Cellular and Genetic Mechanisms of Autoimmune Diabetes Associated Neuritis

项目摘要 1型糖尿病（T1 D）通常伴有其他自身免疫性疾病，包括自身免疫性 神经病在NOD小鼠和患者中的发现揭示了免疫系统之间的潜在重叠。 靶向胰腺B细胞和神经的反应。我们假设，淋巴细胞群参与 靶向神经系统中共表达的T1 D发病机制蛋白可能是最早的应答者 造成周围神经的初步损伤。这些第一反应者提供了必要的触发器， 针对髓磷脂和其他神经系统成分的免疫反应，传统上在现有的 自身免疫性神经炎的小鼠模型。NOD小鼠中绝大多数的胰岛浸润B淋巴细胞 神经系统蛋白外周蛋白。针对磷酸化外周蛋白的抗体已经在 T1 D患者我们最近建立了一种新的小鼠模型（NOD-PerIg），其中B淋巴细胞转基因 表达从胰岛分离的外周蛋白反应性B细胞克隆H280的免疫球蛋白分子。T1d 在NOD-PerIg小鼠中加速。来自NOD-PerIg而非NOD小鼠的T细胞转移自身免疫性神经炎 类似于NOD.scid受体的慢性脱髓鞘性多发性神经病（CIDP）。这个新的NOD-PerIg à T1 D相关自身免疫性神经炎的NOD.scid模型提供了直接解剖 神经细胞浸润和损伤的各个阶段我们最初假设胰岛炎扩大了T- 能够引起神经炎的细胞。然而，我们最近已经确定，来自胰岛或 原发性NOD.scid受体的坐骨神经仅能够浸润它们所来自的器官 推导因此，目标1中的实验将解决关于离散时间的当前未知数。 以及导致细胞募集到外周神经中的空间步骤。我们还发现，除了 产生IFNg和TNF α的CD 4 + T细胞的存在，矛盾的是T细胞的扩增 坐骨神经内传统Th 1、Th 2和Th 17细胞因子阴性。另一个未决问题是 外周蛋白是否仍然是T细胞应答的抗原，或者是否存在免疫应答。 对其他神经元抗原的反应扩大。因此，目标2中的研究将剖析 T细胞破坏外周神经的机制，以及针对一个共享B- 细胞/神经元抗原可以溢出到更广泛的神经元反应。最后，在大型NOD菌落中， 偶尔可以观察到临床神经炎。我们发现，在基线时，NOD小鼠（年龄约为 T1 D发作）已经有坐骨神经浸润T细胞。这些T细胞在非自身免疫性 易感C57 BL/6小鼠。这表明NOD可能含有导致自发性高血压的遗传位点。 神经浸润会导致自发性神经炎这些基因座是否与基因座不同或重叠 导致T1 D的原因尚不清楚。因此，目标3中的研究将绘制与自发性 神经浸润允许将来对有发展自身免疫性神经病风险的患者进行遗传筛查。

PROJECT SUMMARY Type 1 diabetes (T1D) is often accompanied by other autoimmune disorders, including autoimmune neuropathies. Findings in both NOD mice and patients have revealed potential overlap between immune responses targeting pancreatic b-cells and nerves. We hypothesized that lymphocyte populations involved in T1D pathogenesis targeting proteins co-expressed in the nervous system may be the earliest responders causing initial damage to peripheral nerves. These first responders provide the necessary trigger to expand immune responses against myelin and other nervous system components traditionally studied in existing mouse models of autoimmune neuritis. A vast majority of islet-infiltrating B-lymphocytes in NOD mice respond to the nervous-system protein peripherin. Antibodies against phosphorylated peripherin have been identified in T1D patients. We recently created a new mouse model (NOD-PerIg) in which B-lymphocytes transgenically express the immunoglobulin molecule from the peripherin-reactive B-cell clone H280 isolated from islets. T1D is accelerated in NOD-PerIg mice. T-cells from NOD-PerIg, but not NOD mice, transfer an autoimmune neuritis similar to chronic demyelinating polyneuropathy (CIDP) to NOD.scid recipients. This new NOD-PerIg à NOD.scid model of T1D-associated autoimmune neuritis provides an experimental system to directly dissect the discreet stages of nerve cell infiltration and damage. We originally hypothesized that insulitis expanded T- cells capable of causing neuritis. However, we have recently determined that T-cells derived from islets or sciatic nerves in primary NOD.scid recipients are only capable of infiltrating the organ from which they were derived. Therefore, experiments in Aim 1 will address the current unknowns regarding the discrete temporal and spatial steps leading to cellular recruitment into peripheral nerves. We have also found that in addition to the presence of IFNg and TNFa producing CD4+ T-cells, there is paradoxically an expansion of T-cells negative for traditional Th1, Th2, and Th17 cytokines within sciatic nerves. An additional open question is whether peripherin remains the antigen towards which T-cells are responding or whether there has been an expansion of responses against other neuronal antigens. Therefore, studies in Aim 2 will dissect the mechanisms by which T-cells destroy peripheral nerves and how an immune response against one shared b- cell/neuronal antigen can spill over to a wider neuronal response. Finally, in large NOD colonies, spontaneous clinical neuritis can be occasionally observed. We have found that at baseline, NOD mice (around the age of T1D onset) already have sciatic nerve infiltrating T-cells. These T-cells are not observed in non-autoimmune prone C57BL/6 mice. This indicates the likelihood that NOD harbors genetic loci contributing to spontaneous nerve infiltration that can lead to spontaneous neuritis. Whether these loci are distinct or overlapping with loci contributing to T1D is unknown. Therefore, studies in Aim 3 will map genes associated with spontaneous nerve infiltration allowing future genetic screening of patients at risk for developing autoimmune neuropathy.