Understanding the OAS/RNase L pathway during pathogenic viral infections

了解病原性病毒感染期间的 OAS/RNase L 途径

基本信息

批准号：
10714902
负责人：
James M Burke
金额：
$ 48.3万
依托单位：
UNIVERSITY OF FLORIDA
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-09-15 至 2028-07-31
项目状态：
未结题

项目摘要

PROJECT SUMMARY Ribonuclease L (RNase L) is a key component of the mammalian innate antiviral response. For decades, RNase L was presumed to reduce viral protein synthesis by cleaving ribosomes to arrest translation. However, we and others recently demonstrated that RNase L-cleaved ribosomes are translation-competent, and that pathogenic viruses can synthesize proteins despite activating RNase L. These observations have revealed a significant gap in knowledge regarding how RNase L functions and how viruses evade it. We have demonstrated that RNase L rapidly degrades nearly all cellular mRNAs upon activation. This activity regulates three cellular processes that have expanded our understanding of RNase L and that have elucidated how pathogenic viruses evade and potentially hijack RNase L functions. First, RNase L reprograms translation to an antiviral state by degrading constitutively expressed cellular mRNAs while sparing host mRNAs encoding antiviral proteins (e.g., type I interferons), which permits antiviral protein synthesis. Importantly, the mRNAs encoded by several pathogenic viruses (e.g., dengue virus) similarly evade RNase L-mediated mRNA decay, thus permitting viral protein synthesis. This observation has elucidated how pathogenic viruses synthesize proteins despite activating RNase L. This application proposes to characterize the RNase L-mediated mRNA decay pathway and determine how host and viral mRNAs evade it. Second, RNase L activation triggers the inhibition of nuclear mRNA export. This is a critical antiviral mechanism that antagonizes influenza A virus protein synthesis, but it also downregulates the expression of host antiviral proteins (e.g., type I interferons). Importantly, pathogenic viruses (e.g., dengue virus) activate this RNase L-dependent pathway, resulting in sequestration of host antiviral mRNAs in the nucleus. This observation suggests that viruses potentially hijack this function of RNase L to limit host antiviral protein production. This application aims to determine how RNase L inhibits mRNA export, the breadth of viruses it antagonizes, how it impacts host antiviral gene expression during pathogenic viral infections. Third, RNase L regulates the assembly of cytoplasmic antiviral ribonucleoprotein complexes. Specifically, RNase L inhibits the assembly of stress granules and promotes the assembly of an alternative stress granule-like ribonucleoprotein complex termed RNase L-dependent body. RNase L-dependent bodies are the predominant antiviral granule assembled in response to SARS-CoV-2 or dengue virus infection, yet their function is completely unknown. This application aims to determine the function of antiviral stress granules and RNase L-dependent bodies and to determine how their regulation by RNase L alters the antiviral response. Understanding the mechanisms and functions of these cellular processes will advance our understanding of the OAS/RNase L pathway, innate immune antiviral gene induction, and virology. Moreover, it will promote general medicine by broadly characterizing fundamental cellular, molecular, and RNA biology that is relevant to non-infectious diseases, including autoimmune diseases, neurodegeneration, and cancer. Lastly, the proposed research will support the development of promising antiviral, immunomodulatory, and anticancer therapies based on RNase L biology.

项目摘要核糖核酸酶L（RNase L）是哺乳动物先天抗病毒反应的关键组成部分。数十年来，RNase 假定L通过裂解核糖体阻止翻译来减少病毒蛋白的合成。但是，我们和其他人最近证明了RNase L-裂解的核糖体具有翻译能力，而致病性病毒可以尽管激活了RNaseL。关于RNase L的功能以及病毒如何逃避。我们已经证明rNase l迅速降解激活后所有细胞mRNA。这项活动调节了三个蜂窝过程，这些过程扩大了我们的理解 RNase L的含量并阐明了致病性病毒逃避和潜在劫持RNase L功能的方式。第一的， RNASE L通过降解组成表达的细胞mRNA而将翻译转换为抗病毒状态保留编码抗病毒蛋白的宿主mRNA（例如I型干扰素），该蛋白允许抗病毒蛋白合成。重要的是，由多种致病病毒（例如登革热病毒）编码的mRNA类似地逃避了RNase L介导的 mRNA衰变，因此允许病毒蛋白质合成。该观察结果阐明了致病性病毒的合成方式尽管激活了RNaseL。蛋白质。该应用建议表征RNase L介导的mRNA衰变途径并确定宿主和病毒mRNA如何逃避它。其次，RNase L激活触发了核的抑制 mRNA导出。这是一种关键的抗病毒机制，它拮抗流感的一种病毒蛋白质合成，但也下调宿主抗病毒蛋白的表达（例如，I型干扰素）。重要的是，致病病毒（例如登革热病毒）激活该RNase L依赖性途径，导致宿主抗病毒mRNA的隔离核。该观察结果表明，病毒潜在地劫持了RNase L的这种功能以限制宿主抗病毒蛋白生产。该应用旨在确定RNASE L如何抑制mRNA导出，它拮抗病毒的广度，它如何影响致病病毒感染期间宿主抗病毒基因表达。第三，rNase l调节组件细胞质抗病毒核糖核蛋白复合物的。具体而言，rNase l抑制压力颗粒的组装和促进称为RNase L依赖性体的替代应力颗粒样核糖核蛋白复合物的组装。 RNase L依赖性体是响应于SARS-COV-2或登革热病毒的主要抗病毒颗粒感染，但它们的功能是完全未知的。该应用旨在确定抗病毒应力的功能颗粒和RNase l依赖性身体，并确定其通过RNASE的调节如何改变抗病毒反应。了解这些细胞过程的机制和功能将提高我们对 OAS/RNase L途径，先天免疫抗病毒基因诱导和病毒学。而且，它将促进一般通过广泛表征与非感染有关的基本细胞，分子和RNA生物学的医学疾病，包括自身免疫性疾病，神经变性和癌症。最后，拟议的研究将支持基于RNase L生物学的有希望的抗病毒，免疫调节和抗癌疗法的开发。

项目成果

期刊论文数量（2）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

G3BP1-dependent condensation of translationally inactive viral RNAs antagonizes infection.

DOI：
10.1126/sciadv.adk8152
发表时间：
2024-02-02
期刊：
SCIENCE ADVANCES
影响因子：
13.6
作者：
Burke, James M.;Ratnayake, Oshani C.;Watkins, J. Monty;Perera, Rushika;Parker, Roy
通讯作者：
Parker, Roy

RNase L-induced bodies sequester subgenomic flavivirus RNAs and re-establish host RNA decay.

RNase L 诱导的体隔离亚基因组黄病毒 RNA 并重新建立宿主 RNA 衰变。