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.

抽象的 尽管自艾滋病毒/艾滋病流行以来已经开发了数十种药物，但 耐药性和缺乏疫苗或治疗方法需要开发新的抗逆转录病毒化合物。这 HIV-1 衣壳 (CA) 蛋白在整个病毒复制周期中发挥着重要作用。未成熟的 HIV-1 感染后 当病毒体芽从宿主细胞中分离出来时，结构性 Gag 多蛋白会经历蛋白水解裂解和重排。 当通过亚基内和亚基间相互作用结合在一起的 CA 环排列成 病毒基因组 RNA (gRNA) 和酶周围的圆锥形网格。由于许多 CA-CA 相互作用是 CA 是形成稳定晶格所必需的，它在遗传上很脆弱，是有利的药物靶点。事实上，化合物 成功靶向 CA 组装和稳定性最近已被开发为长效药物方案的一部分 并在临床上显示出巨大的前景。 HIV-1 核心释放到靶细胞的细胞质中后，会经历脱壳过程 哪些 CA 亚基从核心脱落。现在很明显，正确的脱漆对于后续步骤至关重要 病毒复制，包括逆转录、进入核和整合。我们最近有 证明通过突变和 CA 靶向化合物会增加 CA 晶格的不稳定 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，这种表型与古怪的病毒体有惊人的相似之处 是通过抑制整合酶 (IN)-gRNA 相互作用而产生的。我们已经证明，缺乏保护 在这两种情况下，CA 晶格都会导致 gRNA 和 IN 在不依赖于蛋白酶体的情况下过早丢失 方式。然而，IN 和 gRNA 在失去 CA 保护后被降解的机制仍然存在 不清楚。此外，最近的研究表明 CA 可以保护病毒核酸免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 导致受感染细胞中病毒核酸的过早暴露和感知。在此，我建议确定 过早暴露的病毒核糖核蛋白复合物 (vRNP) 如何在靶细胞中降解（目标 1）。我计划 以确定改变的 CA 稳定性是否会引发针对 HIV-1 和 病毒核酸的感知机制（目标 2）。这些实验的结果将共同 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 传感。