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 很少有病毒能够在人类身上表现为慢性感染。先天免疫反应 提供了抵御入侵病毒的第一道防线；然而，对于慢性病毒感染，这些 在控制病毒复制方面无效的最初反应可能会在多年后导致疾病 由于慢性激活。在大多数器官中，上皮细胞是第一批在体内遇到病毒的细胞 人体和这些细胞中的先天免疫反应是推动后续免疫的重要因素 控制力。有趣的是，上皮细胞主要产生III型干扰素(IFN)来响应病毒 而免疫细胞产生II型IFN(γ)和I型IFN(α/β)是由大多数细胞在 身体。III型IFN的细胞类型和组织特异性表达的潜在机制尚不清楚 可能涉及表观遗传修饰、模式识别受体的基因表达和 相关的信号分子。在果蝇中，脂肪体是产生 对病原体作出反应的抗菌肽。人的肝脏，相当于果蝇的脂肪体中 在功能方面，利用III型干扰素反应来对抗病毒感染，并可能拥有其他独特的 与生俱来的免疫力与其他器官相比的特性我们开发了小说和 激动人心的体外模型，利用几个器官的原代上皮细胞，这些器官具有完整的天然免疫 与永生化或转化的细胞系比较时的反应。我们和其他人已经证明了这些细胞 类型在疾病的发展中至关重要，因为它们直接检测到病毒的成分 病原体。因此，我们断言原代细胞是研究先天免疫的最佳模型。 我们提出了一种基于先天免疫途径的研究先天免疫的新方法 已被证明在微生物发病机制中具有重要作用。此外，我们正在开发新的 融合原代上皮细胞、干细胞来源的上皮细胞、三维芯片的生理学模型 以及基于微流控技术的平台。干细胞来源的细胞的使用将有助于识别 基因表达的变化，发生在分化过程中，有助于独特的先天免疫 上皮细胞中的系统。这个计划的具体目标是从功能上刻画先天的 免疫反应，包括产生III型IFN，对多种病毒病原体相关模式， 包括DNA和RNA传感通路，并阐明其潜在的分子机制 通过它，使用复杂的体外模型，在上皮细胞中表现出先天免疫。此外, 特定先天免疫信号成分的组织特异性和发育表达，包括， TLR3，STING和IRF7，将作为组织特异性反应的基础机制。完成 这些研究将为上皮细胞和其他细胞的天然免疫提供最深入的表征- 同时提高我们对其在多个器官中对人类疾病的贡献的理解。

Project Abstract Very few viruses are able to manifest as chronic infections in humans. The intrinsic innate immune response provides a first line of defense against invading viruses; however, in the case of chronic viral infections, these initial responses that were ineffective at controlling virus replication can then cause disease over many years due to chronic activation. In most organs, epithelial cells are some of the first cells to encounter viruses in the human body and innate immune responses in these cells are paramount to driving subsequent immune control. Interestingly, epithelial cells predominantly produce type III interferons (IFNs) in response to viral infection whereas immune cells produce Type II IFNs (γ) and Type I IFNs (α/β) are produced by most cells in the body. The mechanism underlying cell type and tissue specific expression of the type III IFNs are unknown and likely involve regulation of epigenetics modifications, gene expression of pattern recognition receptors and associated signaling molecules. In drosophila, the fat body is the primary innate immune organ producing antimicrobial peptides in response to pathogens. The human liver, equivalent to the drosophila fat body in terms of function, utilizes Type III IFN responses to fight viral infection and likely possesses other unique properties with respect to innate immunity when compared to other organs. We have developed novel and exciting in vitro models that utilize primary epithelial cells from several organs that have intact innate immune responses when compared to immortalized or transformed cell lines. We and others have shown that these cell types 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 study innate immunity based on the innate immune pathways that we have demonstrated to be important for microbial pathogenesis. In addition, we are developing novel physiologic models incorporating primary epithelial cells, stem cell-derived epithelial cells, 3-dimensional chip and microfluidic-based platforms. The use of stem cell-derived cells would facilitate the identification of changes in gene expression, 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, including the production of Type III IFNs, 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 in vitro models. In addition, tissue specific and developmental expression of specific innate immune signaling components including, TLR3, STING and IRF7, will be addressed as a mechanism underlying tissue specific responses. Completion of these studies would offer the most in depth characterization of innate immunity in epithelial and other cell- types while improving our understanding of its contribution to human disease in multiple organs.