A Multifaceted Approach to Study Tissue and Cell Type Specific Molecular Mechanisms of the Host Response to Acute/Chronic Viral Infection

项目摘要 很少有病毒在人类中表现为致病性慢性感染，大多数被急性清除。牢房- 内在的先天性抗病毒反应提供了抵抗入侵病毒的第一道防线。可惜在 在慢性病毒感染的情况下，这些在控制病毒复制方面无效的初始反应可以 随后由于慢性炎症而引起疾病。在大多数器官中，上皮细胞是最先 细胞遇到病毒和这些细胞中的宿主防御反应对于促进病毒根除是至关重要的。 有趣的是，上皮细胞主要产生III型干扰素（IFN）响应病毒感染 而免疫细胞产生II型（γ），而I型（α/β）IFN由体内大多数细胞产生。的 IFN的细胞类型和器官特异性表达的潜在机制尚不清楚，可能涉及 表观遗传修饰（例如SOCS 1）的调节，模式识别受体（例如TLR 3， cGAS）、相关信号分子（例如STING）和相关转录因子（例如IRF 7）。在果蝇中， 脂肪体是响应病原体产生抗微生物肽的先天免疫器官。在人类中， 肝脏在功能上等同于果蝇脂肪体，同时利用III型IFN应答来对抗病毒， 感染，它可能具有其他独特的性质，就先天免疫相比，其他 机关我们已经开发了严格的，新颖的和令人兴奋的体外模型，利用原代上皮细胞从 与永生化或转化细胞相比，几个器官具有完整的先天抗病毒反应 线我们和其他人已经证明这些细胞在疾病的发展中至关重要 因为它们直接检测病毒病原体的成分。因此，我们断言，原代细胞是最佳的 模型用于先天免疫的研究，我们提出了一种新的方法来严格研究这一基础上， 我们已经证明的信号通路对病毒清除和发病机制很重要。在 此外，我们已经开发了新的模型，其结合了原代上皮细胞、iPSC衍生的上皮细胞和 3-三维芯片和基于微流体的平台，用于涉及多种细胞类型的研究。使用iPSC- 衍生的细胞有助于鉴定基因表达和表观遗传或翻译后的变化， 在分化过程中发生的修饰，有助于上皮细胞中独特的先天免疫系统， 细胞该计划的具体目标是从功能上表征先天免疫反应， 病毒病原体相关模式，包括DNA和RNA传感途径，并阐明 先天免疫通过复杂的分子机制在上皮细胞中表现出来， 模型此外，器官特异性和相关的发育变化的功能表达， 具体的信号通路将通过研究组织特异性的表观遗传机制来解决。 抗病毒反应。完成这些雄心勃勃的研究将提供深入的先天性特征， 它不仅有助于增强免疫力，同时使我们能够开发其对人类多器官疾病的贡献的新范例。

Project Abstract Very few viruses manifest as pathogenic chronic infections in humans and most are cleared acutely. The cell- intrinsic innate antiviral response provides a first line of defense against invading viruses. Unfortunately, in the case of chronic viral infections, these initial responses that were ineffective at controlling virus replication can subsequently cause disease due to chronic inflammation. In most organs, epithelial cells are some of the first cells to encounter viruses and host defense responses in these cells are paramount to facilitating viral eradication. Interestingly, epithelial cells predominantly produce type III interferons (IFNs) in response to viral infection whereas immune cells produce Type II (γ) while Type I (α/β) IFNs are produced by most cells in the body. The mechanism underlying cell type and organ specific expression of the IFNs are unknown and likely involve regulation of epigenetic modifications (e.g. SOCS1), gene expression of pattern recognition receptors (e.g. TLR3, cGAS), associated signaling molecules (e.g. STING) and pertinent transcription factors (e.g. IRF7). In drosophila, the fat body is the innate immune organ producing antimicrobial peptides in response to pathogens. In humans, the liver is functionally equivalent to the drosophila fat body while utilizing Type III IFN responses to fight viral infection and it likely possesses other unique properties with respect to innate immunity when compared to other organs. We have developed rigorous, novel and exciting in vitro models that utilize primary epithelial cells from several organs that have intact innate antiviral responses when compared to immortalized or transformed cell lines. We and others have demonstrated that these cells are of critical importance in the development of disease since they directly detect components of viral pathogens. We therefore assert that primary cells are the optimal model to use for studies on innate immunity and we propose a novel approach to rigorously study this based on the signaling pathways that we have demonstrated to be important for viral clearance and pathogenesis. In addition, we have developed novel models incorporating primary epithelial cells, iPSC-derived epithelial cells and 3-dimensional chip and microfluidic-based platforms for studies involving multiple cell types. The use of iPSC- derived cells facilitates the identification of changes in gene expression and epigenetic or post-translational modifications, which occur during differentiation, that contribute to the unique innate immune system in epithelial cells. The specific goals of this program are to functionally characterize the innate immune response, to multiple viral pathogen associated patterns including both DNA and RNA sensing pathways, and to elucidate the underlying molecular mechanisms through which innate immunity manifests in epithelial cells using sophisticated models. Furthermore, organ specific and associated developmental changes in the functional expression of specific signaling pathways will be addressed through studies on epigenetic mechanism underlying tissue specific antiviral responses. Completion of these ambitious studies would offer in depth characterization of innate immunity while allowing us to develop new paradigms for its contribution to human disease in multiple organs.