Evaluating the role of protein self-assembly in the innate immune system

随着人类年龄的增长，促炎细胞因子的水平增加，导致慢性炎症状态，即炎症。炎症是与年龄有关的疾病的标志，并增加了老年人的死亡率。炎症背后的分子机制尚未被阐明。因此，迫切需要阐明引起持续促炎信号的分子机制，因为这样做将加快预防和治疗年龄相关和自身炎症性疾病的努力。该建议的总体目标是确定是否有特定的分子机制有助于衰老单核细胞的促炎表型。迄今为止收集的数据表明，作为病原体识别受体下游关键节点的多个死亡域蛋白通过核限制组装机制被激活。这种组装形式的自我维持性质原则上应该允许它们无限期地持续存在并持续诱导单核细胞进行促炎信号传导。提出的目标将解决两个重要问题：1)蛋白质自组装是否足以在单核细胞中建立和维持促炎状态？2)在造血水平上，蛋白质自组装是否参与先天免疫细胞的生产和功能下降？在本研究的f99期，研究人员旨在确定驱动单核细胞持续促炎状态的分子底物。在体内测量蛋白质自组装功能的新工具的实施，将解决某些死亡结构域蛋白的组装状态是否在单核细胞中功能性地建立了促炎状态。在本研究的k00期，研究人员将确定信号体形成导致造血干细胞（HSC）衰变和自我更新受损的潜在机制。具体来说，拟议的实验将确定死亡结构域蛋白自组装是否在功能上重新编程HSC，以扭曲预加载促炎特征的髓细胞的产生。为了实现这些目标，研究人员将利用细胞学、生化和基因编辑技术开发和实施新的方法。这些目标的完成将确定炎症的分子底物，并揭示有序蛋白质自组装在信号传导和细胞分化中的未被探索的作用。提出的工作是创新的，将新兴的生物物理概念引入衰老和免疫衰老领域。

As humans age, levels of proinflammatory cytokines increase, leading to a chronic inflammatory state, known as inflammaging. Inflammation is a hallmark of age-related diseases and increases mortality among the elderly. The molecular mechanisms that underlie inflammaging have not yet been elucidated. Therefore, there is an urgent need to elucidate the molecular mechanisms causing persistent proinflammatory signals, as doing so will accelerate efforts to prevent and treat age-related and autoinflammatory diseases. The overall goal of this proposal is to determine if a specific molecular mechanism contributes to the proinflammatory phenotype of aged monocytes. The data gathered so far reveals that multiple Death Domain proteins that function as key nodes downstream of pathogen recognition receptors are activated through a nucleation-limited assembly mechanism. The self-sustaining nature of this form of assembly should in principle allow them to persist indefinitely and continuously induce monocytes for proinflammatory signaling. The proposed aims will address two important questions: 1) Do protein self-assemblies suffice to establish and maintain a proinflammatory state in monocytes? 2) Are protein self-assemblies involved in the declining production and function of innate immune cells at the hematopoiesis level? In the F99-phase of this proposed research, the researcher aims to identify the molecular substrate that drives a persistent proinflammatory state in monocytes. The implementation of novel tools to measure functionality of protein self-assemblies in vivo, will address whether the assembled states of certain Death Domain proteins are functionally establishing a proinflammatory state in monocytes. In the K00-phase of this proposed research, the researcher will identify a potential mechanism of hematopoietic stem cell (HSC) decay and impaired self-renewal caused by signalosome formation. Specifically, the proposed experiments will determine whether Death Domain protein self-assemblies functionally reprogram HSC to skew the production of myeloid cells preloaded with a proinflammatory signature. To achieve these goals, the researcher will develop and implement novel approaches using cytological, biochemical and gene editing techniques. Completion of these aims will identify molecular substrates of inflammaging and reveal an unexplored role of ordered protein self-assemblies in signaling and cell differentiation. The proposed work is innovative and brings emerging biophysical concepts to the aging and immune senescence fields.