Mechanistic elucidation of inflammasome assembly and regulation. Supplement: Testing drugs that curtail inflammasome activation to suppress SARS-CoV-2 pathogenesis

摘要 炎性小体是一种超分子信号复合物，可激活半胱天冬酶的一个亚类 称为炎性半胱天冬酶如半胱天冬酶-1。在微生物的刺激下， 损伤相关的信号，炎性小体组装引发宿主防御的第一道防线， 细胞因子IL-1b和IL-18的蛋白水解成熟，以及通过诱导热凋亡细胞死亡。 炎性小体的组装需要激活上游传感器、下游传感器和下游传感器。 效应物，且在大多数情况下是衔接分子，如凋亡相关斑点样蛋白 含有胱天蛋白酶募集结构域（ASC）。根据是否需要ASC， 炎性小体可分为ASC依赖型和ASC非依赖型 炎性小体尽管炎性小体在先天免疫中具有生物学重要性，但没有 结构和机械信息是可用的。 这项提议试图将SARS-CoV-2感染与炎性小体联系起来，并测试是否 炎性体抑制剂减轻SARS-CoV-2的发病机制。炎性小体激活， 特别是通过NLRP 3炎性体和孔形成蛋白GSDMD， 严重的，往往是致命的细胞因子风暴，肺部炎症和败血症， 严重急性呼吸道综合征2型临床恶化它甚至可能导致淋巴细胞减少症，这是一个重要的 严重COVID-19病例的特征。这些数据来自SARS-CoV-2和相关的 冠状病毒，SARS-CoV和MERS-CoV，使我们提出了以下假设： 由SARS-CoV-2引起的严重急性呼吸综合征（SARS）肺炎是由 大量炎性细胞浸润和促炎细胞因子/趋化因子升高 依赖于GSDMD和/或NLRP 3激活的应答。

Abstract Inflammasomes are supramolecular signaling complexes that activate a subset of caspases known as inflammatory caspases such as caspase-1. Upon stimulation by microbial and damage-associated signals, inflammasomes assemble to elicit the first line of host defense by proteolytic maturation of cytokines IL-1b and IL-18, and by induction of pyroptotic cell death. Assembly of an inflammasome requires activation of an upstream sensor, a downstream effector, and in most cases an adaptor molecule such as apoptosis-associate speck-like protein containing a caspase recruitment domain (ASC). Depending on whether ASC is required, inflammasomes can be categorized into ASC-dependent and ASC-independent inflammasomes. Despite the biological importance of inflammasomes in innate immunity, no structural and mechanistic information is available. This proposal seeks to link SARS-CoV-2 infection to inflammasomes and to test whether inflammasome inhibitors alleviate SARS-CoV-2 pathogenesis. Inflammasome activation, in particular through the NLRP3 inflammasome and the pore forming protein GSDMD, underlies the serious, and often fatal cytokine storm, lung inflammation and sepsis that are associated with SARS-CoV-2 clinical deterioration. It may even contribute to lymphopenia, an important characteristic of severe COVID-19 cases. These data from SARS-CoV-2 and from related coronaviruses, SARS-CoV and MERS-CoV, led us to propose the following hypothesis: the severe acute respiratory syndrome (SARS) pneumonia induced by SARS-CoV-2 is caused by massive inflammatory cell infiltration and elevated proinflammatory cytokine/chemokine responses that depend on GSDMD and/or NLRP3 activation.