MECHANISMS OF VIRAL INDUCED BETA CELL DAMAGE

描述(摘自申请者摘要)：胰岛素依赖型糖尿病 糖尿病(IDDM)是一种自身免疫性疾病，以选择性 胰岛中发现的产生胰岛素的β细胞的破坏 朗格汉斯。环境因素，如病毒感染，被认为 触发或启动这种针对β细胞的自身免疫反应。 对病毒诱导的糖尿病动物模型的研究表明， 巨噬细胞和巨噬细胞衍生细胞因子在介导β细胞中的作用 在糖尿病发展过程中的损害。这项研究的总体目标是 是为了确定病毒感染的生化机制 胰岛介导了β细胞功能障碍和破坏。双链RNA (DsRNA)是病毒感染的活性成分，它刺激 抗病毒反应。在初步数据中，dsRNA，in 与T细胞细胞因子干扰素-γ(干扰素-γ)相结合， 刺激巨噬细胞活化，诱导胰岛功能障碍 毁灭。这项建议的重点是确定生化指标 双链RNA刺激巨噬细胞活化和诱导的机制 β细胞损伤。有两个具体目标。 特定目标1将阐明细胞信号机制，通过它 DsRNA刺激巨噬细胞激活。拟议的实验将集中在 DsRNA依赖的蛋白激酶(PKR)在介导dsRNA诱导的： (1)诱导型一氧化氮合酶(INOS)表达与一氧化氮 产生；(2)原代巨噬细胞表达和释放细胞因子。 目标2将测试假设，病毒感染的胰岛刺激 诱导白细胞介素1的表达和释放对β细胞的损伤 (IL-1)通过β细胞(正如我们的初步数据所表明的)。建议 实验将确定(1)dsRNA刺激IL-1的机制 以及(2)PKR在dsRNA诱导中的作用 β细胞的破坏。 一些生化、分子生物学、免疫学、组织化学、 转基因技术将被用来研究细胞 病毒感染刺激巨噬细胞激活和释放的途径 会导致小岛的毁灭。人们希望对分子的洞察 病毒介导的β细胞损伤的机制 研究将影响新的治疗策略的设计，目的是 预防这种令人衰弱的疾病。

DESCRIPTION (adapted from applicant's abstract): Insulin-dependent diabetes mellitus (IDDM) is an autoimmune disease characterized by the selective destruction of insulin producing beta-cells found in pancreatic islets of Langerhans. Environmental factors, such as viral infections, are believed to trigger or initiate this autoimmune reaction directed against beta cells. Studies in animal models of viral-induced diabetes have implicated a primary role for macrophages and macrophage-derived cytokines in mediating beta-cell damage during the development of diabetes. The broad goal of this research is to determine the biochemical mechanisms by which viral infection of islets mediates beta-cell dysfunction and destruction. Double stranded RNA (dsRNA) is the active component of a viral infection that stimulates antiviral responses. In preliminary data, it is shown that dsRNA, in combination with the T-cell cytokine interferon-gamma (IFN-gamma), stimulates the activation of macrophages and induces islet dysfunction and destruction. This proposal focuses on determining the biochemical mechanisms by which dsRNA stimulates macrophage activation and induces beta-cell damage. There are two specific aims. Specific aim 1 will elucidate the cellular signaling mechanisms by which dsRNA stimulates macrophage activation. Proposed experiments will focus on the role of dsRNA-dependent protein kinase (PKR) in mediating dsRNA-induced: (1) inducible nitric oxide synthase (iNOS) expression and nitric oxide production; and (2) cytokine expression and release by primary macrophages. Aim 2 will test the hypothesis that viral infection of islets stimulates beta-cell damage by inducing the expression and release of interleukin-1 (IL-1) by beta cells (as suggested by our preliminary data). Proposed experiments will determine (1) the mechanism by which dsRNA stimulates IL-1 and iNOS expression by beta cells; and (2) the role of PKR in dsRNA-induced beta-cell destruction. A number of biochemical, molecular biological, immunological, histochemical, and transgenic techniques will be utilized to investigate the cellular pathways through which viral infection stimulates macrophage activation and induces islet destruction. It is hoped that insights into the molecular mechanisms of viral-mediated beta-cell damage gained from the proposed studies will influence the design of novel therapeutic strategies aimed at the prevention of this debilitating disorder.