Molecular Mechanisms Underlying Dendritic Cell Adaptations During Chronic Infection

摘要 慢性病毒感染代表了一个主要的生物医学问题，其特征在于长期的病毒感染。 病原体和免疫系统之间的平衡。这种平衡是通过适应 免疫细胞，其减弱选定的免疫功能以使免疫病理学最小化，同时保持 病原体检查完毕类似的免疫适应可以检测到（往往是以短暂的方式）急性 感染，但只是持续和相关的病原体持久性在慢性感染。因此，在本发明中， 在慢性感染的背景下研究免疫细胞适应的潜在机制， 揭示了免疫系统的新的基础生物学，但也可以解锁新的治疗策略， 持续感染的人。这是最好的例证，发现T细胞耗竭和他们的免疫反应。 在淋巴细胞性脉络丛脑膜炎病毒（LCMV）感染期间， 这两个发现被扩展到人类的许多感染以及癌症， 自身免疫性疾病此外，我们和其他人已经确定，树突状细胞（DC），发挥中央 在免疫中的作用，也适应在慢性病毒感染的背景下，显示出受损的发展， 骨髓祖细胞、次优成熟和改变的细胞因子产生。 为了了解DC及其祖细胞适应的机制，我们应用了切割- 边缘生物信息学方法分析LCMV DC祖细胞的转录组和表观基因组 感染的小鼠，并预测几种转录因子（TF）的活性改变。其中，我们发现， 糖皮质激素调节元件结合蛋白1（Gmeb 1）抑制DC发育， 成熟，而锌指蛋白524（Zfp 524）在体外调节细胞因子的产生。这些结果提供 这表明Gmeb 1和Zfp 524对改善我们对DC生物学的基本理解具有特殊的前景。 我们建议利用慢性LCMV过程中成熟和持续的DC适应 感染，以进一步探索Gmeb 1和Zfp 524的新作用和潜在机制。为此，在 我们计划在体外和体内完全确定Gmeb 1（Aim 1）和Zfp 524（Aim 2）的作用， 未感染和LCMV感染的小鼠以及人DC中。我们将确定他们的下游目标 基因，并研究这些TF在DC调节中的作用如何与Gmeb 1的已知功能相关， 增强子的糖皮质激素驱动的基因表达，并推定的调控Zfp 524表达的芳基- 烃受体最后，我们将研究Gmeb 1和Zfp 524的直流调节与这些作用的关系， I型干扰素和Toll样受体-7，我们报告的DC适应慢性LCMV感染后。 我们的研究将使用尖端技术来揭示DCs的分子机制， 在体内慢性病毒感染的情况下调节。这将大大增加我们的基本知识 并揭示了新的治疗靶点，以利用感染性和非感染性疾病的DC。

ABSTRACT Chronic viral infections represent a major biomedical problem and are characterized by a long-term equilibrium between the pathogen and the immune system. Such equilibrium is enabled by adaptations of immune cells that attenuate selected immune functions to minimize immunopathology while keeping the pathogen in check. Similar immune-adaptations may be detected (often in a transient manner) after acute infections but are only sustained and relevant for pathogen persistence during chronic infections. Thus, studying the mechanisms underlying immune cell adaptations in the context of chronic infections may not only unveil new basic biology of the immune system but could also unlock new therapeutic strategies for alleviating persistently infected individuals. This is best exemplified by the discovery of T cell exhaustion and their inhibition via the inhibitory receptor PD1 during lymphocytic choriomeningitis virus (LCMV) infection in its natural murine host, two findings that were extended to many infections in humans as well as cancer and autoimmune diseases. In addition, we and others have established that Dendritic Cells (DC), which play central roles in immunity, also adapt in the context of chronic viral infections, showing compromised development from bone marrow progenitors, suboptimal maturation and altered cytokine production. To understand the mechanisms underlying DC and their progenitor adaptations, we applied a cutting- edge bioinformatic approach to analyze the transcriptome and epigenome of DC progenitors from LCMV infected mice, and predicted altered activity of several transcription factors (TFs). Among them, we revealed that Glucocorticoid Modulatory Element Binding Protein 1 (Gmeb1) suppresses DC development and maturation while Zinc Finger Protein 524 (Zfp524) regulates cytokine production in vitro. These results provide evidence that Gmeb1 and Zfp524 hold exceptional promise to improve our basic understanding of DC biology. We propose to take advantage of the well-established and sustained DC adaptations during chronic LCMV infection to further explore the novel roles and underlying mechanisms of Gmeb1 and Zfp524. For that, in Aim#1 and #2 we plan to fully establish the roles of Gmeb1 (Aim1) and Zfp524 (Aim 2) in vitro and in vivo, in both uninfected and LCMV infected mice as well as in human DCs. We will determine their downstream target genes and investigate how these TFs' roles on DC regulation relates to the known function of Gmeb1 as an enhancer of glucocorticoid driven gene expression, and to the putative regulation of Zfp524 expression by Aryl- hydrocarbon receptor. Finally, we will study the relationship of Gmeb1 and Zfp524 DC regulation with the roles of type-I-interferons and toll-like-receptor-7 that we reported for DC adaptations after chronic LCMV infection. Our studies will use cutting-edge technology to unveil the molecular mechanisms by which DCs are regulated in the context of a chronic viral infection in vivo. This will significantly increase our basic knowledge of DC biology and unveil new therapeutic targets to harness DCs in infectious and non-infectious diseases.