Species-Specific Endotoxin Stimulus Determines Toll-Like Receptor 4- and Caspase 11-Mediated Pathway Activation Characteristics.
Species-Specific Endotoxin Stimulus Determines Toll-Like Receptor 4- and Caspase 11-Mediated Pathway Activation Characteristics.
复制标题
DOI：
10.1128/msystems.00306-21
复制
发表时间：
2021-08-31
期刊：
影响因子：
6.4
通讯作者：
Nita-Lazar A
中科院分区：
文献类型：
--
作者：
Ernst O;Khan MM;Oyler BL;Yoon SH;Sun J;Lin FY;Manes NP;MacKerell AD Jr;Fraser IDC;Ernst RK;Goodlett DR;Nita-Lazar A
先天免疫系统是人体抵御病原体和感染性疾病的第一道防线。在宿主骨髓细胞的表面，Toll样受体4（TLR 4）感知脂多糖（LPS），其是革兰氏阴性菌的主要外膜组分。在细胞内，LPS通过非典型炎性体被caspase 11识别，以诱导裂解性细胞死亡的炎性形式-热解。虽然TLR 4介导的信号转导干扰导致细胞因子和趋化因子的分泌，有助于清除感染和促进适应性免疫，但胱天蛋白酶11介导的细胞凋亡导致损伤相关分子模式和炎症介质的释放。虽然TLR 4信号通路中的核心信号事件和许多相关蛋白是已知的，但非经典炎性体通路中的复杂信号事件和蛋白网络仍然不清楚。此外，越来越多的证据表明病原体特异性先天免疫调节。我们从两种不同的病原体的主要LPS结构的特点，模拟其结合到表面受体，系统地检查巨噬细胞炎症反应，这些LPS分子，并调查了全球蛋白分泌的时间差异TLR 4和caspase 11激活巨噬细胞使用质谱（MS）为基础的定量蛋白质组学。这种综合策略，跨越功能活性测定，自上而下的内毒素的结构阐明，和刺激的巨噬细胞的分泌组分析，使我们能够确定TLR 4和半胱天冬酶11介导的蛋白质分泌响应两个革兰氏阴性细菌内毒素的关键差异。重要性巨噬细胞和单核细胞是先天性免疫细胞，在协调细菌感染和组织损伤的初始先天性免疫应答中发挥重要作用。这种反应由细胞表面和细胞内的特异性受体促进。所识别的细菌分子之一是革兰氏阴性细菌细胞壁组分，脂多糖（LPS）。LPS的结构在不同物种之间存在差异。我们的特点是先天性免疫反应的LPS分子从两种细菌，大肠杆菌和百日咳杆菌，给予细胞外或细胞内，其结构，我们首先确定。我们观察到这些分子和途径中的任何一种刺激的先天免疫细胞分泌的蛋白质的时间动态和量的显著差异。这表明对不同革兰氏阴性菌的第一线反应具有特异性，可以探索以定制特定的治疗干预措施。
The innate immune system is the body’s first line of defense against pathogens and its protection against infectious diseases. On the surface of host myeloid cells, Toll-like receptor 4 (TLR4) senses lipopolysaccharide (LPS), the major outer membrane component of Gram-negative bacteria. Intracellularly, LPS is recognized by caspase 11 through the noncanonical inflammasome to induce pyroptosis—an inflammatory form of lytic cell death. While TLR4-mediated signaling perturbations result in secretion of cytokines and chemokines that help clear infection and facilitate adaptive immunity, caspase 11-mediated pyroptosis leads to the release of damage-associated molecular patterns and inflammatory mediators. Although the core signaling events and many associated proteins in the TLR4 signaling pathway are known, the complex signaling events and protein networks within the noncanonical inflammasome pathway remain obscure. Moreover, there is mounting evidence for pathogen-specific innate immune tuning. We characterized the major LPS structures from two different pathogens, modeled their binding to the surface receptors, systematically examined macrophage inflammatory responses to these LPS molecules, and surveyed the temporal differences in global protein secretion resulting from TLR4 and caspase 11 activation in macrophages using mass spectrometry (MS)-based quantitative proteomics. This integrated strategy, spanning functional activity assays, top-down structural elucidation of endotoxins, and secretome analysis of stimulated macrophages, allowed us to identify crucial differences in TLR4- and caspase 11-mediated protein secretion in response to two Gram-negative bacterial endotoxins. IMPORTANCE Macrophages and monocytes are innate immune cells playing an important role in orchestrating the initial innate immune response to bacterial infection and the tissue damage. This response is facilitated by specific receptors on the cell surface and intracellularly. One of the bacterial molecules recognized is a Gram-negative bacteria cell wall component, lipopolysaccharide (LPS). The structure of LPS differs between different species. We have characterized the innate immune responses to the LPS molecules from two bacteria, Escherichia coli and Bordetella pertussis, administered either extracellularly or intracellularly, whose structures we first determined. We observed marked differences in the temporal dynamics and amounts of proteins secreted by the innate immune cells stimulated by any of these molecules and routes. This suggests that there is specificity in the first line of response to different Gram-negative bacteria that can be explored to tailor specific therapeutic interventions.