Innate immunity to adenovirus vectors

描述（由申请人提供）：腺病毒载体（Ad）是全球临床研究中最常用的病毒载体类型。在血管内递送时，Ad引起多方面的宿主先天免疫和炎症反应，由于剂量有限的全身毒性，这极大地损害了基于Ad的治疗的安全性和有效性。控制这种系统性抗ad炎症反应的分子和细胞机制仍然知之甚少。通过分析将衣壳修饰的Ad载体注入敲除关键炎症介质的小鼠体内后引发的炎症，我们首次观察到Ad与23种整合素和巨噬细胞表面受体的相互作用触发了IL-11介导的独特炎症途径。该途径的激活启动下游细胞因子和趋化因子级联，依赖于功能性IL-1RI信号传导。然而，我们的研究还表明，除了这种细胞因子的产生，静脉注射Ad诱导促炎性MF快速死亡和促炎性白细胞涌入受影响部位。本提案的具体目的旨在确定静脉注射Ad后观察到的Ad诱导炎症的每种已知成分对临床相关全身毒性的贡献。在Specific Aim 1中，我们将研究ad诱导的促炎性巨噬细胞体内死亡的分子机制，以及它在激活全身抗ad炎症反应中的作用。在Specific Aim 2中，我们将分析静脉注射Ad后积聚在脾脏和肝脏中的炎性白细胞的表型标记物和功能激活状态，以及它们在介导急性全身抗Ad炎症反应中的作用。在Specific Aim 3中，我们将构建新的Ad载体，避免与23种整合素相互作用，并分析它们在体内的基因传递和全身毒性。这些研究将提高我们对宿主防御病毒病原体的基本机制的理解，并可能最终导致开发安全有效的Ad载体，用于治疗广泛的先天性和获得性人类疾病。

DESCRIPTION (provided by applicant): Adenovirus vectors (Ad) are the most common viral vector type used in clinical studies worldwide. Upon intravascular delivery, Ad elicits multifaceted host innate immune and inflammatory responses that drastically compromise both the safety and the efficacy of the Ad-based therapy due to a dose-limiting systemic toxicity. The molecular and cellular mechanisms governing this systemic anti-Ad inflammatory response remain poorly understood. By analyzing the initiation of inflammation in vivo after the injection of capsid-modified Ad vectors into mice knockout for critical inflammatory mediators, we have made an original observation that Ad interaction with 23 integrins and macrophage cell-surface receptors triggers a unique inflammatory pathway mediated by IL-11. Activation of this pathway initiates a downstream cytokine and chemokine cascade that depends on functional IL-1RI signaling. However, our studies also indicate that, in addition to this cytokine production, intravenous Ad administration induces a rapid pro-inflammatory MF death and the influx of pro-inflammatory leukocytes into affected sites. The Specific Aims of this proposal are designed to define the contribution of each of the known components of Ad-induced inflammation into the clinically relevant systemic toxicity observed after the intravenous Ad administration. In Specific Aim 1, we will investigate the molecular mechanisms involved in mediating Ad-induced pro- inflammatory macrophage cell death in vivo, and its role in activating systemic anti-Ad inflammatory response. In Specific Aim 2, we will analyze the phenotypic markers and functional activation states of inflammatory leukocytes, accumulating in the spleen and liver after intravenous Ad injection, and their role in mediating the acute systemic anti-Ad inflammatory response. In Specific Aim 3, we will construct novel Ad vectors that would avoid interaction with 23 integrins and analyze their gene delivery and systemic toxicity profiles in vivo. These studies will improve our understanding of the fundamental mechanisms of host defense against viral pathogens and may ultimately lead to the development of safe and effective Ad vectors for the therapy of a wide range of inborn and acquired human diseases. PUBLIC HEALTH RELEVANCE: Adenovirus vectors (Ad) are the most common viral vector type used in clinical studies worldwide. Despite extensive preclinical data on the use of Ad in gene transfer applications, Ad's use for gene therapy in humans is severely limited due to life-threatening innate immune and inflammatory responses that arise after intravascular delivery of the high (and potentially therapeutic) virus doses. This proposal is to fill the major void in our understanding of Ad-induced inflammation in vivo triggered after intravascular virus delivery. These studies will provide new insights into fundamental mechanisms of the host defense against viral pathogens, and may ultimately lead to the development of safe and effective Ad vectors for the therapy of a wide range of inborn and acquired human diseases.