New insights into the interplay between HIV and the autophagy machinery

HIV 与自噬机制之间相互作用的新见解

• 批准号: 10440528
• 负责人: Ruth Serra Moreno
• 金额: $ 38.68万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2026-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10440528
• 关键词: AIDS/HIV problem; APOCEC3G gene; Address; Affect; Antigen Presentation; Antiviral Response; Autophagocytosis; Autophagolysosome; Autophagosome; BCL2 gene; Binding; Cell Cycle Arrest; Cells; Data; Defect; Defense Mechanisms; Directed Molecular Evolution; Endoplasmic Reticulum; Event; Genetic Transcription; Goals; HIV; HIV Infections; Immune Evasion; Immune response; Impairment; Knowledge; Lysosomes; Mediating; Membrane; Messenger RNA; Modeling; Modification; Monoubiquitination; Parkin; Pathogenesis; Pathway interactions; Pattern recognition receptor; Play; Post-Translational Protein Processing; Predisposition; Primate Lentiviruses; Production; Property; Proteins; Proviruses; Publishing; RNA Splicing; Reporting; Research; Resistance; Role; Structure; Testing; Therapeutic; Ubiquitination; Variant; Vesicle; Viral; Viral Drug Resistance; Virion; Virulence Factors; Virus; Virus Replication; Work; antagonist; base; design; gag Gene Products; immune activation; improved; inhibitor; innovation; insight; nef Genes; novel; novel therapeutic intervention; pandemic disease; particle; pathogen; pathogenic virus; prevent; receptor; recruit; transmission process; ubiquitin-protein ligase; viral fitness; viral transmission

PROJECT SUMMARY Autophagy is an important cellular antiviral defense mechanism that potentially affects HIV infection and transmission. The antiviral properties of autophagy are two-fold: (i) autophagy targets virions for lysosomal degradation and (ii) this pathway aids in antigen presentation of virus pathogens. Despite its antiviral potential, efforts to capitalize on autophagy against HIV have been limited due to a gap in our understanding of the role of autophagy in HIV infection. Our long-term goal is to manipulate the antiviral properties of autophagy to facilitate HIV clearance and improve treatments. Our overall objective is to identify the molecular interactions between HIV and the autophagy machinery. Our central hypothesis is that autophagy restricts HIV, but the virus overcomes this block using Nef, a notorious virulence factor that mediates immune evasion. This hypothesis has been formulated based on our published and novel work demonstrating that autophagy depletes the HIV proteins Gag, Vif and Vpr, but only when nef is defective 17. Gag is the driver of virion assembly; Vif counteracts the damaging effects of the restriction factor APOBEC3G; and Vpr enhances infectivity by facilitating viral transcription and arresting cell cycle at G2. Thus, a decrease in Gag, Vif and Vpr will impact virion production and infectivity. However, we found that Nef blocks autophagy, restoring in turn HIV proteins and particle release. Our studies showed that Nef sequesters the autophagosome initiator BECN1 at the endoplasmic reticulum (ER) by facilitating its association with the autophagy inhibitor BCL2. Mechanistically, we uncovered that Nef induces BCL2 mono-ubiquitination via the E3 ligase Parkin. This post-translational modification increases BCL2's inhibitory effect over BECN1. Hence, this activity of Nef impairs autophagosome formation. The significance for this research is that: (i) it will address an important knowledge gap concerning the interplay between HIV and autophagy, and will reveal how this pathway influences HIV infection and transmission; and (ii) it will provide the basis for the design of approaches aimed at enhancing autophagy to treat HIV infection and/or improve cure strategies. We will attain the overall objective by pursuing the following three specific aims: (1) Identify HIV molecules vulnerable to autophagy; (2) Dissect the mechanism by which Nef blocks autophagy; and (3) Elucidate the impact of autophagy antagonism on HIV infectivity. The proposed research is innovative because it represents a substantive departure from the status quo by revealing that HIV critically needs Nef to counteract autophagy restriction.

项目摘要 自噬是一种重要的细胞抗病毒防御机制，可能影响HIV感染， 传输自噬的抗病毒特性有两个方面：（i）自噬针对溶酶体的病毒粒子 降解和（ii）该途径有助于病毒病原体的抗原呈递。尽管它有抗病毒的潜力， 利用自噬对抗艾滋病毒的努力受到限制，因为我们对自噬作用的理解存在差距。 HIV感染中的自噬我们的长期目标是操纵自噬的抗病毒特性， 艾滋病毒清除和改善治疗。我们的总体目标是确定分子之间的相互作用 HIV和自噬机制我们的中心假设是自噬限制了艾滋病毒，但病毒 Nef是一种臭名昭著的毒力因子，介导免疫逃避，这一假设 基于我们发表的新工作，自噬可以耗尽HIV蛋白， Gag、Vif和Vpr，但仅当nef有缺陷时17. Gag是病毒体组装的驱动器; Vif抵消了病毒体组装。 限制性因子APOBEC 3G的破坏作用; Vpr通过促进病毒感染增强感染性 转录并将细胞周期阻滞在G2期。因此，Gag、Vif和Vpr的降低将影响病毒体的产生 和传染性。然而，我们发现Nef阻断了自噬，进而恢复了HIV蛋白和颗粒的释放。 我们的研究表明Nef将自噬体起始因子BECN 1隔离在内质网（ER）上。 通过促进其与自噬抑制剂BCL 2的结合。从机制上讲，我们发现Nef诱导 通过E3连接酶Parkin的BCL 2单泛素化。这种翻译后修饰增加了BCL 2的 对BECN 1的抑制作用。因此，Nef的这种活性损害自噬体的形成。的重要意义 这项研究是：（i）它将解决有关艾滋病毒与艾滋病之间相互作用的重要知识差距， 自噬，并将揭示这一途径如何影响艾滋病毒感染和传播;（ii）它将提供 设计旨在增强自噬以治疗HIV感染和/或提高治愈率的方法的基础 战略布局我们将通过以下三个具体目标来实现总体目标：（1）识别艾滋病毒 （2）分析Nef阻断自噬的机制;（3）阐明Nef阻断自噬的机制。 自噬拮抗作用对HIV感染性的影响。这项研究是创新的，因为它 通过揭示艾滋病毒迫切需要Nef来对抗， 自噬限制