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型（SARS-CoV-2）是一种新近出现的流行性疾病 冠状病毒引起的疾病-19（COVID-19）的病毒和病原体。尽管科学家们 调查，关键的差距仍然存在于我们的理解基本的细胞过程，促进复制 冠状病毒，包括SARS-CoV-2，并有助于严重疾病的发病机制。 我们的初步数据表明，IRE 1 α，一种细胞对内质网反应的成分， (ER)应激是SARS-CoV-2复制和炎性细胞因子反应所必需的。但 病毒生命周期的各个阶段和介导这些效应的下游细胞途径仍然完全 未知ER应激和IRE 1 α激活与肥胖、糖尿病、 高血压和衰老，所有这些都是COVID-19严重表现的风险因素。我们假设 共病相关的ER应激引发了旺盛的病毒复制和致病性炎症， 通过IRE 1 α产生细胞因子。这个项目利用我们独特的能力来测试这个假设使用细胞 培养感染模型，以及COVID-19患者的标本。IRE 1 α抑制剂在 评估非传染性人类疾病的治疗，我们建议该项目将提供 这些药物治疗SARS-CoV-2感染的新应用的临床前证据， 其他人类冠状病毒。 本提案中概述的实验将确定IRE 1 α支持的分子机制 SARS-CoV-2感染。IRE 1 α是一种启动XBP 1 mRNA非常规剪接的核酸酶， 编码多效性转录因子。IRE 1 α还靶向其他特异性RNA，导致其降解。 我们将确定对IRE 1 α的需求是依赖于XBP 1还是独立于XBP 1，并分析 促进SARS-CoV-2复制和炎症细胞因子反应的下游细胞过程 (Aim 1）。我们将系统地确定SARS-CoV-2生命周期中需要IRE 1 α的阶段（目标2）。我们 预测IRE 1 α最有可能支持ER衍生病毒复制平台的生物发生，并将重点关注 对这个假设的实验。我们预测IRE 1 α是双重抗病毒和抗肿瘤的靶点。 炎症治疗，并将在SARS-CoV-2感染的小鼠模型中测试这一点（目的3）。最后我们将 确定IRE 1 α激活是否发生在人类感染过程中，ER应激是否是人类感染的预后标志物。 严重的COVID-19总之，这个项目的结果将揭示在细胞分裂过程中发生的基本细胞过程。 冠状病毒感染和宿主因素对COVID-19的发病机制至关重要。 .

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. .