Human mechanisms of virus persistence in an AAV-based mouse model of chronic HBV infection

基于 AAV 的慢性 HBV 感染小鼠模型中病毒持续存在的人类机制

• 批准号: 10159211
• 负责人: MICHAEL ROBEK
• 金额: $ 49.16万
• 依托单位: ALBANY MEDICAL COLLEGE
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-06 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10159211
• 关键词: Acute Hepatitis; Affect; Animal Model; Antibodies; Apoptosis; Apoptotic; B-Lymphocytes; Blood; CD8-Positive T-Lymphocytes; CTLA4 gene; Cell physiology; Cell surface; Cells; Cessation of life; Chronic Hepatitis B; Cirrhosis; Dependovirus; Development; Dioxygenases; Environment; Enzymes; Foundations; Frequencies; Functional disorder; Future; Goals; Health; Hepatitis B Virus; Hepatocyte; Human; Immune; Immune System Diseases; Immune Tolerance; Immune response; Immunization; Immunologics; Immunotherapeutic agent; Immunotherapy; Infection; Interleukin-10; Knowledge; Ligands; Liver; Liver diseases; Malignant Neoplasms; Measures; Mediating; Mediator of activation protein; Metabolic; Metabolic Pathway; Modeling; Mus; Natural Killer Cells; Pathway interactions; Patients; Peripheral; Phenotype; Physiological; Production; Proteins; Publishing; Receptor Signaling; Regulation; Regulatory Pathway; Regulatory T-Lymphocyte; Reproducibility; Research; Risk; Role; Signal Pathway; Signal Transduction; T cell response; T-Lymphocyte; T-bet protein; TNFSF10 gene; Testing; Tissues; Transforming Growth Factor beta; Viral; Viral Antigens; Viral Genome; Virus; Virus Diseases; Virus Replication; adaptive immune response; amino acid metabolism; antiviral immunity; arginase; base; chronic infection; cytokine; exhaustion; experimental study; improved; indoleamine; insight; intrahepatic; mouse model; novel therapeutic intervention; programmed cell death protein 1; receptor; receptor function; therapeutic immunization; therapeutic vaccine; transcription factor; vaccine efficacy; vector-based vaccine; virus host interaction

PROJECT SUMMARY Chronic hepatitis B virus (HBV) infection is associated with an ineffective T cell response that fails to control the virus. While the precise mechanism of T cell dysfunction in chronic hepatitis B is not well understood, prior studies using blood and liver tissue from acute and chronic HBV patients have identified a number of critical immunological mechanisms that may contribute to this poor immune response. These mechanisms include the killing of HBV-specific T cells by liver-resident natural killer (NK) cells, a general tolerogenic environment in the liver that is manifested by immunosuppressive immune cells, cytokines, and metabolic pathways, and the loss of T cell function through inhibitory receptor signaling pathways and exhaustion. The study of HBV-host interactions and the development of new curative immunotherapies for chronic hepatitis B have been hampered by the lack of physiological animal models for chronic infection. A new mouse model of HBV replication was recently described that is based on adeno-associated virus (AAV)-mediated transduction of the liver with the HBV genome, which leads to persistent virus replication and immune tolerance to HBV antigens. Compared to other mouse models of HBV replication, the AAV-HBV model has important advantages, including physiological intrahepatic immune priming, technical ease and reproducibility, peripheral T and B cell tolerance to HBV, and the ability to study virus elimination from the liver. Using this model, we will test the hypothesis that HBV therapeutic vaccine efficacy can be enhanced by manipulating mechanisms of immune dysfunction to promote viral clearance. Our general approach will be to combine AAV-HBV transduction with genetically modified mice and antibody-mediated depletion/blockade to evaluate the importance of immune cells, cytokines, and regulatory pathways for eliciting functional CD8+ T cell responses and controlling HBV following therapeutic immunization. To evaluate our hypothesis, we will carry out three specific aims. First, we will assess the inhibition of HBV- specific T cells by NK cells. Second, we will define the role of regulatory cells, cytokines, and metabolic pathways. Third, we will evaluate T cell inhibitory receptor function and exhaustion. The knowledge that will be gained from this research will impact the field in two important ways. First, it will provide new mechanistic insight into the relationship between T cell dysfunction and HBV persistence, and form a strong foundation for future studies using the AAV-HBV model to better understand the virus-host interactions that are observed in humans. Second, it will reveal new immunotherapeutic targets for potential approaches to cure chronic HBV infection.

项目概要 慢性乙型肝炎病毒 (HBV) 感染与无效的 T 细胞反应有关，无法控制乙型肝炎病毒 病毒。虽然慢性乙型肝炎 T 细胞功能障碍的确切机制尚不清楚，但之前 使用急性和慢性乙型肝炎患者的血液和肝组织进行的研究已经确定了一些关键的 可能导致这种不良免疫反应的免疫机制。这些机制包括 肝脏驻留的自然杀伤 (NK) 细胞杀死 HBV 特异性 T 细胞，这是肝脏中普遍的耐受环境 肝脏，表现为免疫抑制性免疫细胞、细胞因子和代谢途径，以及损失 通过抑制性受体信号通路和耗竭来影响 T 细胞功能。乙型肝炎病毒宿主的研究 慢性乙型肝炎的相互作用和新的治疗性免疫疗法的开发受到阻碍 由于缺乏慢性感染的生理动物模型。一种新的乙肝病毒复制小鼠模型 最近描述的基于腺相关病毒（AAV）介导的肝脏转导 HBV 基因组，导致病毒持续复制和对 HBV 抗原的免疫耐受。相比 与其他HBV复制小鼠模型相比，AAV-HBV模型具有重要的优势，包括生理学 肝内免疫启动、技术简便性和可重复性、外周 T 和 B 细胞对 HBV 的耐受性，以及 研究病毒从肝脏消除的能力。使用这个模型，我们将检验乙型肝炎病毒的假设 可以通过操纵免疫功能障碍的机制来增强治疗性疫苗的功效，以促进 病毒清除。我们的总体方法是将 AAV-HBV 转导与转基因小鼠相结合 和抗体介导的耗竭/阻断，以评估免疫细胞、细胞因子和调节的重要性 治疗性免疫后引发功能性 CD8+ T 细胞反应和控制 HBV 的途径。 为了评估我们的假设，我们将实现三个具体目标。首先，我们将评估对 HBV- 的抑制作用 NK 细胞的特异性 T 细胞。其次，我们将定义调节细胞、细胞因子和代谢途径的作用。 第三，我们将评估 T 细胞抑制性受体功能和耗竭。将从中获得的知识 这项研究将以两个重要方式影响该领域。首先，它将提供新的机制见解 T细胞功能障碍与HBV持续存在之间的关系，为未来的研究奠定坚实的基础 使用 AAV-HBV 模型更好地了解在人类中观察到的病毒与宿主的相互作用。第二， 它将揭示新的免疫治疗靶点，为治愈慢性乙型肝炎病毒感染的潜在方法提供依据。