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

基本信息

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
项目类别：
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

项目摘要

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.

项目概要自噬是一种重要的细胞抗病毒防御机制，可能影响 HIV 感染和传播。自噬的抗病毒特性有两个方面：（i）自噬针对溶酶体的病毒体降解和（ii）该途径有助于病毒病原体的抗原呈递。尽管它具有抗病毒潜力，由于我们对自噬作用的理解存在差距，利用自噬对抗艾滋病毒的努力受到了限制。 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，以促进清除艾滋病毒并改善治疗。我们的总体目标是确定之间的分子相互作用 HIV 和自噬机制。我们的中心假设是自噬限制了 HIV，但病毒使用 Nef（一种臭名昭著的介导免疫逃避的毒力因子）克服了这一障碍。这个假设有根据我们已发表的新颖作品制定，证明自噬会消耗 HIV 蛋白 Gag、Vif 和 Vpr，但仅限于 nef 有缺陷时 17. Gag 是病毒粒子组装的驱动程序； Vif 抵消限制因子 APOBEC3G 的破坏作用； Vpr 通过促进病毒传播来增强传染性转录和G2细胞周期停滞。因此，Gag、Vif 和 Vpr 的减少将影响病毒粒子的产生和传染性。然而，我们发现 Nef 会阻止自噬，进而恢复 HIV 蛋白和颗粒释放。我们的研究表明，Nef 在内质网 (ER) 处隔离自噬体启动子 BECN1 通过促进其与自噬抑制剂 BCL2 的结合。从机制上讲，我们发现 Nef 会诱导 BCL2 通过 E3 连接酶 Parkin 进行单泛素化。这种翻译后修饰增加了 BCL2 对BECN1有抑制作用。因此，Nef 的这种活性会损害自噬体的形成。意义对于这项研究的特点是：(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策略。我们将通过以下三个具体目标来实现总体目标： (1) 识别艾滋病毒易受自噬影响的分子；（2）剖析Nef阻断自噬的机制； (3) 阐明自噬拮抗作用对 HIV 感染性的影响。拟议的研究具有创新性，因为它通过揭示 HIV 迫切需要 Nef 来抵消，代表着对现状的实质性背离自噬限制。