Determining the rap1b signaling pathway to integrin activation in platelets

描述（由申请人提供）：1型糖尿病（T1DM）是由自身免疫破坏胰腺细胞引起的，并导致终生依赖每日胰岛素注射。流行病学数据显示，1型糖尿病发病率每年上升2-3%，发病年龄较早。由于从糖尿病前期儿童获得相关免疫组织几乎是不可能的，我们使用了BioBreeding （BB）大鼠的同源衍生物。淋巴细胞减少的DRIyp/lyp动物发生自发性T1DM，而DR+/+动物则不会。有证据表明，BB大鼠的疾病进展依赖于天然调节性T （nTreg）细胞的缺失。BB大鼠的T1DM也涉及细胞毒性T细胞，因为它们的消耗具有保护作用。我们的初步研究表明，BB大鼠易患T1型糖尿病，因为DRIyp/lyp和DR+/+菌株的胰腺细胞在DRIyp/lyp大鼠发生胰岛素之前，通过表达eotaxin（一种嗜酸性粒细胞和肥大细胞募集趋化因子）和白细胞介素1 （interleukin 1）募集免疫细胞。糖尿病前期胰腺淋巴结（PLN）的基因表达研究表明，相比于糖尿病前期，DRIyp/lyp动物的肥大细胞被最终激活。在DR+/+动物中呈负调控。我们用两种不同的肥大细胞抑制药物成功延缓了DRIyp/lyp大鼠的T1DM，证实了肥大细胞的致病作用。因此，我们认为DR+/+大鼠的nTreg细胞可以通过外周调节机制维持胰岛健康，而在缺乏nTreg细胞的情况下，DRIyp/lyp动物会自发发展为T1DM。我们假设在BB大鼠中，先天免疫细胞介导胰岛破坏，除非nTreg细胞阻止它们的动员。我们将通过以下目标来验证我们的假设：1)使用功能基因组学和组织学方法的结合，在时间和空间上解剖糖尿病前期第30天（胰岛eotaxin信号传导之前）、第40天（胰岛素之前）、第50天（早期胰岛素）和第60天（晚期胰岛素，发病前）的nTreg细胞的活性。2)通过体外和体内研究验证Aim 1的观察结果，表征nTreg对CD8和CD4 T细胞以及先天细胞的作用。肥大细胞在T1DM中启动和/或放大自身免疫中的作用直到最近才被定义。这些研究将利用基因组学、生物信息学、组织学和免疫学方法来阐明先天细胞和nTreg细胞之间的关系。这种综合方法将帮助我们更好地了解肥大细胞和nTreg细胞如何相互作用，并有可能建立免疫调节的新范式，从而为免疫疾病开辟新的见解。

DESCRIPTION (provided by applicant): Type 1 diabetes mellitus (T1DM) arises through autoimmune destruction of pancreatic ¿ cells and results in life-long dependency on daily insulin injection. Epidemiological data show that T1DM incidence is rising by 2-3% per year while onset is occurring at an earlier age. Since acquisition of relevant immune tissues from prediabetic children is nearly impossible, we have used congenic derivatives of the BioBreeding (BB) rat. The lymphopenic DRIyp/lyp animal develops spontaneous T1DM, whereas the DR+/+ does not. Evidence points to disease progression in BB rats being dependent on the absence of natural regulatory T (nTreg) cells. T1DM in BB rats also involves cytotoxic T cells, since their depletion is protective. Our preliminary studies show that BB rats are predisposed to T1 DM in that pancreatic ¿ cells of both DRIyp/lyp and DR+/+ strains recruit immune cells through expression of eotaxin, an eosinophil and mast cell recruiting chemokine, as well as interleukin 1¿ prior to insulitis in the DRIyp/lyp rat. Gene expression studies of prediabetic pancreatic lymph nodes (PLN) have shown that mast cells are terminally activated in DRIyp/lyp animals versus.negatively regulated in DR+/+ animals. We have successfully delayed T1DM in DRIyp/lyp rats with two different mast cell inhibiting drugs, confirming a pathogenic role for mast cells. Thus, we propose that nTreg cells in the DR+/+ rat can maintain the islet health by a peripheral regulatory mechanism, whereas in the absence of nTreg cells, DRIyp/lyp animals spontaneously progress to T1DM. We hypothesize that in the BB rat, innate immune cells mediate islet destruction unless nTreg cells prevent their mobilization. We will test our hypotheses through the following aims: 1) Temporally and spatially dissect the activities of nTreg cells during the prediabetic period at day 30 (prior to islet eotaxin signaling), day 40 (prior to insulitis), day 50 (early insulitis) and day 60 (late insulitis, pre-onset) using a combination of functional genomics and histological approaches. 2) Validate Aim 1 observations through in vitro and in vivo studies that characterize the action of nTreg on CD8 and CD4 T cells as well as innate cells. A role for mast cells in initiating and/or amplifying autoimmunity in T1DM has only recently been defined. These studies will utilize genomic, bioinformatic, histological, and immunological approaches to elucidate the relationship between innate cells and nTreg cells. This integrated approach will help us better understand how mast cells and nTreg cells interact and has the potential to establish a new paradigm for immune regulation, thus opening new insights into immune disease.