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: 10323127
• 负责人: Ruth Serra Moreno
• 金额: $ 39.19万
• 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/10323127
• 关键词: AIDS/HIV problem; APOCEC3G gene; Address; Affect; Antigen Presentation; Antiviral Agents; 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; 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; base; design; gag Gene Products; immune activation; improved; inhibitor/antagonist; innovation; insight; nef Genes; novel; novel therapeutic intervention; pandemic disease; parkin gene/protein; 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，可能会影响HIV感染和 传播。自噬的抗病毒特性是两倍：（i）自噬靶标病毒体的溶酶体 降解和（ii）该途径有助于病毒病原体的抗原表现。尽管具有抗病毒潜力，但 由于我们对自己的作用差距，努力利用对艾滋病毒的自噬的努力受到限制 自噬在HIV感染中。我们的长期目标是操纵自噬的抗病毒特性以促进 HIV清除并改善治疗方法。我们的总体目标是确定分子相互作用 艾滋病毒和自噬机械。我们的中心假设是自噬限制了艾滋病毒，但病毒 使用NEF克服了这一区块，NEF是介导免疫逃避的臭名昭著的毒力因子。这个假设有 根据我们出版的新颖工作制定了表明自噬耗尽HIV蛋白的作品 GAG，VIF和VPR，但仅当NEF有缺陷17时，GAG是病毒座组件的驱动力； Vif抵消 限制因子APOBEC3G的损害影响； VPR通过促进病毒来增强感染力 G2处的转录和阻止细胞周期。因此，堵嘴，VIF和VPR的减少将影响病毒粒子的产生 和感染力。但是，我们发现NEF会阻止自噬，恢复HIV蛋白并释放颗粒。 我们的研究表明，NEF隔离在内质网（ER）处的自噬体启动器BECN1 通过促进其与自噬抑制剂BCL2的关联。从机械上讲，我们发现NEF诱导了 Bcl2通过E3连接酶Parkin的单素化。这种翻译后的修改增加了Bcl2的 对BECN1的抑制作用。因此，这种NEF的活性会损害自噬体的形成。意义的意义 这项研究是：（i）它将解决有关艾滋病毒和艾滋病毒之间相互作用的重要知识差距 自噬，并将揭示该途径如何影响HIV感染和传播； （ii）它将提供 设计旨在增强自噬治疗艾滋病毒感染和/或改善治愈方法的方法的基础 策略。我们将通过追求以下三个特定目标来实现总体目标：（1）确定艾滋病毒 分子容易受到自噬的影响； （2）解剖NEF阻止自噬的机制； （3）阐明 自噬拮抗作用对艾滋病毒感染性的影响。拟议的研究具有创新性，因为它 通过揭示艾滋病毒需要NEF来抵消，代表与现状的实质性不同 自噬限制。