Novel Aspects of Hepatic Innate and Adaptive Immunity to HCV Infection

全世界约有2亿慢性丙型肝炎病毒(HCV)感染者。丙型肝炎病毒 肝癌的主要病因和肝移植的适应症。加深对丙型肝炎病毒宿主的认识 相互作用和调节肝脏内免疫的机制是对抗这种病毒和 开发改进的治疗方法。我们的实验室致力于了解先天免疫细胞的作用 如树突状细胞和自然杀伤细胞，以及由CD4和CD8T细胞介导的获得性免疫。 最近，我们的实验室对肝窦内皮细胞(LSECs)产生了兴趣，它是一种高度 常见于肝脏。尽管LSEC介导的抑制对于控制炎症至关重要，但它很可能 损害了对丙型肝炎病毒感染的保护性免疫。令人惊讶的是，对丙型肝炎病毒中的LSECs知之甚少 感染。我们将使用包括LSEC、肝细胞和T细胞在内的人类来源样本的组合， 以及多细胞模型中的药理和沉默策略。 在这一新的应用中，我们将确定人肝窦对丙型肝炎病毒传感的不同效果。 内皮细胞(LSECs)抗病毒干扰素信号转导。我们假设丙型肝炎病毒采用多种策略来 靶向LSECs，包括直接感染、吞噬作用或与核心等丙型肝炎病毒特异性蛋白的结合。这个 感染丙型肝炎病毒的肝细胞凋亡的摄取或炎症状态的增强可能调节 病毒或运输受体的表达可能最终在丙型肝炎病毒中发挥保护或不利作用 在肝脏内扩散。此外，我们将描述增强或拮抗的机制 LSEC衍生因子在原代和永生化肝细胞中抑制病毒复制的能力 I型和III型干扰素的作用，以及调节IL-28B(干扰素-3)诱导的转录元件 LSEC。了解丙型肝炎病毒与LSECs相互作用的多种方式来调节 抗病毒细胞因子，如干扰素，所涉及的特定细胞内信号通路，以及在 肝窦微环境最终将提供新的机制洞察力和潜力 针对这种常见感染的治疗靶点。我们还将定义丙型肝炎病毒- 经验丰富的LSEC诱导调节性CD4T细胞表型并损害CTL的功能，识别 逆转这种抑制的机制，以增强抗病毒免疫。到目前为止，我们发现 LSEC通过丙型肝炎病毒核心蛋白上调Galectin-9和活性氧物种。目标的完成 在本申请中概述的将通过链接固有的LSec功能最终在该领域中提供垂直步骤 控制获得性免疫。

Approximately 200 million throughout the world have chronic hepatitis C viral (HCV) infection. HCV is leading cause of liver cancer and indication for liver transplantation. Enhanced understanding of HCV-host interactions and the mechanisms that regulate immunity within the liver is required to combat this virus and to develop improved therapies. Our laboratory has focused on understanding the role of innate immune cells such as dendritic and natural killer cells, as well as adaptive immunity mediated by CD4+ and CD8+ T cells. Recently our laboratory has become interested in liver sinusoidal endothelial cells (LSECs) which are highly frequent in the liver. Although LSEC-mediated suppression is critical for control of inflammation, it likely compromises protective immunity against HCV infection. Surprisingly little is known about LSECs in HCV infection. We will use a combination of human derived specimens, including LSECs, hepatocytes, and T cells, as well as pharmacologic and silencing strategies in multi-cellular models. In this new application, we will determine the differential effects of HCV sensing by human liver sinusoidal endothelial cells (LSECs) on antiviral IFN signaling. We hypothesize that HCV employs multiple strategies to target LSECs, including direct infection, pinocytosis, or binding of HCV-specific proteins such as core. The uptake of apoptotic HCV-infected hepatocytes or enhancement of an inflammatory state that may regulate the expression of viral or trafficking receptors may ultimately play either protective or adverse roles in HCV dissemination within the liver. In addition, we will characterize the mechanisms that enhance or antagonize LSEC-derived factors' ability to inhibit viral replication in primary and immortalized hepatocytes, the autocrine effects of Type I and III IFNs, and the transcriptional elements that regulate IL-28B (IFN- 3) induction within LSECs. Understanding the multiple ways in which HCV interacts with LSECs to modulate the production of antiviral cytokines such as IFNs, the specific intracellular signaling pathways involved, as well as effects within the hepatic sinusoidal microenvironment will ultimately provide novel mechanistic insights and potential therapeutic targets for this common infection. We will also define the specific processes whereby HCV- experienced LSECs induce a regulatory CD4+ T cell phenotype and impair function of CTLs, identifying mechanisms to reverse this suppression in order to enhance anti-viral immunity. To date, we have found that LSECs upregulate Galectin-9 and reactive oxygen species with HCV core protein. Completion of the aims outlined in this application would ultimately provide a vertical step in the field by linking innate LSEC function to control of adaptive immunity.