Characterization and Modulation of Caspase 4-Mediated Pyroptosis

项目摘要/摘要 先天免疫系统是抵御内源性和外源性威胁的第一道防线， 既是效应者又是激活者的双重角色。然而，当先天免疫系统对刺激反应过于强烈时， 这可能会导致宿主死亡，我们通常将这种现象称为“败血症”。败血症经常与 感染革兰氏阴性细菌，如大肠杆菌或铜绿假单胞菌，推测是由 它们的免疫原性物质，其中脂多糖(脂多糖)可能在这种异常的过度信号中发挥关键作用。 这项提议概述了一项研究内毒素细胞内受体的计划，这是最近发现的一种现象，似乎是 内毒素血症的原因，尽管这种受体的确切性质背后的机制仍不清楚。通过探测 无论是酶的激活还是其下游的蛋白降解事件的特征，我们计划识别该受体是否 内毒素诱导人类细胞系统休克的根本原因，因为敲除其小鼠同源基因具有保护作用 内毒素直接注射到小鼠体内时会发生休克。除了进一步刻画这种细胞内的基本性质 LPs受体，我们将发起一项筛选活动，以确定对这种酶有偏好的选择性分子，而不是 与其关系密切的家族成员。这项建议产生的数据应该确定有效的治疗方法 败血症和感染性休克逆转的靶点，一种正确诊断败血症的生物标志物，或一种新的、高度敏感的 检测血清中内毒素的方法。

Project Summary/Abstract The innate immune system is the first-line of defense against both endogenous and exogenous threats, serving dual roles as both effectors and activators. However, when the innate immune system responds too robustly to a stimulus, this can lead to the host’s demise, a phenomenon we frequently call “sepsis”. Sepsis is frequently associated with infection by a gram-negative bacterial agent such as E. coli or P. aeruginosa and has been hypothesized to be driven by their immunogenic substances, with lipo-polysaccharide (LPS) likely playing a critical role in this aberrant over-signaling. This proposal outlines a plan to study the intracellular receptor of LPS, a recently discovered phenomenon seemingly the cause of endotoxemia, although the mechanisms underlying the exact nature of this receptor are still unknown. By probing both the enzyme’s activation and characterizing its downstream proteolytic events, we plan to identify if this receptor is the root cause of LPS-induced shock in human cell systems, as knockout of its murine homolog is protective against endotoxin shock when directly injected into mice. In addition to further characterizing the basic nature of this intracellular LPS receptor, we will initiate a screening campaign to identify selective molecules with a preference for this enzyme, over its closely related family members. The data generated by this proposal should identify either a validated therapeutic target for the reversal of sepsis and septic shock, a biomarker for the proper diagnosis of sepsis, or a new, highly sensitive assay for the detection of endotoxin in serum.