Elucidating the role of lipids in positive-sense RNA virus infection.

阐明脂质在正义 RNA 病毒感染中的作用。

• 批准号: 416701689
• 负责人: Professorin Dr. Eva Herker
• 金额: --
• 依托单位: Institut für Virologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/416701689?language=en
• 关键词: Elucidating; role; lipids; positive; sense

Intracellular pathogens critically depend on host cell metabolic pathways for replication and/or persistent infection. We hypothesize that positive-sense RNA viruses require common lipid metabolic pathways for their replication. Hepatitis C virus (HCV) replication depends on cholesterol ester and triglyceride biosynthesis as well as de novo cholesterol and fatty acid synthesis. The HCV RNA is replicated by RNA replication complexes within ER-derived membrane structures termed the membranous web that is detergent-resistant due to the presence of lipids that are associated with lipid microdomains, namely cholesterol and sphingolipids. Importantly, inhibition of cholesterol and sphingomyelin biosynthesis suppresses viral RNA replication in cells and cholesterol-lowering agents such as statins may be beneficial for therapeutic success. In addition, fatty acid synthase (FASN) enzymatic activity is required for the creation of altered membrane structures in the replication cycle of Flaviviridae family members including HCV, dengue virus (DENV), yellow fever virus (YFV), Usutu virus (USUV), and West Nile virus (WNV). Accordingly, inhibition of FASN leads to a drastic inhibition of viral replication. However, the precise changes in the lipid metabolism of mammalian cells infected with different members of the Flaviviridae family are currently unknown. We recently investigated in-depth the HCV-induced changes in the lipid composition and performed quantitative shotgun lipidomic studies of whole cell extracts and subcellular compartments. Our results indicate that HCV infection reduces the ratio of neutral to membrane lipids. In addition, HCV-infected cells had a higher relative abundance of phosphatidylcholines and triglycerides with longer fatty acyl chains and a striking increased utilization of C18 fatty acids, most prominently oleic acid. Accordingly, depletion of fatty acid elongases and desaturases impaired HCV replication and/or assembly and release of particles. Taken together our preliminary results demonstrate the complex remodeling of the host cell lipid metabolism induced by HCV to enhance both virus replication and progeny production.Here, we propose to perform lipidomic studies of HCV-related viruses such as DENV, YFV, and Zika virus (ZIKV) to compare and contrast the metabolic rewiring by viruses of the Flaviviridae family. These studies will uncover similarities and differences in lipid remodeling that will be probed for their relevance for viral replication. Second, we will study in great mechanistic detail the function of specific fatty acid elongases and desaturases and their enzymatic products in the formation of viral RNA replication vesicles. The final aim will elucidate the role of polyunsaturated fatty acids in virion morphogenesis.

细胞内病原体的复制和/或持续感染在很大程度上依赖于宿主细胞代谢途径。我们假设，阳性RNA病毒的复制需要共同的脂类代谢途径。丙型肝炎病毒的复制依赖于胆固醇酯和甘油三酯的生物合成以及胆固醇和脂肪酸的从头合成。丙型肝炎病毒RNA由内质网衍生的膜结构中的RNA复制复合体复制，该膜结构称为膜网，由于存在与脂质微域相关的脂类，即胆固醇和鞘磷脂，膜网是耐洗涤剂的。重要的是，抑制胆固醇和鞘磷脂的生物合成可以抑制病毒RNA在细胞中的复制，而他汀类降胆固醇药物可能有助于治疗的成功。此外，在包括丙型肝炎病毒、登革热病毒(DENV)、黄热病病毒(YFV)、Usutu病毒(USUV)和西尼罗河病毒(WNV)在内的黄病毒家族成员的复制周期中，脂肪酸合成酶(FASN)的活性是产生改变膜结构所必需的。因此，抑制FASN会导致病毒复制的急剧抑制。然而，感染黄毒科不同成员的哺乳动物细胞脂代谢的确切变化目前尚不清楚。我们最近深入研究了丙型肝炎病毒诱导的脂质成分的变化，并对全细胞提取物和亚细胞隔室进行了定量的脂组学研究。我们的结果表明，丙型肝炎病毒感染降低了中性与膜脂的比例。此外，感染丙型肝炎病毒的细胞具有较高的磷脂酰胆碱和甘油三酯的相对丰度，具有较长的脂肪酰链，并显著增加了对C18脂肪酸的利用，最显著的是油酸。因此，脂肪酸伸长酶和去饱和酶的缺失会损害丙型肝炎病毒的复制和/或颗粒的组装和释放。综上所述，我们的初步结果表明，丙型肝炎病毒诱导的宿主细胞脂质代谢的复杂重塑促进了病毒的复制和后代的产生。在此，我们建议对丙型肝炎病毒相关病毒如DENV、YFV和寨卡病毒(ZIKV)进行脂组学研究，以比较和对比黄病毒科病毒的代谢重连。这些研究将揭示脂质重塑的相似性和差异性，以探讨它们与病毒复制的相关性。其次，我们将详细研究特定的脂肪酸伸长酶和去饱和酶及其酶产物在病毒RNA复制囊泡形成中的作用。最终目的将阐明多不饱和脂肪酸在病毒粒子形态发生中的作用。