Rip Proteins in Innate Immune Signaling

撕裂先天免疫信号中的蛋白质

• 批准号: 8384857
• 负责人: MICHELLE ALICE KELLIHER
• 金额: $ 34.1万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-12-15 至 2013-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8384857
• 关键词: Address; Affect; Alleles; Anti-Bacterial Agents; Antigen-Presenting Cells; Antiviral Response; Attenuated; Bacteria; Binding; Cells; Chronic; Clinical; Communicable Diseases; Crohn' s disease; Cytokine Activation; Data; Dendritic Cells; Disease; Embryo; Enzymes; Fibroblasts; Goals; Host Defense; Human; Immune; Immune response; In Vitro; Infection; Inflammatory; Interferon Type I; Ligands; Link; Lysine; Mediating; Mediator of activation protein; Mitogen-Activated Protein Kinases; Modification; Mus; Mutation; Nucleotides; Pathway interactions; Peptidoglycan; Pharmaceutical Preparations; Polyubiquitin; Polyubiquitination; Production; Proteins; Publishing; Receptor Signaling; Recruitment Activity; Research; Role; Signal Transduction; Site; Syndrome; TLR3 gene; TLR4 gene; TNF gene; TNFRSF1A gene; Tertiary Protein Structure; Testing; Toll-like receptors; Tuberculosis; Ubiquitin; Ubiquitination; Viral; Viral Physiology; Virus; Virus Diseases; Work; activating transcription factor; adapter protein; base; cytokine; design; fighting; human disease; in vivo; induced pluripotent stem cell; interferon regulatory factor-7; macrophage; microbial; novel; pathogen; receptor; response; transcription factor; ubiquitin-protein ligase

The cytokine TNF, the pathogen recognition Toll-like receptors (TLRs) and the nucleotide binding oligomerization domain (NOD) proteins mediate host defense against infection in part by activating the transcription factor NF-¿B. Our published work reveals Rip1 as a critical mediator of the TNF- and TLR3/4, Trif-dependent NF-¿B pathways and the ubiquitin modification of Rip1 is essential for TNF- induced NF-¿B activation and cytokine production. We find Rip1-deficient cells impaired in their type I interferon response to viral infection, revealing that Rip1 contributes to Rig-I/Mda5 anti-viral signaling. Our recent studies reveal a novel regulatory role for Rip1 in the ubiquitination and activation of the interferon regulatory factor 7 (IRF-7), a transcription factor critical for type I interferon production. Therefore, we hypothesize that Rip1 and potentially polyubiquitinated Rip1 mediate anti-viral innate immune responses by regulating NF-¿B and IRF-7 activity. To support this hypothesis, we will test whether a Rip1-deficiency impairs innate anti-viral responses in vivo and will infect Rip1-deficient macrophages and dendritic cells with multiple classes of viruses to determine how Rip1 regulates the transcriptional activity of IRF-7 (Aim 1). Activation of the TNF, Trif or Rig-I/Mda5 pathways stimulates Rip1 polyubiquitination, hence we will test whether polyubiquitinated Rip1 is required for the activation of NF-¿B and/or IRF-7 in virally infected cells and will determine whether an inability to ubiquitin modify Rip1 results in impaired innate anti-viral responses (Aim 2). Similarly, our studies on the related Rip1 protein Rip2 find endogenous Rip2 polyubiquitinated in MDP-stimulated macrophages, suggesting that the Nod2 pathway is ubiquitin-regulated. We hypothesize that polyubiquitinated Rip2 is required for Nod2-mediated NF-¿B activation and for innate anti-bacterial immune responses and predict that ubiquitin deregulation contributes to NOD2-associated human inflammatory diseases. To test this hypothesis, we will identify the critical ubiquitin site on Rip2 and will test whether polyubiquitinated Rip2 is required for Nod-mediated NF-¿B activation and will determine how expression of NOD2 alleles associated with human inflammatory diseases affect the recruitment and polyubiquitination of Rip2 (Aim3). Collectively, our studies suggest that innate immune responses are ubiquitin regulated, raising the possibility that the enzymes responsible for the ubiquitin modification of Rip proteins may be targeted therapeutically to treat infectious disease or chronic inflammatory disease.

细胞因子 TNF、病原体识别 Toll 样受体 (TLR) 和核苷酸结合 寡聚化结构域 (NOD) 蛋白部分通过激活 转录因子 NF-¿B。我们发表的工作揭示了 Rip1 是 TNF-α 和 TLR3/4、Trif 依赖性 NF-¿B 通路和 Rip1 的泛素修饰对于 TNF-α 至关重要 诱导 NF-κB 激活和细胞因子产生。我们发现 Rip1 缺陷细胞的 I 型受损 干扰素对病毒感染的反应，揭示 Rip1 有助于 Rig-I/Mda5 抗病毒信号传导。 我们最近的研究揭示了 Rip1 在泛素化和激活中的新调节作用 干扰素调节因子 7 (IRF-7)，一种对 I 型干扰素产生至关重要的转录因子。 因此，我们假设 Rip1 和潜在的多泛素化 Rip1 介导先天抗病毒作用 通过调节 NF-¿B 和 IRF-7 活性来调节免疫反应。为了支持这个假设，我们将测试 Rip1 缺陷是否会损害体内先天抗病毒反应并会感染 Rip1 缺陷 巨噬细胞和树突状细胞与多种病毒，以确定 Rip1 如何调节 IRF-7 的转录活性（目标 1）。 TNF、Trif 或 Rig-I/Mda5 途径的激活刺激 Rip1 多泛素化，因此我们将测试激活是否需要多泛素化 Rip1 病毒感染细胞中的 NF-¿B 和/或 IRF-7，并将确定是否无法进行泛素修饰 Rip1 导致先天抗病毒反应受损（目标 2）。同样，我们对相关Rip1的研究 Rip2 蛋白在 MDP 刺激的巨噬细胞中发现内源性 Rip2 多泛素化，这表明 Nod2 通路受泛素调节。我们假设多泛素化的 Rip2 是 Nod2 介导的 NF-¿B 激活和先天抗菌免疫反应并预测 泛素失调会导致 NOD2 相关的人类炎症性疾病。为了测试这个 假设，我们将识别 Rip2 上的关键泛素位点，并测试 Rip2 是否多泛素化 是 Nod 介导的 NF-¿B 激活所必需的，并将决定 NOD2 等位基因的表达方式 与人类炎症性疾病相关的 Rip2 募集和多聚泛素化 （目标3）。总的来说，我们的研究表明先天免疫反应是由泛素调节的，提高了 负责 Rip 蛋白泛素修饰的酶可能是 针对性治疗传染病或慢性炎症性疾病。