The role of N-chlorination, a novel oxidative post-translational modification, in host-pathogen interactions and chronic inflammation

N-氯化（一种新型氧化翻译后修饰）在宿主-病原体相互作用和慢性炎症中的作用

• 批准号: 521368577
• 负责人: Professor Dr. Lars Leichert
• 金额: --
• 依托单位: Abteilung Biochemie der Mikroorganismen
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/521368577?language=en
• 关键词: role; chlorination; novel; oxidative; post

Hypochlorous acid (HOCl), produced by immune cells during the so-called oxidative burst, is a highly toxic oxidant. To survive their encounter with HOCl-producing immune cells, bacteria have evolved numerous defense mechanisms against this antibacterial compound. In 2014, we found that RidA is a bacterial redox-regulated chaperone that helps Escherichia coli to survive HOCl exposure. This chaperone is activated by N-chlorination, a novel HOCl-induced post-translational modification. We also found that this N-chlorination is fully reversible through NADPH-dependent reduction by the thioredoxin system. Since then, we and others have discovered more proteins that undergo N-chlorination upon exposure to HOCl, some of bacterial (like CnoX) and others of human origin (like serum albumin and other plasma proteins). These N-chlorinated proteins have been shown to have both immunomodulatory as well as protective properties. However, until now, most of these findings are based on in vitro observations. A regulatory role in host-pathogen interactions and potentially chronic inflammation of this modification is, thus, only implied. Here we propose to develop the chemical tools that will allow us, for the first time, to study the (patho-)physiological role of N-chlorination in vivo, too. At first, we plan to biochemically characterize protein N-chloramine reduction by thioredoxin in order to identify the molecular mechanism that links N-chlorination to the thiol-disulfide homeostasis. This will reveal the underpinnings of the integration of N-chlorination, as a regulatory modification, in host-pathogen interactions and chronic inflammation. In parallel, we intend to synthesize a set of probes for the detection and quantification of protein N-chloramines. We plan to characterize these probes and develop a chemoproteomic methodology to quantify the extent of protein N-chlorination in vivo, based on our prior experience in quantitative redox proteomics. With these tools we will then be able to determine the role of the thioredoxin and glutathione system in cellular N-chloramine homeostasis in E. coli exposed to HOCl and immune cells. Additionally, we will, for the first time, attempt to detect protein N-chlorination in samples from patients suffering from juvenile idiopathic arthritis, determining the clinical relevance of this novel post translational modification under severe chronic inflammation.

次氯酸（HOCl），由免疫细胞在所谓的氧化爆发期间产生，是一种高毒性氧化剂。为了在与产生HOCl的免疫细胞的相遇中生存下来，细菌已经进化出许多针对这种抗菌化合物的防御机制。在2014年，我们发现RidA是一种细菌氧化还原调节的伴侣蛋白，有助于大肠杆菌在HOCl暴露中存活。这种分子伴侣被N-氯化激活，这是一种新的HOCl诱导的翻译后修饰。我们还发现，这种N-氯化是完全可逆的，通过NADPH依赖性还原的硫氧还蛋白系统。从那时起，我们和其他人已经发现了更多的蛋白质，在暴露于HOCl时经历N-氯化，一些细菌（如CnoX）和其他人源性（如血清白蛋白和其他血浆蛋白）。这些N-氯化蛋白质已被证明具有免疫调节和保护特性。然而，到目前为止，大多数这些发现都是基于体外观察。因此，仅暗示了这种修饰在宿主-病原体相互作用和潜在慢性炎症中的调节作用。在这里，我们建议开发的化学工具，这将使我们能够，第一次，研究（病理）生理作用的N-氯化在体内，太。首先，我们计划生物化学表征蛋白质N-氯胺还原硫氧还蛋白，以确定连接N-氯化巯基-二硫化物稳态的分子机制。这将揭示N-氯化作为调节修饰在宿主-病原体相互作用和慢性炎症中的整合的基础。同时，我们打算合成一套探针的检测和定量蛋白N-氯胺。我们计划表征这些探针，并开发一种化学蛋白质组学方法来量化体内蛋白质N-氯化的程度，基于我们以前在定量氧化还原蛋白质组学方面的经验。有了这些工具，我们将能够确定硫氧还蛋白和谷胱甘肽系统在细胞N-氯胺稳态中的作用。暴露于HOCl和免疫细胞的大肠杆菌。此外，我们将首次尝试检测幼年特发性关节炎患者样本中的蛋白质N-氯化，确定这种新型翻译后修饰在严重慢性炎症下的临床相关性。