Regulation of IDDM by Proinflammatory and Th1-cytokines

描述(申请人提供)：胰岛素依赖型糖尿病(IDDM)的特征是T淋巴细胞渗透到胰腺朗格汉斯的胰岛(胰岛素炎)，继而选择性地破坏分泌胰岛素的β细胞，导致明显的糖尿病。我们初步观察到IDDM与AIM因子(一种我们最初确定为凋亡抑制因子的分泌分子)之间的重要关联是：(1)AIM[-/-]小鼠回交到非肥胖糖尿病(NOD)背景显示完全预防IDDM；(2)AIM从疾病的早期就通过渗透到胰岛的巨噬细胞表达；(3)AIM强烈诱导巨噬细胞和树突状细胞(DC)中的TNF-α、IL-1β、IL-6和IL-12。在此基础上，提出了一种假说：在IDDM发病初期，AIM可能通过诱导炎性细胞因子和I型细胞因子在胰岛中最初渗入的巨噬细胞和DC中加速IDDM的发生。具体目标1和2集中于通过重新添加AIM缺失NOD小鼠巨噬细胞中AIM的表达来建立假设的合理性(Aim 1)，并通过评估Tet诱导转基因系统诱导巨噬细胞和DC中的细胞因子是否可以克服AIM缺失NOD小鼠的疾病预防(Aim 2)来测试AIM信号下游的细胞因子对疾病加速的影响。此外，我们最近的研究结果表明，AIM可能是Toli/IL-1受体家族中的一员。在具体目标3中，我们将通过从巨噬细胞中获得的cDNA文库的表达筛选来纯化和鉴定AIM受体。我们还计划通过破坏NOD来源的ES细胞中的基因来创建AIM受体的敲除小鼠，因为我们使用这些细胞产生了AIM[-/-]/-NOD。我们提出的研究将阐明IDDM在AIM背景下的确切发病机制，特别是在疾病的早期阶段，因此将有助于通过抑制AIM来开发新的治疗方法。此外，AIM受体的鉴定将有助于阐明AIM功能的精确分子机制，以及Toll家族生理功能的新方面。

DESCRIPTION (provided by applicant): Insulin-dependent diabetes mellitus (IDDM) is characterized by the infiltration of T-lymphocytes into the islets of Langerhans of the pancreas (insulitis), followed by selective destruction of insulin-secreting beta cells leading to overt diabetes. Preliminarily, we observed the important association of IDDM with AIM factor (a secretion molecule we initially identified as an apoptosis inhibitory factor), which are: (1) AIM [-/-] mice backcrossed to non-obese diabetes (NOD) background showed complete prevention of IDDM; (2) AIM is expressed by infiltrating macrophages in the pancreatic islets from the very early stage of the disease; (3) AIM strongly induces TNF-alpha, IL-1 beta, IL-6 and IL-12 in macrophages and dendritic cells (DCs). Based on these, a hypothesis has emerged that AIM may accelerate IDDM by inducing pro-inflammatory- and type I- cytokines in initially infiltrating macrophages and DCs in the islets at the onset stage of the disease. The Specific Aim 1 and 2 are focused on establishing the propriety of the hypothesis by adding back the AIM expression in macrophages in AIM-null NOD mice expecting the disease recurrence (aim 1), and testing the impact of the cytokines downstream of AIM signaling on the disease acceleration by assessing whether the induction of the cytokines in macrophages and DCs via the Tet-inducible transgenic system may overcome the disease prevention in AIM-null NOD mice (aim 2). In addition, our recent result that AIM mediates Toll-signaling to induce the cytokines provoked an idea that the putative AIM-receptor may be a TolI/IL-1 receptor family member. In the Specific Aim 3, we will purify and characterize the AIM-receptor by expression screening of a cDNA library generated from macrophage cells. We also plan to create knockout mice of the AIM-receptor by disrupting the gene in the NOD-derived ES cells, as we generated AIM[-/-]/-NOD by using the cells. Our proposed studies will clarify the precise picture of the IDDM pathogenesis in the context of AIM, in particular, during the early stage of the disease, and thus will contribute to development of a new therapy via suppression of AIM. In addition, identification of AIM-receptor will shed light on the precise molecular machinery of AIM functions, as well as a new aspect of physiological function of the Toll-family.