Design and characterization of α1-antitrypsin variants for treatment of contact system-driven thromboinflammation
Design and characterization of α1-antitrypsin variants for treatment of contact system-driven thromboinflammation
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DOI：
10.1182/blood.2019000481
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发表时间：
2019-11-07
期刊：
影响因子：
20.3
通讯作者：
Maas, Coen
中科院分区：
文献类型：
--
作者：
de Maat, Steven;Sanrattana, Wariya;Maas, Coen
接触系统产生炎症肽缓激肽并导致实验性血栓形成。 C1 酯酶抑制剂 (C1INH) 缺乏或 XII 因子 (FXII) 功能获得性突变会导致遗传性血管性水肿，这是一种危及生命的组织肿胀疾病。 C1INH是一种相对较弱的接触系统酶抑制剂。尽管 α 1-抗胰蛋白酶 (α 1AT) 本身不会抑制接触系统酶，但人类突变 ((MR)-R-358；α 1AT-匹兹堡) 将其转变为强大的广谱酶抑制剂。它不仅阻断接触系统，而且还阻断凝血酶和活化蛋白 C (APC)，使其成为治疗性接触系统阻断的候选者。我们采用了 alpha 1AT-Pittsburgh (AIPR/S) 的反应中心环路来克服这些障碍。两种 alpha 1AT 变体（SMTR/S 和 SLLR/S）强烈抑制血浆激肽释放酶、活化的 FXII 和纤溶酶。 α1AT-SMTR/S 不再抑制凝血酶，但仍会抑制 APC。相比之下，α1AT-SLLR/S 残留抑制凝血酶，但不再抑制 APC。 P1'位置 (S -> V) 的额外修饰消除了两种变体对凝血酶和 APC 的残余抑制，同时保留了它们作为接触系统抑制剂的特性。 α1AT-SMTR/V 和 -SLLR/V 在减少血浆中缓激肽产生方面均优于 C1INH。由于它们能够选择性地阻断接触系统驱动的凝血，这两种变体都可以在动脉血栓形成的体内模型中阻断血管闭塞。此外，两种变体都能阻止小鼠中角叉菜胶引起的急性组织水肿。最后，α1AT-SLLR/V，我们最强大的候选者，可抑制结肠炎小鼠模型中肠道上皮渗漏。我们的研究结果证实，α1AT 的重新设计强烈改变了其抑制行为，可用于治疗接触系统介导的血栓形成和炎症。
The contact system produces the inflammatory peptide bradykinin and contributes to experimental thrombosis. C1 esterase-inhibitor (C1INH) deficiency or gain-of-function mutations in factor XII (FXII) cause hereditary angioedema, a life-threatening tissue swelling disease. C1INH is a relatively weak contact system enzyme inhibitor. Although alpha 1-antitrypsin (alpha 1AT) does not naturally inhibit contact system enzymes, a human mutation ((MR)-R-358; alpha 1AT-Pittsburgh) changes it into a powerful broad-spectrum enzyme inhibitor. It blocks the contact system, but also thrombin and activated protein C (APC), making it an unattractive candidate for therapeutic contact system blockade. We adapted the reactive center loop of alpha 1AT-Pittsburgh (AIPR/S) to overcome these obstacles. Two alpha 1AT variants (SMTR/S and SLLR/S) strongly inhibit plasma kallikrein, activated FXII, and plasmin. alpha 1AT-SMTR/S no longer inhibits thrombin, but residually inhibits APC. In contrast, alpha 1AT-SLLR/S residually inhibits thrombin, but no longer APC. Additional modification at the P1' position (S -> V) eliminates residual inhibition of thrombin and APC for both variants, while retaining their properties as contact system inhibitors. Both alpha 1AT-SMTR/V and -SLLR/V are superior to C1INH in reducing bradykinin production in plasma. Owing to their capacity to selectively block contact system-driven coagulation, both variants block vascular occlusion in an in vivo model for arterial thrombosis. Furthermore, both variants block acute carrageenan-induced tissue edema in mice. Finally, alpha 1AT-SLLR/V, our most powerful candidate, suppresses epithelial leakage of the gut in a mouse model of colitis. Our findings confirm that redesign of alpha 1AT strongly alters its inhibitory behavior and can be used for the treatment of contact system-mediated thrombosis and inflammation.