Mechanisms of Fas Ligand Control of Insulitis in Autoimmune Diabetes

Fas配体控制自身免疫性糖尿病胰岛素炎的机制

• 批准号: 8504356
• 负责人: Abdel Rahim Hamad
• 金额: $ 34.5万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-03-01 至 2018-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8504356
• 关键词: Animal Model; Anti-Inflammatory Agents; Anti-inflammatory; Apoptosis; Autoantigens; Autoimmune Diabetes; Autoimmune Process; B-Lymphocyte Subsets; B-Lymphocytes; Biological Models; Cell Death; Cells; Data; Defect; Diabetes Mellitus; Disease; Disease susceptibility; Equilibrium; Failure; Family; Frequencies; Genetic; Goals; Homeostasis; Hyperglycemia; Immune; Immune response; Immunocompetent; Immunosuppressive Agents; Immunotherapy; Inbred NOD Mice; Individual; Injection of therapeutic agent; Insulin; Insulin-Dependent Diabetes Mellitus; Interleukin-10; Investigation; Islets of Langerhans; Knowledge; Lead; Mediating; Modality; Modeling; Mus; Newly Diagnosed; Non obese; Pancreas; Pathogenesis; Pathway interactions; Patients; Predisposition; Process; Production; Role; Sampling; Signal Transduction; Site; System; T-Lymphocyte; Testing; Therapeutic; Tissues; Treatment Efficacy; Tumor Necrosis Factor Ligand Superfamily Member 6; Tumor Necrosis Factor-alpha; autoreactive T cell; base; blood glucose regulation; cell type; clinically significant; cytokine; design; diabetic; human disease; insight; islet; lymph nodes; member; mouse model; neutralizing monoclonal antibodies; novel therapeutic intervention; pre-clinical; prevent; public health relevance

DESCRIPTION (provided by applicant): Despite improvement in insulin delivery, maintaining tight control of glucose homeostasis continues to be a challenge that results in bouts of severe hypo and hyperglycemia and serious long-term complications in many type 1 diabetes (T1D) patients. Therefore, developing an immunotherapy for the disease remains a major goal. Reaching this goal, however, requires deep knowledge of all facets of the diabetogenic process - which is generally believed to be initiated by an imbalance between pathogenic and regulatory mechanisms that allows diabetogenic T cells to infiltrate pancreatic islets and destroy insulin-producing ss-cells. Therefore, identifying and understanding roles of various molecules and cell types that tip the balance towards the immunopathogenic pathways in susceptible individuals and animal models is important for developing effective immunotherapy. This proposal investigates mechanisms that powerfully control ss-cell specific autoreactive T cells when Fas ligand (FasL), an apoptosis-inducing member of TNF family, is genetically or pharmacologically inactivated. Previously, the lack of appropriate models and efficacious FasL blocking mAb has severely hampered such investigation. In this application, we will use NOD mice that are haploinsufficient for FasL (NOD-gld/+ mouse) and a FasL- neutralizing mAb (MFL4 clone) to investigate the underlying mechanisms and therapeutic significance of FasL blockade using the MFL4 mAb. NOD-gld/+ mice are completely protected from T1D, immunocompetent, and have normal immune homeostasis. In addition, MFL4 mAb protects NOD-wt mice from diabetes without altering immune homeostasis and, more importantly, our preliminary data show it has promising efficacy in reversing hyperglycemia in new-onset cases. Based on our preliminary data generated using these model systems, we hypothesize that an IL-10-producing regulatory B cell subset that suppresses diabetogenic autoreactive T cells are negatively regulated by FasL. In NOD-wt mice, FasL-mediated apoptosis eliminates IL- 10-producing regulatory B cells thereby removing the brakes on autoreactive T-cells (tested Aim 1). We hypothesize that the MFL4 mAb can be used to reverse new-onset diabetes (tested in Aim 2). In NOD mice, haploinsufficiency for FasL (gld/+) or mAb blockade of FasL prevents IL-10-producing B cell elimination, leading to control of diabetogenic T cells and suppression of insulitis (tested in Aim 3). In this revised application, we will also assess relevance of our preclinical data to the human disease in samples from newly diagnosed patients at Hopkins and tissues provided by the JDRF sponsored nPOD project (Aim 3). Because the role of FasL in normal immune response and ss-cell death are dispensable, understanding how FasL modulates the diabetogenic process can lead to new mechanistic insights into the disease pathogenesis that could have important therapeutic implications.

描述（由申请方提供）：尽管胰岛素输送得到改善，但维持葡萄糖稳态的严格控制仍然是一项挑战，导致许多1型糖尿病（T1 D）患者出现严重低血糖和高血糖发作以及严重的长期并发症。因此，开发针对该疾病的免疫疗法仍然是一个主要目标。然而，达到这一目标需要深入了解糖尿病发生过程的各个方面-通常认为这是由致病机制和调节机制之间的不平衡引发的，该机制允许糖尿病发生T细胞浸润胰岛并破坏产生胰岛素的ss细胞。因此，识别和理解各种分子和细胞类型的作用，这些分子和细胞类型使易感个体和动物模型中的免疫致病途径平衡，对于开发有效的免疫疗法非常重要。本研究旨在探讨当TNF家族中的Fas配体（FasL）基因失活或失活时，对β细胞特异性自身反应性T细胞的有效调控机制。以前，缺乏合适的模型和有效的FasL阻断mAb严重阻碍了这种研究。在本申请中，我们将使用FasL单倍不足的NOD小鼠（NOD-gld/+小鼠）和FasL中和mAb（MFL 4克隆）来研究使用MFL 4 mAb阻断FasL的潜在机制和治疗意义。NOD-gld/+小鼠完全免受T1 D的影响，具有免疫活性，并具有正常的免疫稳态。此外，MFL 4 mAb保护NOD-wt小鼠免受糖尿病的影响，而不改变免疫稳态，更重要的是，我们的初步数据显示，它在逆转新发病例中的高血糖症方面具有很好的疗效。基于我们使用这些模型系统产生的初步数据，我们假设抑制致糖尿病自身反应性T细胞的产生IL-10的调节性B细胞亚群受FasL负调控。在NOD-wt小鼠中，FasL介导的细胞凋亡消除了产生IL- 10的调节性B细胞，从而消除了对自身反应性T细胞的制动（测试目的1）。我们假设MFL 4 mAb可用于逆转新发糖尿病（在目标2中测试）。在NOD小鼠中，FasL的单倍不足（gld/+）或FasL的mAb阻断阻止产生IL-10的B细胞消除，导致致糖尿病性T细胞的控制和胰岛炎的抑制（在Aim中测试）。 3）。在这份修订后的申请中，我们还将评估我们的临床前数据与人类的相关性。 来自霍普金斯新诊断患者的样品和由JDRF赞助的nPOD项目提供的组织中的疾病（Aim 3）。由于FasL在正常免疫应答和ss细胞死亡中的作用是不确定的，因此了解FasL如何调节糖尿病发生过程可以导致对疾病发病机制的新的机制见解，这可能具有重要的治疗意义。