Role of IRE1 Alpha in Coronavirus Infections

项目摘要 严重急性呼吸综合征冠状病毒-2(SARS-CoV-2)是一种新近出现的、目前正在流行的病毒 冠状病毒诱发疾病的病毒和病原体-19(新冠肺炎)。尽管涌现出大量的科学研究 调查发现，我们对促进复制的基本细胞过程的理解仍然存在严重差距 冠状病毒，包括SARS-CoV-2，并有助于严重疾病的发病。 我们的初步数据表明，细胞对内质网的反应中的一种成分IRE1α (Er)应激，是SARS-CoV-2复制和炎症细胞因子反应所必需的。然而， 病毒生命周期的阶段(S)和介导这些影响的下游细胞通路仍然完全保留 未知。内质网应激和IRE1α激活与肥胖、糖尿病、 高血压和衰老，所有这些都是新冠肺炎严重表现的危险因素。我们假设 与共病相关的内质网应激启动了活跃的病毒复制和致病性炎症 通过Ire 1α产生细胞因子。该项目利用我们独特的能力，使用CELL来验证这一假设 培养感染模型，以及新冠肺炎患者的标本。IRE1α抑制剂正在研制中 对非传染性人类疾病的治疗进行评估，我们建议该项目将提供 这些药物用于治疗SARS-CoV-2感染的新应用的临床前证据 其他人类冠状病毒。 这项提案中概述的实验将确定IRE1α支持的分子机制(S) SARS-CoV-2感染。IRE1α是一种核酸酶，它启动XBP1mRNA的非常规剪接，它 编码一种多效性转录因子。IRE1α还针对其他导致其降解的特定RNA。 我们将确定对IRE1XBP1的需求是依赖于α还是独立的，并剖析 促进SARS-CoV-2复制和炎性细胞因子反应的下游细胞过程 (目标1)。我们将系统地确定SARS-CoV-2生命周期中需要IRE1α的阶段(S)(目标2)。我们 预测IRE1α最有可能支持内质网衍生病毒复制平台的生物发生，并将专注于 对这一假设的实验。我们预测，IRE1α是抗病毒和抗病毒双重靶点。 炎症治疗，并将在SARS-CoV-2感染的小鼠模型上进行测试(目标3)。最后，我们会 确定IRE1α是否在人类感染期间激活，内质网应激是预测 严重的新冠肺炎。总而言之，该项目的结果将揭示发生在 冠状病毒感染和宿主因素在新冠肺炎发病机制中的关键作用。 。

Project Summary Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a recently emergent, currently pandemic virus and etiological agent of Coronavirus Induced Disease-19 (COVID-19). Despite a flood of scientific investigation, critical gaps remain in our understanding of the basic cellular processes that facilitate replication of coronaviruses, including SARS-CoV-2, and contribute to the pathogenesis of severe disease. Our preliminary data demonstrate that IRE1α, a component of the cellular response to endoplasmic reticulum (ER) stress, is required for SARS-CoV-2 replication and inflammatory cytokine responses. However, the stage(s) of the viral life cycle and downstream cellular pathways that mediate these effects remain completely unknown. ER stress and IRE1α activation are well-associated with conditions such as obesity, diabetes, hypertension, and aging, all of which are risk factors for severe manifestations of COVID-19. We hypothesize that comorbidity-associated ER stress primes both exuberant viral replication and pathogenic inflammatory cytokine production via IRE1α. This project leverages our unique ability to test this hypothesis using cell culture infection models, as well as specimens from patients with COVID-19. IRE1α inhibitors are under evaluation for treatment of non-infectious human diseases, and we propose that this project will provide preclinical evidence for the novel application of these drugs to treat infections with SARS-CoV-2 and potentially other human coronaviruses. The experiments outlined in this proposal will determine the molecular mechanism(s) by which IRE1α supports SARS-CoV-2 infection. IRE1α is a nuclease which initiates nonconventional splicing of XBP1 mRNA, which encodes a pleiotropic transcription factor. IRE1α also targets other specific RNAs leading to their degradation. We will determine whether the requirement for IRE1α is XBP1-dependent or -independent and dissect the downstream cellular processes that facilitate SARS-CoV-2 replication and inflammatory cytokine responses (Aim 1). We will systematically identify stage(s) of the SARS-CoV-2 life cycle that require IRE1α (Aim 2). We predict that IRE1α most likely supports biogenesis of ER-derived viral replication platforms, and will focus experiments on this hypothesis. We predict that IRE1α represents a target for dual anti-viral and anti- inflammatory therapy and will test this in mouse models of SARS-CoV-2 infection (Aim 3). Finally, we will determine whether IRE1α activation occurs during human infection and ER stress is a prognostic marker for severe COVID-19. Together, the results of this project will reveal basic cellular processes occurring during coronavirus infection and host factors critical for the pathogenesis of COVID-19. .