Signaling activation and constraints in maintaining immune homeostasis

先天免疫系统检测病原体衍生的分子，通过特殊的免疫来预防感染。 感受器。免疫受体包括细胞表面驻留模式识别受体(PRRs)，如 哺乳动物中的Toll样受体(TLRs)和植物中的受体激酶(RKs)，以及细胞内的Nod样蛋白 植物和哺乳动物的受体(NLR)。植物PRRs检测保守的病原菌相关分子 模式(PAMP)，而NLR识别病原体特定的效应器，最终形成统一的免疫 系统。PRR和NLR介导的免疫背后的信号网络是如何相互连接的仍然存在 很大程度上是未知的。此外，免疫受体的缺陷或过度激活可能导致细胞死亡或 自身免疫力。因此，了解启用或限制PRR和NLR激活的机制 维持免疫动态平衡尤为重要。PI的实验室已经开发出一系列 敏感和高通量的基因筛查，以剖析复杂的激活和信号机制 植物免疫，并揭示了类Malectin RKS(MLRs)在血浆中作为分子模块的重要性 连接PRR和NLR免疫受体的膜。PI的长期目标是阐明信令网络 以拟南芥为模型系统调节先天免疫反应，并扩展关于如何 宿主在不引起自身免疫性疾病的情况下抵御感染。拟议的研究植根于Pi之前的 这些发现和初步研究将支持一系列涉及几个关键知识的项目 两个相互关联的研究领域的差距。首先，研究将阐明PRR和NLR是如何介导的 信号通路汇聚成相互关联和平衡的免疫反应。具体地说，项目 将从机制上解决PRR激活的MAPK级联如何调节NLR介导的免疫 通过MLRs感知不同的多肽配体的动态平衡。其次，这项研究将破译 免疫基因编排通过分层转录，转录后， 以及单细胞水平的翻译后调控。这些项目将专注于如何相互交织在一起 翻译后修饰，包括ADP-核糖化、泛素化和磷酸化，调节 免疫特异性基因的转录、稳定性和翻译。拟议的跨学科研究将 为不同的本科生、研究生和博士后研究员提供充足的培训机会。

The innate immune system detects pathogen-derived molecules to prevent infections via specialized immune receptors. The immune receptors include cell surface-resident pattern recognition receptors (PRRs), such as Toll-like receptors (TLRs) in mammals and receptor kinases (RKs) in plants, and intracellular NOD-like receptors (NLRs) in plants and mammals. Plant PRRs detect conserved pathogen-associated molecular patterns (PAMPs), whereas NLRs recognize pathogen-specific effectors, culminating in a unified immune system. How the signaling networks underlying PRR- and NLR-mediated immunity are interconnected remains largely unknown. In addition, defects or over-activation of immune receptors could lead to cell death or autoimmunity. Thus, understanding the mechanisms that enable or constrain PRR and NLR activation for maintaining immune homeostasis is particularly important. The PI’s laboratory has developed a series of sensitive and high-throughput genetic screens to dissect the complex activation and signaling mechanisms in plant immunity, and revealed the importance of malectin-like RKs (MLRs) as a molecular module at the plasma membrane linking PRR and NLR immune receptors. PI’s long-term goal is to elucidate the signaling networks regulating innate immune responses using Arabidopsis as a model system and expand the knowledge of how hosts fend off infections without causing autoimmune disorders. The proposed research rooted in PI’s previous discoveries and preliminary studies will support a series of projects that address several critical knowledge gaps in two interrelated research areas. First, the research will elucidate how the PRR- and NLR-mediated signaling pathways converge into an interconnected and balanced immune response. Specifically, the projects will mechanistically address how a PRR-activated MAP kinase cascade regulates NLR-mediated immune homeostasis through MLRs perceiving different peptide ligands. Second, the research will decipher the immune gene orchestration through the combinatorial action of the layered transcriptional, posttranscriptional, and posttranslational regulations at the single-cell level. The projects will focus on how intertwined posttranslational modifications, including ADP-ribosylation, ubiquitination, and phosphorylation, regulate immune-specific gene transcription, stability, and translation. The proposed interdisciplinary research will provide ample training opportunities for diverse undergraduate and graduate students and postdoctoral fellows.