Viral inhibition of cell death in host immune responses

病毒抑制宿主免疫反应中的细胞死亡

• 批准号: 10397097
• 负责人: Edward A Miao
• 金额: $ 58.81万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-22 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10397097
• 关键词: Apoptosis; Apoptosis Inhibitor; Binding; Biological Process; CASP8 gene; CUL1 gene; Caspase Inhibitor; Cell Death; Cell Death Inhibition; Cells; Co-Immunoprecipitations; Complex; Cowpox virus; Cullin Proteins; Defense Mechanisms; Detection; Disease; Enzymes; Exhibits; F Box Domain; Family; Goals; Herpesviridae; Human; Immune; Immune Evasion; Immune response; Immune system; Immunoprecipitation; Infection; Infiltration; Inflammation; Inflammatory; Inflammatory Response; Innate Immune Response; Knowledge; Light; Lytic; Mammalian Cell; Maps; Mediating; Medical; Modeling; Molecular; Mus; NF-kappa B; Orthopoxvirus; Outcome; Pathology; Pathway interactions; Pattern; Phosphotransferases; Poxviridae; Protein Kinase; Proteomics; RIPK1 gene; RIPK3 gene; Recombinants; Resistance; Role; Site; Small Interfering RNA; Testing; Tissues; Transfection; Ubiquitination; Vaccines; Vaccinia virus; Viral; Viral Interference; Viral Load result; Viral Physiology; Virus; Virus Diseases; Virus Inhibitors; Virus Replication; Western Blotting; Work; base; cytokine; design; domain mapping; immunopathology; in vivo; inhibitor; insight; multicatalytic endopeptidase complex; mutant; novel; pathogenic virus; response

Abstract/Summary of Work Cell death is a powerful immune defense mechanism to limit viral replication within the infected host. In response, viruses often encode inhibitors that counteract host cell death. For example, many herpesviruses and poxviruses encode inhibitors of caspases, the key enzymes that execute apoptosis. By subverting host cell death and the associated inflammatory response, viral cell death inhibitors can also dramatically alter the outcome of viral diseases. Necroptosis is a lytic form of cell death that is optimally induced in the presence of caspase 8 inhibition. As such, necroptosis has critical roles in controlling viruses that encode caspase inhibitors. Moreover, the release of “damage-associated molecular patterns (DAMPs)” from necroptotic cells can further stimulate anti- viral inflammation. These anti-viral effects suggest that necroptosis may also be a target of viral inhibition. To test this hypothesis, we conducted a siRNA screen and found a viral inhibitor from cowpox virus that we have termed “viral inducer of RIPK3 degradation (vIRD)”. In preliminary studies, we found that vIRD functions by targeting the essential necroptosis kinase RIPK3 for proteasomal degradation. Based on these observations, we propose three aims to further elucidate the function and mechanism of vIRD. In the first aim, we will evaluate the mechanism by which vIRD from cowpox virus and other related orthopoxviruses promotes RIPK3 degradation. Studies will include mapping the domain and residues within vIRD and RIPK3 that are responsible for their physical interaction and ubiquitination. In the second aim, we will interrogate the role of the host SKP1-Cullin-F box (SCF) complex in vIRD-mediated RIPK3 degradation. We will also evaluate the effect of vIRD on the global ubiquitination landscape of the infected cell. In Aim 3, we will evaluate the biological function of vIRD using mouse infection as model. We will infect mice with cowpox virus or vaccinia virus that differ in their expression of vIRD. The effect of vIRD on cell death, inflammation, viral replication and tissue pathology will be examined. Collectively, these studies will reveal medically relevant information on how viruses manipulate the immune system and alter the outcome of viral disease. We expect the knowledge gained from the proposed study will provide important insight in the design of better and more efficacious vaccines.

摘要/工作总结 细胞死亡是一种强大的免疫防御机制，可以限制病毒在受感染宿主体内的复制。在 病毒通常编码抑制剂，抵消宿主细胞死亡。例如，许多疱疹病毒 痘病毒编码半胱天冬酶的抑制剂，半胱天冬酶是执行细胞凋亡的关键酶。通过颠覆主机 细胞死亡和相关的炎症反应，病毒细胞死亡抑制剂也可以显着改变 病毒性疾病的后果。 坏死性凋亡是细胞死亡的裂解形式，其在存在胱天蛋白酶8抑制的情况下被最佳地诱导。 因此，坏死性凋亡在控制编码半胱天冬酶抑制剂的病毒中具有关键作用。而且 从坏死性凋亡细胞中释放“损伤相关分子模式（DAMP）”可以进一步刺激抗- 病毒性炎症这些抗病毒作用表明坏死性凋亡也可能是病毒抑制的靶点。到 为了验证这一假设，我们进行了siRNA筛选，发现了一种来自牛痘病毒的病毒抑制剂， 称为“RIPK 3降解的病毒诱导物（vIRD）"。在初步研究中，我们发现vIRD的功能是 靶向必需的坏死性凋亡激酶RIPK 3用于蛋白酶体降解。 基于这些观察，我们提出了三个目标，以进一步阐明功能和机制 的vid。在第一个目标中，我们将评估来自牛痘病毒和其他相关病毒的vIRD的机制， 正痘病毒促进RIPK 3降解。研究将包括绘制结构域和残基内 vIRD和RIPK 3负责它们的物理相互作用和泛素化。在第二个目标中，我们 将询问宿主SKP 1-Cullin-F盒（SCF）复合物在vIRD介导的RIPK 3降解中的作用。 我们还将评估vIRD对受感染细胞的全局泛素化景观的影响。在目标3中，我们 将使用小鼠感染作为模型来评价vIRD的生物学功能。我们将用牛痘感染老鼠 病毒或牛痘病毒，它们的vIRD表达不同。vIRD对细胞死亡，炎症， 将检查病毒复制和组织病理学。总的来说，这些研究将揭示医学相关的 关于病毒如何操纵免疫系统和改变病毒性疾病结果的信息。我们预计 从拟议的研究中获得的知识将为设计更好、更广泛的 有效的疫苗