The Innate Immune Response in the Marmoset Model of GBV-B Infections: A Surrogate

GBV-B 感染狨猴模型中的先天免疫反应：替代

• 批准号: 8676647
• 负责人: Robert E LANFORD
• 金额: $ 55.27万
• 依托单位: TEXAS BIOMEDICAL RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-15 至 2016-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8676647
• 关键词: Address; Affect; Animal Model; Area; Biology; Callithrix; Cells; Characteristics; Chronic; Cirrhosis; Collaborations; Data; Dendritic Cells; Development; Disease Progression; Event; Failure; Feedback; GB virus B; Gene Expression; Gene Targeting; Genes; Genetic Polymorphism; Hepatitis; Hepatitis C; Hepatitis C virus; Hepatocyte; IFNAR1 gene; IRF3 gene; Immune response; Immune system; In Vitro; Individual; Infection; Interferons; Kinetics; Lead; Liver; Malignant neoplasm of liver; MicroRNAs; Modeling; Mus; Oligonucleotides; Outcome; Pan Genus; Pathway interactions; Patients; Peptide Hydrolases; Pharmaceutical Preparations; Phenotype; Play; Population; Primates; Production; Research; Research Project Grants; Role; Saguinus; Series; Source; Stimulus; System; TLR3 gene; TLR7 gene; Technology; Viral; Viral Load result; Viremia; Virus; Virus Activation; Virus Diseases; in vivo; innovation; locked nucleic acid; man; nonhuman primate; novel strategies; receptor; response; sensor; success; tissue culture; viral RNA

DESCRIPTION (provided by applicant): Hepatitis C virus infections affect approximately 2% of the population and often progress to cirrhosis and liver cancer. Some of the characteristics associated with a failed adaptive immune response in chronic infection have been identified, yet the events that precede and determine the failed immune response are less clear and may involve the innate immune response. Research on HCV has been impeded by the lack of a small animal model. In this proposal, we will use GBV-B infected marmosets in an innovative approach to evaluate knockdown of a series of target genes involved in the innate immune response. GBV-B is the virus most closely related to HCV and it induces hepatitis in marmosets and tamarins. The central hypothesis of this project is that the innate immune response is essential for limiting viral spread in the liver and for orchestrating the adaptive immune response for the successful clearance of infected cells. Knockdown of critical components of the innate response may lead to extended duration of viremia and potentially persistent infections. In collaboration with Santaris Pharma, we recently demonstrated the ability of systemically administered LNA (locked nucleic acid) oligos to knockdown genes in a primate model; the knockdown of microRNA-122 in chimpanzees effectively reduced HCV viral load. Chimpanzees are too large and expensive for use in most research projects. Marmosets are ideal for this project due to the small size and the fact that they normally clear GBV-B infection, one of the few differences from HCV. Persistent infections beyond one year have been observed, thus the capacity for persistence clearly exists. In aim 1, we will target miR122 using the same LNA antisense oligo as the Santaris drug, SPC3649. This will serve as a positive control to evaluate the kinetics and magnitude of LNA knockdown in the marmoset. In aim 2, we will knockdown IL28B and its receptor IL28RA. In man polymorphisms in IL28B are highly predictive of persistent infection with HCV, yet we have little understanding of how IL28B influences HCV infection. In aim 3, we will knockdown TLR7, the primary receptor on plasmacytoid dendritic cells sensing viral RNA and triggering IFN production. We will also knockdown BST2, the receptor that provides negative feedback to pDCs and controls IFN production. In aim 4, we will knockdown the sensors of viral RNA in the liver leading to IFN production including RIG-I, TLR3 and IRF3. Although, HCV protease subverts both these pathways, the role this plays in vivo in the spread of virus and induction of ISGs in the liver is poorly understood. Collectively, these studies will help define the role of various components of the innate immune response in viral clearance and potentially new approaches to therapies for chronic infections. In addition, persistent GBV-B infections would represent a new primate model for HCV disease progression. Furthermore, development of a primate model of targeted gene knockdown would be of great value in a number of research areas.

描述（由申请人提供）：丙型肝炎病毒感染影响大约 2% 的人口，并且经常进展为肝硬化和肝癌。与慢性感染中适应性免疫反应失败相关的一些特征已被确定，但先于并确定免疫反应失败的事件尚不明确，并且可能涉及先天免疫反应。由于缺乏小动物模型，HCV 研究受到阻碍。在本提案中，我们将采用创新方法使用 GBV-B 感染的狨猴来评估涉及先天免疫反应的一系列目标基因的敲除。 GBV-B 是与 HCV 最密切相关的病毒，它会诱发狨猴和狨猴的肝炎。该项目的中心假设是，先天免疫反应对于限制病毒在肝脏中的传播以及协调适应性免疫反应以成功清除受感染的细胞至关重要。先天反应的关键成分的敲低可能导致病毒血症持续时间延长和潜在的持续感染。我们最近与 Santaris Pharma 合作，证明了系统施用 LNA（锁核酸）寡核苷酸在灵长类动物模型中敲低基因的能力；黑猩猩体内 microRNA-122 的敲除有效降低了 HCV 病毒载量。黑猩猩体型太大且昂贵，不适合大多数研究项目。狨猴是该项目的理想选择，因为狨猴体型小，而且它们通常能清除 GBV-B 感染，这是与 HCV 的少数区别之一。已经观察到持续感染超过一年，因此明显存在持续感染的能力。在目标 1 中，我们将使用与 Santaris 药物 SPC3649 相同的 LNA 反义寡核苷酸来靶向 miR122。这将作为阳性对照来评估狨猴中 LNA 敲低的动力学和程度。在目标 2 中，我们将敲低 IL28B 及其受体 IL28RA。在人类中，IL28B 多态性高度预测 HCV 持续感染，但我们对 IL28B 如何影响 HCV 感染知之甚少。在目标 3 中，我们将敲除 TLR7，这是浆细胞样树突状细胞上感知病毒 RNA 并触发 IFN 产生的主要受体。我们还将敲除 BST2，这种受体向 pDC 提供负反馈并控制 IFN 的产生。在目标 4 中，我们将敲除肝脏中导致 IFN 产生的病毒 RNA 传感器，包括 RIG-I、TLR3 和 IRF3。尽管 HCV 蛋白酶破坏了这两种途径，但人们对其在体内病毒传播和肝脏 ISG 诱导中所起的作用知之甚少。总的来说，这些研究将有助于确定先天免疫反应的各个组成部分在病毒清除中的作用，以及慢性感染治疗的潜在新方法。此外，持续性 GBV-B 感染将代表 HCV 疾病进展的新灵长类动物模型。此外，开发靶向基因敲除的灵长类动物模型将在许多研究领域具有巨大价值。