A novel mechanism for NLRP3 inflammasome activation in human macrophages

感染和细胞应激可触发细胞质模式识别受体组装 炎症体复合体，促进炎性细胞因子IL-1β、IL-18和 诱导嗜热性细胞死亡。炎症性反应也会持续存在并传播给旁观者。 细胞。最终，这种反应有助于病原体清除和伤口愈合。然而，过度 炎性小体激活可导致与炎症性疾病相关的衰弱症状 疾病。特别是，NLRP3炎症小体与许多疾病直接相关。它有一个 不仅可以感知感染，还可以感知细胞压力和组织损伤，从而实现独特的定位。即使是在 NLRP3炎症体对于平衡动态平衡和疾病是至关重要的，并且是 因此，作为新治疗策略的主要靶点，潜在的分子机制，特别是在 人类的巨噬细胞，仍然知之甚少。有许多人类炎性小体成分 在小鼠身上不存在，它们对人类健康和疾病的功能贡献甚至更不清楚 而不是更保守的因素。阐明人类独特的反应是我们实验室的主要关注点。 先天免疫受体寡聚引发包括炎症体在内的炎性宿主反应 激活。这项提案中概述的研究旨在机械地解开一种新型的NLRP3 人巨噬细胞中的炎性小体激活概念。我们发现了一个新的NLRP3炎症体 人巨噬细胞中与NLRP3相互作用但在小鼠中不存在的成分，我们的初步研究 研究表明，NLRP3需要这种共同传感器来进行寡聚以及招募 炎性小体适配器，ASC。此外，NLRP3及其辅助传感器是有效成核所必需的 ASC聚合和caspase-1激活。共传感器现象拷贝NLRP3基因敲除在 人类巨噬细胞。值得注意的是，由NLRP3突变驱动的细胞因子释放是绝对必要的 会导致低温相关周期综合征(CAPS)。我们提出了两个具体的目标来调查 共感受器在NLRP3炎症体组装和激活中的机制和作用 巨噬细胞，以及使这种协同传感器能够促进NLRP3炎症体的分子事件 激活。我们将利用CRISPR/Cas9敲除和恢复野生型和突变型共传感器的表达 蛋白质和表达人类共传感器的人源化小鼠，用于研究其在体内的功能。 我们预计，我们的研究将发现新的分子机制，不仅改变我们目前的 了解防止NLRP3炎症体不适当激活的控制机制 维持动态平衡和人类健康，也是炎症性疾病中NLRP3驱动的病理。 我们的研究结果将推动该领域的发展，并将对理解疾病具有非常重要的意义 这项研究的目的是为了使患者受益并对人类健康产生积极影响的新疗法的开发。

Infections and cellular stress can trigger cytoplasmic pattern recognition receptors to assemble an inflammasome complex, which promotes the release of the inflammatory cytokines IL-1β, IL-18 and the induction of pyroptotic cell death. Inflammasome responses are also perpetuated and propagated to bystander cells. Ultimately, this response contributes to pathogen clearance and wound healing. However, excessive inflammasome activation can contribute to- or cause debilitating symptoms associated with inflammatory diseases. Particularly, the NLRP3 inflammasome has been directly linked to numerous diseases. It has a unique position by not only sensing infections, but also cellular stress and tissue damage. Even though the NLRP3 inflammasome is of utmost importance for balancing between homeostasis and disease, and is therefore a prime target for novel treatment strategies, the underlying molecular mechanisms, particularly in human macrophages, are still poorly understood. There are numerous human inflammasome components that are absent in mice and their functional contribution to human health and disease are even less well understood than the more conserved factors. Elucidating unique human responses is the main focus of our lab. Innate immune receptor oligomerization initiates inflammatory host responses, including inflammasome activation. The research outlined in this proposal is designed to mechanistically unravel a novel NLRP3 inflammasome activation concept in human macrophages. We discovered a novel NLRP3 inflammasome component in human macrophages, which interacts with NLRP3, but is absent from mice and our preliminary studies revealed that NLRP3 requires this co-sensor for oligomerization as well as for recruiting the inflammasome adaptor, ASC. Furthermore, NLRP3 and its co-sensor are necessary for efficiently nucleating ASC polymerization and caspase-1 activation. Knock out of the co-sensor phenocopies NLRP3 knock out in human macrophages. Significantly, it is absolutely necessary for cytokine release driven by NLRP3 mutations that cause Cryopyrin-Associated Periodic Syndrome (CAPS). We propose two specific aims that investigate the mechanism and function of the co-sensor in NLRP3 inflammasome assembly and activation in macrophages, as well as the molecular events that enable this co-sensor to promote NLRP3 inflammasome activation. We will utilize CRISPR/Cas9 knock out and restored expression of wild type and mutant co-sensor proteins and a humanized mouse expressing the human co-sensor for studying its function in vivo. We expect that our research will uncover novel molecular mechanisms that not only change our current understanding of control mechanisms that prevent inappropriate NLRP3 inflammasome activation for maintaining homeostasis and human health, but also NLRP3-driven pathologies in inflammatory diseases. The outcomes of our study will move the field forward and will be highly significant for understanding disease pathologies and for the development of novel therapies that benefit patients and positively affect human health.