Markers and regulation of regulatory CD8+ T cells during influenza-induced lung immunopathology

项目摘要/摘要 流感(流感)感染是世界上呼吸系统疾病和相关死亡的主要原因。 据估计，每年的流感流行导致300-500万例严重疾病和超过25万人 死亡。清除病毒需要很强的效应器免疫，但如果不这样做，可能会导致免疫病理 控制得当。严重和致命的流感疾病伴随着一种侵略性的促炎 反应和抗炎免疫力不足。免疫调节细胞因子IL-2的产生 10由流感特异性CD8+T细胞在限制肺部感染期间的免疫病理过程中起关键作用，有助于 宿主存活和恢复。了解如何识别这些调节性CD8+T细胞，并了解它们是如何 发育和功能对于学习如何控制流感诱导的肺免疫病理是必不可少的。这使得 我们的工作意义重大。虽然对CD4+调节性T细胞的了解很多，但分子签名 而且调节IL-10+调节性CD8+T细胞的发育和功能的机制仍然很差 理解，特别是在流感引起的呼吸道炎症的背景下。我们最近产生了一种IL- 10GFP/Foxp3RFP双报告小鼠模型，能够检测活细胞中的IL-10和Foxp3，以及 在正常和肺组织中进行IL-10+和/或Foxp3+T细胞的筛查 炎症状态。我们发现Foxp3-IL-10+CD8+T细胞存在于各种器官和疾病中 在流感感染期间，它们是呼吸道产生IL-10的主要因素。这些 Foxp3-IL-10+CD8+T细胞对先天致炎和 适应性免疫反应，预示着一种治疗潜力。然而，目前还没有可靠的标记物 Foxp3-IL-10+CD8+调节性T细胞。我们假设分子签名和相关路径 随着产生IL-10的调节性CD8+T细胞的发展和功能的发挥，可以利用它们来 制定针对流感引起的肺部免疫病理的治疗策略。我们的预赛 研究鉴定了一种新的表面标志LAG3hiCD25hiBTLAloCD226lo及其关键转录 流感感染过程中IL-10+CD8+T细胞中TCF1因子的变化我们建议在两个具体目标下进行实验： (1)确定和验证产生IL-10的调节性CD8+T细胞的表面标志物；以及(2) 确定TCF1在产生IL-10的调节性CD8+T细胞发育和功能中的作用。这项工作是 高度创新，因为我们利用全面的生化、遗传和基因组学方法 转基因小鼠模型，并有令人兴奋的初步数据，可以扩展以提供信息 表面标记和关键信号通路，以更好地了解发育和 流感感染过程中产生IL-10的CD8+T细胞的免疫调节功能我们期待着解体 可以更好地控制流感诱导的致病机制的潜在分子机制，可能 提高我们制定控制病毒引起的免疫病理、发病率和死亡率的战略的能力。

Project Summary/Abstract Influenza (Flu) infection is a leading cause of respiratory disease and associated death in the world. The annual flu epidemics are estimated to result in 3-5 million cases of severe illness and more than 250,000 deaths. A strong effector immunity is desired for viral clearance, it however can lead to immunopathology if not properly controlled. Severe and fatal influenza diseases are accompanied by an aggressive pro-inflammatory response and an insufficient anti-inflammatory immunity. The production of the immunoregulatory cytokine IL- 10 by flu-specific CD8+ T cells is critical in limiting the lung immunopathology during infection, contributing to host survival and recovery. Knowing how to identify these regulatory CD8+ T cells and understanding how they develop and function are essential for learning how to control flu-induced lung immunopathology. This makes our work highly significant. While much is known about the CD4+ regulatory T cells, the molecular signature and mechanisms that regulate the development and function of IL-10+ regulatory CD8+ T cells remain poorly understood, particularly in the context of influenza-induced airway inflammation. We recently generated an IL- 10GFP/Foxp3RFP dual reporter mouse model that enables detection of IL-10 and Foxp3 in live cells, and undertook a screening for the presence of IL-10+ and/or Foxp3+ T cells under normal and pulmonary inflammatory conditions. We found that Foxp3- IL-10+ CD8+ T cells are present in various organs and disease conditions, and are the major contributors to IL-10 production in the airway during influenza infection. These Foxp3- IL-10+ CD8+ T cells exhibit profound immunoregulatory function against pro-inflammatory innate and adaptive immune responses, indicative of a therapeutic potential. There are however no reliable markers for Foxp3- IL-10+ CD8+ regulatory T cells. We hypothesize that molecular signatures and pathways associated with the development and function of IL-10-producing regulatory CD8+ T cells can be exploited to develop therapeutic strategies against influenza-induced lung immunopathology. Our preliminary studies identified a novel surface signature LAG3hiCD25hiBTLAloCD226lo and the critical transcription factor TCF1 in IL-10+ CD8+ T cells during influenza infection. We propose experiments in two Specific Aims to: (1) determine and validate signature surface markers of IL-10-producing regulatory CD8+ T cells; and (2) determine the role of TCF1 in IL-10-producing regulatory CD8+ T cell development and function. This work is highly innovative as we utilize comprehensive biochemical, genetic and genomics approaches with unique transgenic mouse models, and have exciting preliminary data that can be expanded to provide information of surface markers and critical signaling pathways for a better understanding of the development and immunoregulatory function of IL-10-producing CD8+ T cells during Influenza infection. We expect to unravel potential molecular mechanisms through which flu-induced pathogenesis can be better controlled, which may enhance our ability of developing strategies to control virus-induced immunopathology, morbidity and mortality.