Determinants of HIV-1 innate immune sensing and its role in shaping the lymphoid environment.

HIV-1 先天免疫感应的决定因素及其在塑造淋巴环境中的作用。

• 批准号: 10712594
• 负责人: SUMIT K CHANDA
• 金额: $ 92.25万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-12 至 2027-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10712594
• 关键词: Address; Adjuvant; Antiviral Response; Binding; Binding Proteins; Biochemical; CD4 Positive T Lymphocytes; Capsid; Cell Nucleus; Cells; Coculture Techniques; Coupled; DNA; DNA biosynthesis; Data; Dendritic Cells; Deposition; Dimerization; Disease; Environment; Equilibrium; Event; Flow Cytometry; Gene Expression; Genetic Engineering; HIV-1; Human; Immune; Immune system; Immunohistochemistry; In Vitro; Infection; Inflammatory; Inflammatory Response; Innate Immune Response; Interferon Type I; Knowledge; Length; Lymphoid; Lymphoid Tissue; Measures; Mechanics; Mediating; Modeling; Molecular; Mucous Membrane; Mutagenesis; Natural Immunity; Outcome; Pathogenesis; Pathology; Pathway interactions; Pattern; Periodicity; Proteins; Reagent; Reporting; Rest; Retroviridae; Rhesus; Role; Route; SIV; Shapes; Signal Transduction; Site; Structure; Surface; System; T-Lymphocyte; Testing; Vaccine Adjuvant; Vaccine Therapy; Variant; Viral; Viral Genes; Viral Pathogenesis; Virus; cytokine; data integration; design; dimer; experimental study; gastrointestinal; immune activation; in vivo; innate immune sensing; insight; molecular rearrangement; mucosal site; nonhuman primate; pathogen; pharmacologic; polyglutamine; prevent; recruit; response; sensor; superresolution microscopy; targeted treatment; transcriptomics; transmission process; vaccine development; vaccine strategy; viral DNA; viral transmission; Address; Adjuvant; Antiviral Response; Binding; Binding Proteins; Biochemical; CD4 Positive T Lymphocytes; Capsid; Cell Nucleus; Cells; Coculture Techniques; Coupled; DNA; DNA biosynthesis; Data; Dendritic Cells; Deposition; Dimerization; Disease; Environment; Equilibrium; Event; Flow Cytometry; Gene Expression; Genetic Engineering; HIV-1; Human; Immune; Immune system; Immunohistochemistry; In Vitro; Infection; Inflammatory; Inflammatory Response; Innate Immune Response; Interferon Type I; Knowledge; Length; Lymphoid; Lymphoid Tissue; Measures; Mechanics; Mediating; Modeling; Molecular; Mucous Membrane; Mutagenesis; Natural Immunity; Outcome; Pathogenesis; Pathology; Pathway interactions; Pattern; Periodicity; Proteins; Reagent; Reporting; Rest; Retroviridae; Rhesus; Role; Route; SIV; Shapes; Signal Transduction; Site; Structure; Surface; System; T-Lymphocyte; Testing; Vaccine Adjuvant; Vaccine Therapy; Variant; Viral; Viral Genes; Viral Pathogenesis; Virus; cytokine; data integration; design; dimer; experimental study; gastrointestinal; immune activation; in vivo; innate immune sensing; insight; molecular rearrangement; mucosal site; nonhuman primate; pathogen; pharmacologic; polyglutamine; prevent; recruit; response; sensor; superresolution microscopy; targeted treatment; transcriptomics; transmission process; vaccine development; vaccine strategy; viral DNA; viral transmission

