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.

项目概要 人类细胞拥有许多内在机制，可以抵抗传入的病毒感染， 更好地理解这些自然过程对于我们持续对抗现有的 和新出现的病毒性疾病。干扰素诱导的跨膜蛋白 (IFITM) 是一种细胞因子， 有效阻断多种病毒的融合。它们以稳定状态存在于细胞中并积累到 感染期间更高、更有效的水平。 IFITM3 尤其可以降低流感病毒的严重程度 小鼠和人类的感染。然而，我们目前缺乏对 IFITM3 如何机制的理解 防止流感病毒融合。同样，我们也不完全了解控制 细胞中 IFITM3 的丰度。我们寻求通过两个具体的方法来弥合我们知识中的这些基本差距 目标将使我们更接近设计基于 IFITM3 的抗病毒药物的长期目标。目标1将决定 IFITM3 改变细胞膜以防止病毒融合的分子机制。我们有新的 在 IFITM3 中发现了一个短的两亲性螺旋，我们证明它是抗病毒活性所必需的。鉴于 两亲性螺旋具有诱导膜弯曲的良好特征，我们将确定这种能力 螺旋与膜结合并改变膜，并将确定其在抑制流感和其他病毒中的作用。 这项工作将为 IFITM 的基于两亲性的作用机制提供第一个证据。目的 图2基于我们的发现，即细胞中IFITM3的稳态水平相反受到以下因素的负调节： E3 泛素连接酶 NEDD4 并受到肿瘤抑制因子 PTEN 的正向调节。我们之前有过 研究表明，NEDD4 直接泛素化 IFITM3，使其在溶酶体中降解。我们现在将 探究 PTEN 促进 IFITM3 水平和对流感病毒感染的抵抗力的机制。 我们将检查 PTEN 的哪些酶活性参与调节 IFITM3，我们将确定是否 PTEN 和 NEDD4 参与相同的调节回路，最后，我们将检查 PTEN 在 IFITM3 介导的体内抗感染中使用新生成的小鼠模型。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。