Generation of biologically active C-reactive protein peptides by a neutral protease on the membrane of phorbol myristate acetate-stimulated neutrophils.
Generation of biologically active C-reactive protein peptides by a neutral protease on the membrane of phorbol myristate acetate-stimulated neutrophils.
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通过佛波醇肉豆蔻酸酯醋酸盐刺激的中性粒细胞膜上的中性蛋白酶产生具有生物活性的 C 反应蛋白肽。
作者：
E. Shephard;S. M. Beer;R. Anderson;A. Strachan;A. Nel;F. C. D. Beer
研究了人C-反应蛋白（CRP）与非刺激和PMA刺激的人中性粒细胞以及伴随的CRP降解（通过TCA可溶性肽和SDS-PAGE分析监测）的相关性。125 I标记的CRP与中性粒细胞的最大关联和125 I标记的CRP在与这些细胞的关联过程中的降解是通过用10 ng/ml的PMA刺激中性粒细胞实现的;在该浓度下，嗜天青颗粒的释放并不显著。对于PMA刺激的中性粒细胞，125 I标记的CRP的关联是1.8倍高，PMA刺激的嗜中性粒细胞介导的配体降解是非刺激细胞的3倍。在不存在和存在PMA的情况下，在SDS-PAGE分析中证明了嗜中性粒细胞相关的125 I标记的CRP约50%降解。CRP降解的程度与125 I标记的CRP与中性粒细胞的相关性呈正相关。除了产生中性粒细胞相关的CRP中间体外，在CRP与中性粒细胞缔合期间还产生小的可溶性CRP肽。这些肽在10微克/毫升时抑制来自调理酵母聚糖活化的嗜中性粒细胞的超氧化物产生约40%。125 I标记的CRP降解介导的非刺激的中性粒细胞，和嗜中性粒细胞条件培养基（从非刺激和PMA刺激的细胞）是可降解的α 1-抗胰蛋白酶和约7倍，在1小时发生的125 I标记的CRP协会与PMA刺激的中性粒细胞。PMA刺激的中性粒细胞介导的125 I标记的CRP的降解不能完全被α 1-抗胰蛋白酶抑制。数据点的参与膜相关的丝氨酸蛋白酶，这是最大限度地激活PMA，在125碘标记的CRP的降解过程中与中性粒细胞。我们的研究结果表明，在炎症部位可以产生CRP衍生肽，抑制活化的中性粒细胞的作用。
The association of human C-reactive protein (CRP) with nonstimulated and PMA-stimulated human neutrophils and the concomitant degradation of CRP (monitored by TCA-soluble peptides and SDS-PAGE analysis) has been studied. Maximum association of 125I-labeled CRP with neutrophils and 125I-labeled CRP degradation during association with these cells was achieved by stimulating the neutrophils with PMA at 10 ng/ml; a concentration in which azurophil granule release was not significant. For PMA-stimulated neutrophils, the association of 125I-labeled CRP was 1.8 times higher and PMA-stimulated neutrophil-mediated degradation of the ligand was three times faster than that for nonstimulated cells. The neutrophil-associated 125I-labeled CRP in the absence and presence of PMA proved on SDS-PAGE analysis to be approximately 50% degraded. There was a positive correlation between the extent of CRP degradation and the association of 125I-labeled CRP with neutrophils. In addition to generation of neutrophil associated CRP intermediates, small soluble CRP peptides were generated during association of CRP with neutrophils. These peptides inhibited superoxide production from opsonized zymosan-activated neutrophils by approximately 40% at 10 micrograms/ml. 125I-labeled CRP degradation mediated by nonstimulated neutrophils, and neutrophil-conditioned medium (from both non-stimulated and PMA-stimulated cells) was inhibitable by alpha 1-antitrypsin and approximately seven times less at 1 h than that occurring during 125I-labeled CRP-association with PMA-stimulated neutrophils. The degradation of 125I-labeled CRP mediated by PMA-stimulated neutrophils was not fully inhibitable by alpha 1-antitrypsin. The data point to the involvement of a membrane-associated serine protease, which is maximally activated by PMA, in the degradation of 125I-labeled CRP during association with neutrophils. Our results indicate that at an inflammatory site CRP-derived peptides can be produced that inhibit the action of activated neutrophils.