Deciphering the inositol phosphate code in viral pathogenesis and immunity

项目总结 肌醇磷酸盐(IP)是一种可扩散的细胞内信使(称为“IP代码”)，它执行密钥 在真核细胞中发挥作用，但这些分子对免疫和宿主防御的贡献仍然存在 开发不足。通过不偏不倚的方法，我们的实验室最近发现了知识产权的显著新角色 宿主-病毒交界处的分子：(1)在坏死性下垂期间，一个关键的促炎细胞死亡机制 用于抗病毒免疫和(2)在感染人类鼻病毒(RV)期间，最常见的 人体内的感染性病原体。我们已经发现，产生细胞内IP的IP激酶活性 签名(即IP3、IP4、IP5、IP6)通过明显不同的方式对坏死性下垂和轮状病毒感染起关键作用 机械装置。我们发现IP分子可以直接控制死亡者，混合血统 类激酶(MLKL)，以释放坏死细胞死亡。相反，我们发现轮状病毒的感染依赖于IP 在细胞死亡之前的阶段，与MLKL无关，表明IP的宿主或病毒靶标尚未确定。 然而，目前还不清楚不同的IP如何在分子水平上控制这些过程，如何 IP激酶精确协作以确定蜂窝IP代码，以及该代码如何在 感染或细胞因子刺激以调节免疫。我们的中心假设是肌醇磷酸盐和 它们的激酶在先天性免疫反应和病毒感染过程中发挥着重要的调节作用。 与宿主或病毒目标的相互作用。在这里，我们将确定参与的准确机制 由这些基本免疫过程编码的肌醇磷酸通过使用强大的遗传和 生化工具包，并将我们在分子遗传学和病毒学方面的专业知识与 肌醇磷酸盐生物学和生物化学领域的顶尖专家。具体地说，我们将(1)绘制遗传和 在细胞和生化分析中IP物种与死链执行剂MLKL的物理相互作用， (2)明确IP编码调控轮状病毒感染的分子机制(S)。一起， 这些研究将为免疫防御的调节和病毒的发病机制提供基本的见解。我们 希望这项工作为理解IP代码在免疫和感染中的作用奠定基础 并为开发新的方法来增强抗微生物和抗菌能力提供基础 炎症疗法。

PROJECT SUMMARY Inositol phosphates (IPs) are diffusible intracellular messengers (termed the “IP code”) that perform key functions in the eukaryotic cell, yet the contributions of these molecules to immunity and host defense remains underexplored. Through unbiased approaches, our laboratory has recently uncovered striking new roles for IP molecules at the host-virus interface: (1) during necroptosis, a pro-inflammatory cell death mechanism critical for antiviral immunity and (2) during infection with human rhinoviruses (RV), among the most common infectious agents in human beings. We have found that IP kinase activity that produces the cellular IP signature (i.e., IP3, IP4, IP5, IP6) is critical for both necroptosis and RV infection via apparently distinct mechanisms. We showed that IP molecules can directly control the necroptotic executioner, mixed-lineage kinase like (MLKL), to unleash necrotic cell death. In contrast, we found that RV infection depends on IPs at a stage preceding cell death and independent of MLKL, indicating as yet unidentified host or viral targets for IPs. However, it is currently unknown how the different IPs act to control these processes on a molecular level, how IP kinases precisely collaborate to determine the cellular IP code, and how this code is regulated during infection or cytokine stimulation to mediate immunity. Our central hypothesis is that inositol phosphates and their kinases play important regulatory roles in innate immune responses and during viral infection through interactions with host or viral targets. Here, we will determine the precise mechanisms for engagement of the inositol phosphate code by these fundamental immune processes by employing a robust genetic and biochemical toolkit and combining our expertise in molecular genetics and virology with a collaborative team of leading experts in inositol phosphate biology and biochemistry. Specifically, we will (1) map the genetic and physical interactions of IP species with the necroptotic executioner MLKL in cellular and biochemical assays, and (2) define the molecular mechanism(s) governing regulation of RV infection by the IP code. Together, these studies will provide fundamental insight into regulation of immune defenses and viral pathogenesis. We expect this work to form a foundation for understanding the roles of the IP code in immunity and infection biology and to provide a basis for development of novel methods to enhance anti-microbial and anti- inflammatory therapeutics.