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.

项目概要核糖核酸酶 L (RNase L) 是哺乳动物先天抗病毒反应的关键组成部分。几十年来，RNase 据推测，L 通过裂解核糖体来阻止翻译，从而减少病毒蛋白质的合成。然而，我们和其他人最近证明，RNase L 切割的核糖体具有翻译能力，并且致病病毒可以尽管激活了 RNase L，但仍合成蛋白质。这些观察揭示了知识上的重大差距关于 RNase L 的功能以及病毒如何逃避它。我们已经证明 RNase L 可以快速降解近激活后的所有细胞 mRNA。这种活动调节三个细胞过程，扩大了我们的理解 RNase L 的研究，并阐明了致病病毒如何逃避并可能劫持 RNase L 功能。第一的， RNase L 通过降解组成型表达的细胞 mRNA 将翻译重新编程为抗病毒状态，同时保留编码抗病毒蛋白（例如 I 型干扰素）的宿主 mRNA，从而允许抗病毒蛋白合成。重要的是，由几种病原病毒（例如登革热病毒）编码的 mRNA 类似地逃避 RNase L 介导的 mRNA 衰变，从而允许病毒蛋白质合成。这一观察结果阐明了致病病毒是如何合成的尽管激活 RNase L，但蛋白质仍然存在。该应用旨在表征 RNase L 介导的 mRNA 衰减途径并确定宿主和病毒 mRNA 如何逃避它。其次，RNase L 激活触发核抑制 mRNA 输出。这是拮抗甲型流感病毒蛋白质合成的关键抗病毒机制，但它也下调宿主抗病毒蛋白（例如 I 型干扰素）的表达。重要的是，致病病毒（例如，登革热病毒）激活这种 RNase L 依赖性途径，导致宿主抗病毒 mRNA 被隔离在核。这一观察结果表明，病毒可能劫持 RNase L 的这一功能来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 输出、其拮抗病毒的广度、它如何影响致病性病毒感染期间宿主抗病毒基因的表达。三、RNase L调控组装细胞质抗病毒核糖核蛋白复合物。具体来说，RNase L 抑制应激颗粒的组装，促进另一种应激颗粒状核糖核蛋白复合物的组装，称为 RNase L 依赖性体。 RNase L 依赖性体是针对 SARS-CoV-2 或登革热病毒而组装的主要抗病毒颗粒感染，但其功能完全未知。该应用旨在确定抗病毒应激的功能颗粒和 RNase L 依赖性小体，并确定 RNase L 对其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增进我们对 OAS/RNase L 途径、先天免疫抗病毒基因诱导和病毒学。此外，还将促进普遍通过广泛表征与非传染性相关的基本细胞、分子和 RNA 生物学来研究医学疾病，包括自身免疫性疾病、神经退行性疾病和癌症。最后，拟议的研究将支持开发基于 RNase L 生物学的有前途的抗病毒、免疫调节和抗癌疗法。

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。