清对分离的人肾小管细胞信号传导和炎症介质释放的影响进行了表征。用TNF-α引发TEC导致PR 3的表面表达，如在免疫荧光研究中和通过流式细胞术定量的。此外，PR 3在表面标记的TEC上免疫沉淀。引发TEC响应抗PR 3与剂量和时间依赖性激活磷酸肌醇水解，导致肌醇磷酸的显着积累。对照IgG完全无效，而PR 3-ANCA再现了磷酸肌醇应答。信号应答伴随着超氧阴离子的显著释放到细胞上清液中。此外，大量的PGE（2）和少量的血栓烷B-2（TxA（2）的稳定代谢产物）从抗PR 3刺激的TEC中分泌。与此同时，观察到细胞内cAMP水平的升高，这被环加氧酶抑制剂吲哚美辛阻断。我们的结论是，抗PR 3抗体直接靶向肾TEC，从而引起磷酸肌醇相关的信号转导通路的显着激活。相关的代谢事件，如活性氧和脂质介质的释放可能直接导致WG肾损害的发展和肾功能的丧失。
Among the anti-neutrophil cytoplasmic Abs (ANCA), those targeting proteinase 3 (PR3) have a high sensitivity and specificity for Wegener's granulomatosis (WG). A pathogenetic role for these autoantibodies has been proposed due to their capacity of activating neutrophils in vitro. Recently, PR3 was also detected in human renal tubular epithelial cells (TEC). In the present study, the effect of murine monoclonal anti-PR3 Abs (anti-PR3) and purified c-ANCA targeting PR3 from WG serum on isolated human renal tubular cell signaling and inflammatory mediator release was characterized. Priming of TEC with TNF-alpha resulted in surface expression of PR3, as quantified in immunofluorescence studies and by flow cytometry. Moreover, PR3 was immunoprecipitated on surface-labeled TEC. Primed TEC responded to anti-PR3 with a dose- and time-dependent activation of phosphoinositide hydrolysis, resulting in a remarkable accumulation of inositolphosphates. Control IgG was entirely ineffective, whereas PR3-ANCA reproduced the phosphoinositide response. The signaling response was accompanied by a pronounced release of super-oxidanion into the cell supernatant. Moreover, large amounts of PGE(2) and, to a lesser extent, of thromboxane B-2, the stable metabolite of TxA(2), were secreted from anti-PR3-stimulated TEC. In parallel, a rise in intracellular cAMP levels was observed, which was blocked by the cyclooxygenase inhibitor indomethacin. We conclude that anti-PR3 Abs directly target renal TECs, thereby provoking pronounced activation of the phosphoinositide-related signal transduction pathway. Associated metabolic events such as the release of reactive oxygen species and lipid mediators may directly contribute to the development of renal lesions and loss of kidney function in WG.