Dextran Sulfate, Beta Cell Preservation and Immune Regulation in Type 1 Diabetes

硫酸葡聚糖、β 细胞保存和 1 型糖尿病的免疫调节

• 批准号: 9289335
• 负责人: Adolfo Garcia-Ocana
• 金额: $ 42.38万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2021-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9289335
• 关键词: Address; Antigen-Presenting Cells; Antigens; Autoimmunity; B-Lymphocytes; Bacterial Polysaccharides; Basement membrane; Beta Cell; Biological Preservation; CD8-Positive T-Lymphocytes; Cell Death; Cell Survival; Cell physiology; Cells; Complement; Dendritic Cells; Development; Dextran Sulfate; Dextrans; Diabetes Mellitus; Disease; Early treatment; Effector Cell; Endothelium; Environment; Extracellular Matrix; HGF gene; Human; Immune; Immune Tolerance; Immune system; Impairment; In Vitro; Inbred NOD Mice; Incidence; Individual; Infiltration; Inflammation; Inflammatory; Insulin-Dependent Diabetes Mellitus; Knowledge; Lead; Lectin; Ligands; Lymphocyte Activation; Maintenance; Mediating; Molecular; Molecular Weight; Mus; Natural regeneration; PDCD1LG1 gene; Phenotype; Polysaccharides; Prevalence; Prevention; Preventive; Production; Public Health; Reporting; Self Tolerance; Signal Transduction; Splenocyte; Stimulus; Stress; Structure of beta Cell of islet; T cell response; T-Lymphocyte; Testing; Therapeutic; Therapeutic Effect; Tissues; Treatment Factor; Treatment Protocols; Unspecified or Sulfate Ion Sulfates; Up-Regulation; autoreactive T cell; cytokine; cytotoxic; diabetic; early onset; efficacy testing; immunoregulation; islet; macrophage; member; mouse model; peripheral tolerance; prevent

Type 1 diabetes (T1D), with a prevalence of ~200/100,000 and an incidence that has been increasing by 2-5% worldwide over the past few years, poses a considerable challenge to afflicted individuals, to the development of effective prevention and treatment regimens, and to public health initiatives at large. Therapies focused on preserving functional beta cells; gaining immune tolerance; and inducing beta cell regeneration are a priority for the treatment of the disease. The sulfated polysaccharide Dextran Sulfate (DS) is a polyanionic derivative of the bacterial polysaccharide dextran. Preliminary studies from our lab suggest that low molecular weight DS (5-8kDa) is a prosurvival agent for the beta cell in vitro against cytokines and ER stress. However, the molecular mechanisms involved in these effects are unknown. In addition, whether DS protects beta cell function in a proinflammatory environment is also unknown. Upregulation of the inhibitory co-stimulatory signal PD-1/PD-L1 provides negative stimuli influencing T lymphocyte activation and promoting the maintenance of peripheral tolerance. Preliminary studies indicate that DS treatment of splenocytes in vitro leads to a significant increase in the number of DCs, B cells and macrophages expressing PD-L1. DS also increases the number of activated CD4+ and CD8+ T cells expressing PD-1. This suggests that DS could help to maintain peripheral tolerance in a setting predisposed to autoimmunity. To test the efficacy of DS for T1D treatment, we have analyzed the effect of DS in the prevention and reversal of diabetes in the NOD mouse, the spontaneous mouse model of T1D. DS treatment impairs beta cell death, preserves beta cell mass and prevents the development of T1D in pre-diabetic NOD mice. More importantly, DS treatment of early onset diabetic NOD mice reverses diabetes in ~70% of the mice. DS treatment preserves beta cell mass with intact islets surrounded by massive number of immune cells, suggesting islet infiltration impairment, decreased cytokine production and/or enhanced beta cell survival. Interestingly, treatment of NOD mice with a blocking mAb against PD-L1 completely abrogated the preventive effects of DS in diabetes development. Collectively, these studies suggest a promising therapeutic effect of DS for T1D by potentially preserving functional beta cells, gaining immune tolerance and enhancing beta cell regeneration. Our hypothesis is that DS reverses T1D by favoring the survival and maintaining the function of the beta cell in an islet inflammation environment, and by modulating the immune system to enhance tolerance. To determine whether our hypothesis is correct, we will develop the following Specific Aims: Specific Aim 1. To determine the effect and molecular mechanisms mediated by DS on beta cell survival and function in the context of T1D. Specific Aim 2. To analyze the efficacy of dextran sulfate (DS) treatment alone or in combination with hepatocyte growth factor (HGF) for reversing diabetes in NOD mice. Specific Aim 3. To dissect and stratify DS-induced immunomodulatory effects on human T cell responses. The proposed studies will provide significant information regarding the therapeutic potential of DS for T1D and the cellular and molecular mechanisms involved in the beneficial effects of this sulfated polysaccharide.

1型糖尿病（T1 D），患病率约为200/100，000，发病率一直在增加2-5% 在过去几年中，世界范围内的疟疾对受影响的个人、有效预防和治疗方案的发展以及整个公共卫生倡议构成了相当大的挑战。专注于保护功能性β细胞的治疗;获得免疫耐受;和诱导β细胞再生是治疗该疾病的优先事项。硫酸化多糖硫酸葡聚糖（DS）是细菌多糖葡聚糖的聚阴离子衍生物。我们实验室的初步研究表明，低分子量DS（5- 8 kDa）是体外β细胞对抗细胞因子和ER应激的促存活剂。然而，这些影响所涉及的分子机制是未知的。此外，DS是否在促炎环境中保护β细胞功能也是未知的。抑制性共刺激信号PD-1/PD-L1的上调提供了影响T淋巴细胞活化和促进外周耐受维持的负性刺激。初步研究表明，体外脾细胞的DS处理导致表达PD-L1的DC、B细胞和巨噬细胞数量显著增加。DS还增加表达PD-1的活化的CD 4+和CD 8 + T细胞的数量。这表明，DS可以帮助维持外周耐受性的设置倾向于自身免疫。为了检测DS治疗T1 D的疗效，我们分析了DS在NOD小鼠（T1 D的自发小鼠模型）中预防和逆转糖尿病的作用。DS治疗可减少糖尿病前期NOD小鼠的β细胞死亡，保留β细胞群并预防T1 D的发展。更重要的是，DS治疗早发性糖尿病NOD小鼠可逆转约70%小鼠的糖尿病。DS治疗保留了β细胞群，完整胰岛被大量免疫细胞包围，表明胰岛浸润受损，细胞因子产生减少和/或β细胞存活增加。有趣的是，用PD-L1阻断mAb治疗NOD小鼠完全消除了DS在糖尿病发展中的预防作用。总的来说，这些研究表明DS通过潜在地保留功能性β细胞、获得免疫耐受性和增强β细胞再生而对T1 D具有有希望的治疗作用。我们的假设是，DS通过促进胰岛炎症环境中β细胞的存活和维持其功能， 调节免疫系统以增强耐受性。为了确定我们的假设是否正确，我们将制定以下具体目标：具体目标1。确定DS对T1 D背景下β细胞存活和功能介导的作用和分子机制。具体目标2。分析硫酸葡聚糖（DS）单独或与肝细胞生长因子（HGF）联合治疗逆转NOD小鼠糖尿病的疗效。 具体目标3。解剖和分层DS诱导的免疫调节作用对人类T细胞的反应。拟定的研究将提供关于DS治疗T1 D的潜力的重要信息， 这种硫酸化多糖的有益作用所涉及的细胞和分子机制。