Mechanisms of innate resistance to virus infections

对病毒感染的先天抵抗机制

• 批准号: 9288927
• 负责人: Jacob Yount
• 金额: $ 37.7万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-02-01 至 2022-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9288927
• 关键词: Adverse effects; Antiviral Agents; Biology; Cells; Cellular Membrane; Data; Ebola virus; Fibroblasts; Goals; Hemagglutinin; Human; Hydrophobicity; Image; In Vitro; Income; Infection; Infection prevention; Influenza; Integral Membrane Protein; Interferons; Knock-out; Knockout Mice; Knowledge; Link; Lipids; Lysosomes; Measures; Mediating; Membrane; Membrane Fluidity; Membrane Fusion; Modification; Molecular; Mus; PTEN gene; Pathway interactions; Peptides; Phosphoric Monoester Hydrolases; Post-Translational Regulation; Predisposition; Process; Proteins; Regulation; Regulatory Pathway; Reporter; Reporting; Resistance; Resistance to infection; Role; Severities; Shapes; Testing; Transmembrane Domain; Tumor Suppressor Proteins; Vesicle; Vesicular stomatitis Indiana virus; Viral; Virus; Virus Diseases; Work; antiviral immunity; base; cell type; design; fight against; fluorescence imaging; in vivo; influenzavirus; macrophage; mouse model; novel; pathogen; prevent; ubiquitin-protein ligase

PROJECT SUMMARY Human cells possess many intrinsic mechanisms that provide resistance to incoming virus infections, and a better understanding of these natural processes would be valuable in our ongoing fight against existing and emergent viral diseases. The interferon-induced transmembrane proteins (IFITMs) are cellular factors that potently block the fusion of multiple viruses. They are present in cells at steady state and also accumulate to higher, more effective levels during infection. IFITM3 in particular reduces the severity of influenza virus infections in both mice and humans. However, we currently lack a mechanistic understanding of how IFITM3 prevents influenza virus fusion. Likewise, we do not fully understand the regulatory processes controlling the abundance of IFITM3 in cells. We seek to bridge these fundamental gaps in our knowledge with two specific aims that will bring us closer to our long-term goal of designing IFITM3-based antivirals. Aim 1 will determine the molecular mechanism by which IFITM3 alters cellular membranes to prevent virus fusion. We have newly identified a short amphipathic helix within IFITM3 that we show is required for antiviral activity. Given that amphipathic helices are well characterized to induce membrane curvature, we will determine the ability of this helix to associate with and alter membranes, and will define its role in inhibiting influenza and other viruses. This work will provide the first evidence for an amphipathicity-based mechanism of action for the IFITMs. Aim 2 is based on our discoveries that the steady state level of IFITM3 in cells is conversely negatively regulated by the E3 ubiquitin ligase NEDD4 and positively regulated by the tumor suppressor PTEN. We have previously shown that NEDD4 directly ubiquitinates IFITM3, targeting it for degradation in lysosomes. We will now interrogate the mechanism by which PTEN promotes IFITM3 levels and resistance to influenza virus infection. We will examine which enzymatic activity of PTEN is involved in regulating IFITM3, we will determine whether PTEN and NEDD4 are involved in the same regulatory circuit, and finally, we will examine the involvement of PTEN in IFITM3-mediated resistance to infection in vivo using newly generated mouse models. Overall, these two independent aims will reveal complementary mechanisms that control IFITM3 activity and cellular abundance.

项目摘要 人类细胞具有许多固有机制，可对传入病毒感染提供抗性， 对这些自然过程的更好理解对于我们正在与现有的持续斗争而言将是有价值的 和新兴的病毒疾病。干扰素诱导的跨膜蛋白（IFITM）是细胞因素 有力阻止多种病毒的融合。它们存在于稳态的细胞中，也积聚 感染期间更高，更有效的水平。 ifitm3尤其降低了流感病毒的严重程度 小鼠和人类的感染。但是，我们目前对IFITM3的机械理解缺乏理解 防止流感病毒融合。同样，我们也不完全了解控制 细胞中的IFITM3丰度。我们试图在我们的知识中弥合这些基本差距 目的将使我们更接近设计基于IFITM3的抗病毒药的长期目标。 AIM 1将确定 IFITM3通过改变细胞膜以防止病毒融合的分子机制。我们有新的 在IFITM3内鉴定出了我们显示的抗病毒活性所需的短两亲螺旋。鉴于 两亲性螺旋的特征是诱导膜曲率，我们将确定这一点的能力 螺旋与膜结合并改变膜，并将定义其在抑制流感和其他病毒中的作用。 这项工作将为基于两亲性的行动机理提供第一个证据。目的 2基于我们的发现，即细胞中IFITM3的稳态水平相反，由 E3泛素连接酶NEDD4，并由肿瘤抑制剂PTEN阳性调节。我们以前有 表明NEDD4直接泛素化IFITM3，靶向溶酶体中的降解。我们现在会 询问PTEN促进IFITM3水平和对流感病毒感染的抗性的机制。 我们将检查PTEN的哪些酶活性参与调节IFITM3，我们将确定是否确定是否是否 PTEN和NEDD4参与了同一监管电路，最后，我们将研究 使用新生成的小鼠模型在IFITM3介导的体内感染的抗性中PTEN。总体而言，这些 两个独立的目标将揭示控制IFITM3活性和细胞的互补机制 丰富。