Role of HIV-1 capsid in innate sensing of viral nucleic acids

HIV-1衣壳在病毒核酸先天感知中的作用

• 批准号: 10481252
• 负责人: Jenna Eschbach
• 金额: $ 3.27万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10481252
• 关键词: AIDS/HIV problem; Acquired Immunodeficiency Syndrome; Anti-Retroviral Agents; Antiretroviral drug resistance; Antiviral Response; Biology; Capsid; Capsid Proteins; Cell Fractionation; Cells; Clinical; Clustered Regularly Interspaced Short Palindromic Repeats; Complex; Cytoplasm; Cytosol; Degradation Pathway; Development; Dissociation; Drug Targeting; Drug resistance; Enzymes; Epidemic; Genes; Genome; HIV-1; HIV-1 integrase; Host Defense Mechanism; Immune; Immunoprecipitation; Infection; Inflammatory; Innate Immune Response; Integrase; Interferons; Knock-out; Mediating; Mutation; Nuclear; Nucleic Acids; Outcome; Pathway interactions; Patients; Pharmaceutical Preparations; Phenotype; Play; Process; Proteins; RNA; RNA Binding; RNA Degradation; RNA I; Regimen; Reporting; Reverse Transcriptase Polymerase Chain Reaction; Reverse Transcription; Ribonucleoproteins; Role; Small Interfering RNA; Stimulator of Interferon Genes; Toll-like receptors; Vaccines; Viral; Viral Genome; Viral Proteins; Virion; Virus; Virus Replication; antiretroviral therapy; chemokine; crosslink; cytokine; drug development; experimental study; gag Gene Products; genomic RNA; innate immune sensing; insight; knock-down; monocyte; multicatalytic endopeptidase complex; mutant; novel; novel therapeutics; particle; premature; prevent; receptor; response; sensor; success; targeted treatment; viral RNA; viral genomics

Abstract Despite the development of dozens of drugs since the start of the HIV/AIDS epidemic, the emergence of drug resistance and lack of a vaccine or cure necessitate the development of new antiretroviral compounds. The HIV-1 capsid (CA) protein plays essential roles throughout the viral replication cycle. After an immature HIV-1 virion buds from a host cell, the structural Gag polyprotein undergoes proteolytic cleavage and rearrangement. The retroviral core is formed when rings of CA, held together by intra- and inter-subunit interactions, arrange into a conical lattice around the viral genomic RNA (gRNA) and enzymes. Since many CA-CA interactions are required to form a stable lattice, CA is genetically fragile and a favorable drug target. In fact, compounds that successfully target CA assembly and stability have recently been developed as part of long-acting drug regimens and show great promise clinically. Following their release into the cytoplasm of target cells, HIV-1 cores undergo an uncoating process in which CA subunits are shed from the core. It is now evident that proper uncoating is crucial for subsequent steps in virus replication, including reverse transcription, nuclear entry, and integration. We have recently demonstrated that destabilization of the CA lattice through mutations and CA-targeting compounds increases the propensity to form aberrant virus particles. In these particles, the gRNA and enzymes are localized between the CA lattice and viral envelope. Interestingly, this phenotype has striking similarities with the eccentric virions that are generated by inhibition of integrase (IN)-gRNA interactions. We have shown that the lack of protection by the CA lattice in both circumstances results in premature loss of gRNA and IN in a proteasome-independent manner. However, the mechanism by which IN and gRNA are degraded upon loss of CA protection remains unclear. Furthermore, recent studies have implicated that CA may shield viral nucleic acids from the host sensor proteins that initiate antiviral responses. I hypothesize that tampering with the stability of the HIV-1 CA lattice will result in premature exposure and sensing of viral nucleic acids in infected cells. Here, I propose to determine how prematurely exposed viral ribonucleoprotein complexes (vRNPs) are degraded in target cells (Aim 1). I plan to determine if altered CA stability elicits a more robust innate immune response against HIV-1 and the mechanism by which viral nucleic acids are sensed (Aim 2). Together, the results of these experiments will contribute to a better understanding of the proposed role of CA in virus replication and evasion of innate immune sensing.

摘要 尽管自艾滋病毒/艾滋病流行开始以来已经开发了数十种药物，但出现了 抗药性和缺乏疫苗或治疗方法要求开发新的抗逆转录病毒化合物。这个 HIV-1衣壳蛋白(CA)在病毒复制周期中起着至关重要的作用。在一次未成熟的HIV-1之后 病毒粒子从宿主细胞中萌发，结构上的Gag多聚蛋白经历蛋白水解性切割和重排。 逆转录病毒核心是当CA环通过亚单位内和亚基间相互作用结合在一起时形成的 病毒基因组RNA(GRNA)和酶周围的圆锥形格子。由于许多CA-CA交互是 CA需要形成稳定的晶格，在基因上是脆弱的，是一个有利的药物靶点。事实上，这种化合物 作为长效药物方案的一部分，最近成功地针对CA组装和稳定性进行了开发 并在临床上显示出很大的潜力。 在释放到靶细胞的细胞质中后，HIV-1核心经历了一个去涂层的过程 哪些CA亚基是从核心脱落的。现在很明显，正确的去涂层对于后续步骤至关重要 在病毒复制中，包括反转录、核进入和整合。我们最近做了 证明了通过突变和CA靶向化合物增加了CA晶格的不稳定性 形成异常病毒颗粒的倾向。在这些颗粒中，gRNA和酶位于 CA晶格和病毒包膜。有趣的是，这种表型与偏心的病毒粒子有惊人的相似之处。 这是通过抑制整合酶(IN)-gRNA相互作用而产生的。我们已经表明，缺乏保护 在这两种情况下，CA晶格都会导致gRNA和IN的过早丢失，导致蛋白酶体非依赖性 举止。然而，在失去CA保护后IN和gRNA被降解的机制仍然存在 不清楚。此外，最近的研究表明，CA可能会保护病毒核酸不受宿主传感器的影响 启动抗病毒反应的蛋白质。我假设篡改HIV-1 CA晶格的稳定性将 导致感染细胞过早暴露和检测到病毒核酸。在这里，我建议确定 过早暴露的病毒核糖核蛋白复合体(VRNPs)如何在靶细胞中降解(目标1)。我计划 为了确定CA稳定性的改变是否会引起对HIV-1的更强大的先天免疫反应，以及 感知病毒核酸的机制(目标2)。总而言之，这些实验的结果将 有助于更好地理解CA在病毒复制和逃避先天免疫中的作用 感官。