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 很少有病毒能够表现为人类的慢性感染。内在先天免疫反应 提供了抵御入侵病毒的第一道防线;然而，在慢性病毒感染的情况下，这些 最初的反应在控制病毒复制方面无效，然后在许多年内引起疾病 由于慢性激活。在大多数器官中，上皮细胞是最先遇到病毒的细胞。 人体和这些细胞中的先天免疫应答对于驱动随后的免疫应答是至关重要的。 控制有趣的是，上皮细胞主要产生III型干扰素（IFN），以响应病毒感染。 尽管免疫细胞产生II型IFN（γ）和I型IFN（α/β），但大多数细胞在感染中产生IFN（γ）和I型IFN（α/β）。 身体III型IFN的细胞类型和组织特异性表达的机制尚不清楚 并且可能涉及表观遗传学修饰的调节、模式识别受体的基因表达以及 相关的信号分子。在果蝇中，脂肪体是主要的先天免疫器官， 抗微生物肽对病原体的反应。人类的肝脏相当于果蝇的脂肪体， 就功能而言，利用III型IFN应答来对抗病毒感染，并可能具有其他独特的 与其他器官相比，先天免疫的特性。我们开发了新颖的， 令人兴奋的体外模型，利用来自具有完整先天免疫的几个器官的原代上皮细胞， 与永生化或转化的细胞系相比，我们和其他人已经证明，这些细胞 类型在疾病的发展中至关重要，因为它们直接检测病毒的成分， 病原体因此，我们认为原代细胞是研究先天免疫的最佳模型 我们提出了一种新的方法来研究先天免疫的基础上先天免疫途径，我们 已经证明对微生物的致病性很重要。此外，我们正在开发新的 包含原代上皮细胞、干细胞衍生的上皮细胞、三维芯片的生理模型 和基于微流体的平台使用干细胞衍生的细胞将有助于鉴定 在分化过程中发生的基因表达的变化，有助于独特的先天免疫， 上皮细胞的系统。该计划的具体目标是在功能上表征先天性 对多种病毒病原体相关模式的免疫应答，包括III型IFN的产生， 包括DNA和RNA传感途径，并阐明潜在的分子机制 先天免疫通过复杂的体外模型在上皮细胞中显现。此外，本发明还提供了一种方法， 特异性先天免疫信号传导组分的组织特异性和发育表达， TLR 3、STING和IRF 7将作为组织特异性应答的潜在机制来解决。完成 这些研究将提供上皮和其他细胞中先天免疫的最深入表征， 类型，同时提高我们对它在多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.