Inhibition of Liver Macrophage activation in SIV infected macaques

描述（由申请人提供）：HIV在全身多个组织部位引起不同的病理学和免疫失调。虽然HIV病毒本身启动了这些事件，但在HIV感染者中观察到的全身免疫激活的长期状态可能驱动了大部分观察到的免疫功能障碍。在肠道相关淋巴组织（GALT）中，HIV介导关键免疫细胞的损失/功能障碍，导致血液中细菌产物水平增加，这有助于持续的免疫超活化。巨噬细胞通过Toll样受体（TLR）检测微生物产物的关键作用及其产生参与免疫应答激活的细胞因子的能力使这些细胞可能是这种免疫病理学中的关键参与者。特别是，枯否细胞是肝脏巨噬细胞，它将首先遇到穿过肠粘膜（通过门静脉）的任何细菌产物，该提案的主要重点是研究枯否细胞功能障碍导致细菌产物和炎性细胞因子水平升高的可能性。猴免疫缺陷病毒（SIV）-猕猴模型已被用于通过鉴定与库普弗细胞增生肥大、多核巨细胞形成和炎性细胞因子产生相关的病毒蛋白来深入了解库普弗细胞功能。在本提案中，我们将联合收割机结合了两个实验室的各自优势，Sodora实验室具有SIV非人灵长类动物模型的专业知识，Crispe实验室具有肝脏免疫学的专业知识。我们将重点关注位于肝窦的枯否细胞床，因为这些是第一批看到门静脉细菌产物并产生炎性细胞因子的先天免疫细胞。我们推测，系统性免疫激活的结果，部分从生产的炎症细胞因子的肝脏巨噬细胞（枯否细胞）。治疗性控制枯否细胞的炎症反应可以降低猪尾猕猴的全身免疫激活水平和SIV疾病进展的迹象。我们的第一个目标是评估未感染与SIV感染的猪尾猕猴尸检时获得的肝枯否细胞的活化状态。我们的第二个目标将通过利用NF-kB抑制剂抑制猪尾猕猴的枯否细胞中的这种炎症反应来机械地评估NF-kB途径（由病毒和细菌产物刺激）的作用。CAPE（咖啡酸苯乙酯）防止NF-κ B易位到细胞核，并且注入聚缩酮颗粒中的CAPE优先被枯否细胞摄取。这些研究建立在 Crispe博士实验室利用CAPE-聚缩酮颗粒评估小鼠枯否细胞功能的工作。这个探索性的R21旨在提供深入研究领域的肝脏和枯否细胞生物学方面的SIV发病机制。通过抑制SIV-猕猴模型中的肝巨噬细胞活化，我们将确定靶向肝巨噬细胞是否是HIV感染患者免疫治疗的潜在策略。

DESCRIPTION (provided by applicant): HIV causes distinct pathology and immunologic dysregulation at multiple tissue sites throughout the body. While HIV virus itself initiates these events the prolonged state of systemic immune activation seen in HIV- infected individuals likely drives much of the observed immune dysfunction. Within gut associated lymphoid tissue (GALT), HIV mediates the loss/dysfunction of key immune cells leading to increased levels of bacterial products in the blood, which contribute to the sustained immune hyper-activation. The key role of macrophages for detecting microbial products via toll-like receptors (TLRs) and their ability to produce cytokines involved in activation of immune responses make these cells likely key players in this immune pathology. In particular, Kupffer cells are liver macrophages that will be the first to encounter any bacterial products that traverse the gut mucosa (via the portal vein), and the major focus of this proposal will be to investigate the potential for Kupffer cell dysfunction to contribute to the elevated levels of bacterial products and inflammatory cytokines. The simian immunodeficiency virus (SIV)-macaque model has been utilized to provide insights into Kupffer cell function through the identification of viral proteins associated with hyperplasia hypertrophy, multinuclear giant cell formation and inflammatory cytokine production of Kupffer cells. In this proposal we combine the individual strengths of two laboratories, the Sodora laboratory with expertise in SIV non-human primate models and the Crispe laboratory with expertise in liver immunology. We will focus on the Kupffer cell bed located in the sinusoids of the liver, as these are the first population of innate immune cells to see portal vein bacterial products, and produce inflammatory cytokines. We hypothesize that systemic immune activation results in part from the production of inflammatory cytokines by liver macrophages (Kupffer cells). And that therapeutic control of the inflammatory response of Kupffer cells can reduce the level of systemic immune activation and signs of SIV disease progression in pigtail macaques. Our first aim will assess the activation state of liver Kupffer cells obtained at necropsy from uninfected versus SIV infected pigtail macaques. Our second aim will mechanistically assess the role of the NF-kB pathway (stimulated by viral and bacterial products) by suppressing this inflammatory response in Kupffer cells of pigtail macaques utilizing an NF-kB inhibitor. CAPE (Caffeic Acid Phenethylester) prevents the translocation of NF-kB to the nucleus and CAPE infused in polyketal particles are preferentially taken up by Kupffer cells. These studies build on work by Dr. Crispe's laboratory utilizing CAPE-polyketal particles to assess Kupffer cell function of mice. This exploratory R21 is designed to provide insights into the understudied field of liver and Kupffer cell biology with regard to SIV pathogenesis. Through an inhibition of liver macrophage activation in the SIV- macaque model, we will determine if targeting liver macrophages is a potential strategy for immunotherapy in HIV-infected patients.