Molecular Control of IFITM3 in Restricting Influenza Virus Infection

IFITM3 在限制流感病毒感染中的分子控制

• 批准号: 9012283
• 负责人: Jacob Yount
• 金额: $ 36.62万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-03-01 至 2017-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9012283
• 关键词: Accounting; Antiviral Agents; Biology; Cause of Death; Cellular Membrane; Data; Defect; Development; Drug Targeting; Ensure; Enzymes; Genetic Polymorphism; Health; Human; In Vitro; Infection; Influenza; Integral Membrane Protein; Interferon Activation; Interferons; Knowledge; Mediating; Membrane; Membrane Fluidity; Modification; Molecular; Mus; Natural Immunity; Peptides; Post-Translational Protein Processing; Predisposition; Proteins; Reporting; Research; Resistance; Series; Specificity; Therapeutic; Transmembrane Domain; Ubiquitination; Virus; Virus Diseases; Work; base; combat; cost; fighting; improved; influenzavirus; insight; novel; novel therapeutics; palmitoylation; prevent; research study; trafficking; ubiquitin-protein ligase

 DESCRIPTION (provided by applicant): Influenza virus infection and its complications remains a leading cause of death in the US, and burdens the nation economically with costs of up to $87 billion annually. We, and others, have shown that the interferon- induced transmembrane protein 3 (IFITM3) inhibits influenza virus infections in vitro, and IFITM3 has also been shown to be essential for innate resistance to influenza virus infection in both mice and humans. Despite the importance of IFITM3 in broadly inhibiting influenza and other viruses, this knowledge has not yet inspired new therapeutics because it remains unclear precisely how IFITM3 hinders viral infection and how IFITM3 trafficking and function are regulated biochemically. Our overall hypothesis is that IFITM3 stability and localization are controlled by a series of post-translational modifications that ensure proper delivery and anchoring of IFITM3 to endolysosomes, where its intramembrane domains decrease membrane fluidity to prevent influenza virus fusion/infection. Aim 1 is based on our novel discovery that the E3 ubiquitin ligase NEDD4 is a negative regulator of IFITM3 cellular levels and activity. NEDD4 may represent a novel drug target for improv- ing IFITM3-mediated innate immunity against influenza virus, and our work examining IFITM3 ubiquitination by NEDD4, and the crosstalk between this and other modifications will provide molecular details regarding IFITM3 regulatory mechanisms that must be understood in order to ultimately devise such therapeutics based on IFITM3 biology. Aim 2 is built upon our discovery that a specific DHHC domain-containing palmitoyltransferase is able to palmitoylate IFITM3, which we previously demonstrated is an essential modification necessary for IFITM3 antiviral activity. We will analyze potential IFITM3 palmitoylation defects caused by polymorphisms reported for this enzyme, thus laying the groundwork for its study as an influenza virus susceptibility factor. Our preliminary data also suggest that IFITM3 palmitoylation must occur at a specific cellular compartment for positive effects on its activity to be observed. Thus we will investigate putative DHHC localization mechanisms that account for this effect. This series of experiments will identify critical DHHC trafficking and specificity determinants, and reveal which cellular compartments support the proper palmitoylation/activation of IFITM3. In Aim 3 we will examine the function of IFITM3 intramembrane regions in altering cellular membranes to inhibit virus infections. We have provided evidence that IFITM3's predicted transmembrane domains act instead as intramembrane domains. Intramembrane domains often alter membrane structure, and our preliminary data indicates that IFITM3 indeed decreases membrane fluidity. Thus, we will examine the necessity and sufficiency of IFITM3 intramembrane domains in decreasing membrane fluidity and inhibiting virus infection. In the course of all of these studies we will appy the knowledge gained toward the development of an optimally active but minimally sized antiviral poly- peptide construct. Overall, these research aims should reveal molecular strategies for controlling and exploiting IFITM3 in fighting influenza virus and viral diseases.

 描述（由申请人提供）：流感病毒感染及其并发症仍然是美国的一个主要原因，每年给国家带来高达 870 亿美元的经济负担。蛋白 3 (IFITM3) 在体外抑制流感病毒感染，尽管 IFITM3 很重要，但 IFITM3 也被证明对于小鼠和人类对流感病毒感染的先天抵抗力至关重要。在广泛抑制流感和其他病毒方面，这一知识尚未激发新的治疗方法，因为尚不清楚 IFITM3 如何阻碍病毒感染以及 IFITM3 运输和功能如何通过生化调节。我们的总体假设是 IFITM3 稳定性和定位是由 目标 1 基于我们的新发现，即 E3 泛素连接酶 NEDD4 是一种负调节因子。 IFITM3 细胞水平和活性的 NEDD4 可能代表改善 IFITM3 介导的针对流感病毒的先天免疫的新药物靶点。 NEDD4 检测 IFITM3 泛素化的工作，以及该修饰与其他修饰之间的串扰将提供有关 IFITM3 调节机制的分子细节，为了最终设计出基于 IFITM3 生物学的此类疗法，目标 2 是建立在我们发现特定 DHHC 结构域的基础上的。含有棕榈酰转移酶的酶能够对 IFITM3 进行棕榈酰化，我们之前证明这是 IFITM3 抗病毒活性所必需的重要修饰。我们的初步数据还表明，IFITM3 棕榈酰化必须发生在特定的细胞区室，才能观察到对其活性的积极影响。因此，我们将研究解释这种效应的假定 DHHC 定位机制，这一系列实验将确定关键的 DHHC 运输和特异性决定因素，并揭示哪些细胞区室支持适当的作用。 IFITM3 的棕榈酰化/激活。在目标 3 中，我们将检查 IFITM3 膜内区域在改变细胞膜以抑制病毒感染方面的功能。我们提供的证据表明，IFITM3 的预测跨膜结构域通常会改变膜内结构域。我们的初步数据表明 IFITM3 确实降低了膜的流动性，因此，我们将检查 IFITM3 的必要性和充分性。在所有这些研究过程中，我们将应用所获得的知识来开发最佳活性但最小尺寸的抗病毒多肽构建体。总体而言，这些研究目标应该揭示控制的分子策略。利用 IFITM3 对抗流感病毒和病毒性疾病。