PROJECT SUMMARY HIV-1 has a low transmission rate and most new infections via the mucosal route are initiated by a single variant out of a viral quasispecies. Recent studies in non-human primates found that mucosal transmission foci contain infected dendritic cells, and it remains to be determined why their innate responses sometimes fail to prevent viral spread. Selective advantages that allow a virus to cross a recipient's mucosal barrier include the ability to evade restriction factors and suppress innate antiviral responses. Various HIV-1 proteins participate in these evasion tactics, including the viral capsid. After entry, the capsid binds cellular factors necessary for its transit to the nucleus and synthesis of viral DNA, while repelling restriction factors and specialized innate sensors. Over the years, we have studied several innate sensors and, most recently, our studies have focused on HIV-1- dependent activation of cyclic GAMP synthase (cGAS), a cytosolic DNA sensor. We discovered that polyglutamine binding protein 1 (PQBP1) is an adaptor required for cGAS sensing of HIV-1 DNA. PQBP1 binds to the HIV-1 capsid, thereby authenticating it as a danger signal, then recruits cGAS to the capsid as it begins to disassemble and reveal the nascent viral DNA. We assume that PQBP1 transfers cGAS to the emerging DNA by a "bait and switch" mechanism, resulting in cGAS activation and downstream gene expression. We identified both naturally occurring and genetically engineered capsid variants that activate cGAS to different levels, suggesting that capsid structure is a key determinant of this innate pathway. A critical gap in our knowledge that will be addressed by this project is how PQBP1-capsid interactions and molecular rearrangements control the strength of the cGAS signal (Aims 1 and 2). The cGAS pathway is predominanUy responsible for innate immune responses triggered by HIV-1 infection of dendritic cells, resulting in expression of antiviral factors and type I interferons as well as proinflammatory cytokines. Paradoxically, while induction of antiviral genes inhibits replication, proinflammatory cytokines can activate resting CD4+ T cells and may promote infection. We hypothesize that the strength of the cGAS signal activated by HIV-1 can tip the balance from antiviral to proinflammatory responses, thereby contributing to successful transmission. The same mechanism may also be activated in other lymphoid tissues, downstream of the initial transmission event, and may determine the course of reservoir seeding. Another critical gap in our knowledge that will be addressed by this project is how the level of cGAS activation drives the balance between antiviral and proinflammatory responses and the role of the HIV- 1 capsid in determining its magnitude, both in vitro and in vivo (Aim 3). Our findings will provide insight into the molecular events that determine the outcome of viral exposure, and these same mechanisms could also contribute to HIV-1 pathogenesis. Additionally, our findings will provide important guidance for the design of appropriate adjuvant and vaccine strategies for HIV-1 and other pathologies that involve the cGAS pathway.

项目摘要 HIV-1的传输速率较低，大多数通过粘膜途径的新感染是由病毒式准特性的单个变体启动的。在非人类灵长类动物的最新研究发现，粘膜传播灶含有感染的树突状细胞，并且尚待确定为什么他们的先天反应有时无法预防病毒扩散。允许病毒越过受体的粘膜屏障的选择性优势包括逃避限制因素并抑制先天抗病毒反应的能力。各种HIV-1蛋白参与了这些逃避策略，包括病毒式衣壳。进入后，衣壳结合了其转移所必需的细胞因子与病毒DNA的合成，而排斥限制因子和专门的先天传感器。多年来，我们研究了几个先天传感器，最近，我们的研究集中在胞质DNA传感器的Cyclic GAMP合酶（CGAS）的HIV-1依赖性激活上。我们发现聚谷氨酰胺结合蛋白1（PQBP1）是HIV-1 DNA的CGAS感应所需的适配器。 PQBP1结合HIV-1 CAPSID，从而将其作为危险信号进行身份验证，然后将CGA募集到CAPSID时，因为它开始拆卸并揭示新生的病毒DNA。我们假设PQBP1通过“诱饵和开关”机制将CGA转移到新兴的DNA中，从而导致CGAS激活和下游基因表达。我们确定了将CGA激活到不同水平的自然发生的和遗传性的capsid变体，这表明衣壳结构是该先天途径的关键决定因素。该项目将解决的一个关键差距是PQBP1-CAPSID相互作用和分子重排如何控制CGAS信号的强度（目标1和2）。 CGAS途径主要是由树突状细胞感染引发的先天免疫反应，导致抗病毒因子和I型干扰素以及促炎细胞因子的表达。矛盾的是，抗病毒基因的诱导抑制了复制，但促炎细胞因子可以激活静息CD4+ T细胞，并可能促进感染。我们假设HIV-1激活的CGA信号的强度可以使从抗病毒到促炎反应的平衡使得成功传播。同样的机制也可以在其他淋巴组织（初始传播事件的下游）中激活，并可能决定储层播种的过程。该项目将解决的另一个关键差距是CGA激活的水平如何推动抗病毒和促炎反应之间的平衡以及HIV-1 Capsid在确定其体外和体内确定其大小中的作用（AIM 3）。我们的发现将提供对决定病毒暴露结果的分子事件的见解，这些相同的机制也可能有助于HIV-1发病机理。此外，我们的发现将为HIV-1和其他涉及CGAS途径的HIV-1和其他病理的适当辅助和疫苗策略的设计提供重要的指导。