Deciphering the inositol phosphate code in viral pathogenesis and immunity

项目摘要 肌醇磷酸（IP）是可扩散的细胞内信使（称为“IP代码”），其执行关键的细胞内信号传导。 这些分子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。 探索不足我们的实验室通过公正的方法，最近发现了知识产权的惊人的新作用 在宿主-病毒界面的分子：（1）在坏死性凋亡期间，促炎细胞死亡机制至关重要 抗病毒免疫和（2）在感染人类鼻病毒（RV），其中最常见的 人类的传染源我们发现产生细胞IP的IP激酶活性 签名（即，IP 3，IP 4，IP 5，IP 6）通过明显不同的途径对坏死性凋亡和RV感染都至关重要 机制等我们发现IP分子可以直接控制坏死性凋亡的执行者， 激酶样（MLKL），以释放坏死细胞死亡。相比之下，我们发现RV感染取决于IP， 细胞死亡之前的阶段，并且与MLKL无关，表明IP的宿主或病毒靶点尚未确定。 然而，目前尚不清楚不同的IP如何在分子水平上控制这些过程， IP激酶精确地协作以确定细胞IP代码，以及在细胞内如何调节该代码。 感染或细胞因子刺激以介导免疫。我们的中心假设是肌醇磷酸和 它们的激酶在先天免疫应答和病毒感染过程中起重要的调节作用， 与宿主或病毒靶点的相互作用。在这里，我们将确定参与的确切机制， 肌醇磷酸编码这些基本的免疫过程，通过采用一个强大的遗传和 生物化学工具包，并将我们在分子遗传学和病毒学方面的专业知识与 磷酸肌醇生物学和生物化学领域的顶尖专家。具体来说，我们将（1）绘制遗传图谱， IP物质与坏死性凋亡执行者MLKL在细胞和生物化学测定中的物理相互作用， 和（2）确定IP编码调控RV感染的分子机制。在一起， 这些研究将提供对免疫防御调节和病毒发病机理的基本认识。我们 我希望这项工作能为理解IP编码在免疫和感染中的作用奠定基础 生物学，并为开发新的方法以增强抗微生物和抗微生物的能力提供基础。 炎症治疗学。

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.