Innate immunity to adenovirus

描述：腺病毒载体（Ad）是美国临床试验中第二常用的载体，用于治疗许多先天性和获得性人类疾病。尽管野生型Ad的自然感染在人类中基本上是无害的，但以基因传递为目的的静脉注射Ad，尤其是高剂量的静脉注射，会刺激强烈的先天免疫和炎症宿主反应。利用完全在体内的方法和大量基因缺陷小鼠模型，PI实验室发现血液中的Ad载体结合凝血因子，促进先天免疫受体对病毒的识别，并激活IL-1家族细胞因子，进而引发先天免疫和全身炎症的细胞和分子效应级联。最近，我们发现Ad可触发肝脏巨噬细胞（Kupffer细胞）的一种新型坏死样细胞死亡，其机制受干扰素调节因子3 （IRF3）控制。重要的是，除了Ad载体外，在将细菌病原体L.monocytogenes和完全合成的纳米颗粒注入小鼠血管内后，也观察到这种快速坏死的Kupffer细胞死亡。我们对播散性感染动物模型的初步研究表明，IRF3依赖性巨噬细胞坏死具有高度促炎作用，并导致白细胞减少，这是全身性炎症的临床症状。本项目的主要目标是：1)确定激活IRF3的分子机制和信号伙伴，以在体内执行坏死巨噬细胞死亡；2)在一种新型人源化小鼠模型中确定基因转移载体的先天免疫和炎症反应。这些目标将通过以下具体目标实现：鉴定IRF3修饰的分子特征及其在体内对Ad的反应中作为坏死性库普弗细胞死亡触发器的功能。2. 在体内鉴定针对IRF3执行坏死性Kupffer细胞死亡的信号通路成分。3. 在一种新的人源化小鼠模型中定义先天免疫激活和系统性先天免疫和炎症反应对基因转移载体的特征。从提出的研究中获得的概念和机制进展有可能极大地提高我们对Ad与宿主细胞在体内相互作用的理解，为与促炎抗病原体反应相关的基本细胞和分子生物学过程提供新的见解，并将允许优化疫苗接种和基因转移应用的基因转移载体。

DESCRIPTION: Adenovirus vectors (Ad) are the second most frequently used vectors in clinical trials in the US to treat numerous inborn and acquired human diseases. Even though natural infections with wild-type Ad are largely harmless in humans, an intravenous Ad administration for gene delivery purposes, especially at high doses, stimulates strong innate immune and inflammatory host responses. Using an entirely in vivo approach and a large collection of gene-deficient mouse models, the PI's laboratory has discovered that Ad vectors in the blood bind coagulation factors that facilitate virus recognition by innate immune receptors and activate IL-1 family cytokines, which, in turn, trigger a cascade of cellular and molecular effectors of innate immunity and systemic inflammation. Most recently, we found that Ad administration triggers a novel necrosis-like type of cell death of liver residential macrophages, Kupffer cells, that is mechanistically controlled by interferon regulatory factor 3, IRF3. Importantly, in addition to Ad vectors, this rapid necrotic Kupffer cell death was also observed after intravascular delivery into mice of both the bacterial pathogen L.monocytogenes and fully synthetic nanoparticles. Our preliminary studies in animal models of disseminated infections revealed that IRF3- dependent macrophage necrosis is highly pro-inflammatory and contributes to leukocytopenia, a clinical sign of systemic inflammation. The major goals of this grant proposal are i) to define the molecular mechanism and signaling partners that activate IRF3 to execute necrotic macrophage cell death in vivo and ii) to define the innate immune and inflammatory responses to gene transfer vectors in a novel humanized mouse model. These goals will be achieved via the following Specific Aims: 1. To identify the molecular signature of IRF3 modification(s) associated with its function as a trigger of necrotic Kupffer cell death in response to Ad in vivo. 2. To identify components of the signaling pathway that target IRF3 for execution of necrotic Kupffer cell death in vivo. 3. To define the signature of innate immune activation and systemic innate immune and inflammatory responses to gene transfer vectors in a novel humanized mouse model. The conceptual and mechanistic advances obtained from the proposed studies have the potential to greatly improve our understanding of Ad interactions with host cells in vivo, provide new insights into fundamental cell and molecular biological processes related to pro-inflammatory anti-pathogen responses, and will allow for optimization of gene transfer vectors for vaccination and gene transfer applications.