Genetic Regulation of Human Beta Cell Destruction

人类β细胞破坏的基因调控

• 批准号: 8813679
• 负责人: CLAYTON E MATHEWS
• 金额: $ 311.66万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-30 至 2019-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8813679
• 关键词: Affect; Alleles; Antigens; Autoimmune Process; Autoimmunity; Beta Cell; Biology; Blood Vessels; CD8-Positive T-Lymphocytes; CD8B1 gene; Cell Death; Cells; Cessation of life; Complex; Coupled; Cytolysis; Data; Defect; Dendritic Cells; Dendritic cell activation; Development; Discipline; Disease; Disease Progression; Disease Resistance; Elements; Endogenous Factors; Endothelial Cells; Environment; Event; Exogenous Factors; Figs - dietary; Future; Genes; Genetic; Genetic Risk; Goals; Grant; Homing; Human; Immune; Immune Tolerance; Immune system; Immunogenetics; Immunology; Individual; Inflammation; Insulin; Insulin-Dependent Diabetes Mellitus; Investigation; Knowledge; Link; Lymphocyte Activation; Lymphocyte Function; Lymphoid; Mediating; Modeling; Molecular; Mus; PTPN22 gene; Pancreas; Pathogenesis; Play; Polygenic Traits; Population; Predisposition; Process; Regulation; Relative (related person); Research Design; Resistance; Risk; Role; Solutions; Stem cells; Susceptibility Gene; System; T-Lymphocyte; Technology; Testing; Variant; base; cell type; cellular engineering; cytotoxic; diabetes mellitus genetics; genetic element; genetic risk factor; human PTPN22 protein; immunogenic; improved; induced pluripotent stem cell; innovation; insulin dependent diabetes mellitus onset; islet; novel; public health relevance; response; risk variant; stem cell technology; uptake; vascular inflammation

 DESCRIPTION (provided by applicant): The development of Type 1 Diabetes (T1D) relies on complex interrelationships between cells of the immune system [e.g., DC, CD8+ T cells] and genes imparting susceptibility or resistance to the disease that underlie the autoimmune destruction of insulin producing pancreatic β cells. While a broad body of evidence certainly exists to support this notion (and we ourselves believe it true), the exact mechanism by which autoimmune β cell destruction is facilitated remains unclear. In addition, the relative contributions of each facet (i.e., cells, genes) play in the process remain, to a large extent, unknown. Mechanistic studies of T1D-associated susceptibility alleles are complicated by polygenic inheritance such that no two individuals are truly alike. Hence, studies are severely hampered by a lack of power in populations, and the inability to isolate the functional impact of a variant to a specific cell type. Here we present a solution that focuses on individual alleles usin an innovative isogenic mode that takes advantage of cutting edge technologies. We have created an experimental platform to study how specific genetic risk variants precipitate immune dysregulation leading to cytotoxic CD8+ T lymphocyte (CTL) activation and β cell destruction. We hypothesize that genetically regulated defects in PTPN22 promote; i) immunogenic DC, ii) TH1 responses, iii) pancreatic vascular inflammation and CTL homing, and iv) pathogenic CTL activity towards β cells coupled with reduced activation induced CTL death: each of these tenants form an aim of this grant. Further, we posit that defects reach full potential when immune cells and endothelial cells are excessively sensitive to activation by endogenous or exogenous factors that stimulate inflammation, thus linking environment and immunogenetics in T1D. Here we will utilize a novel experimental pipeline where PTPN22R (T1D resistant), PTPN22W (T1D susceptible) or PTPN22 deletion (PTPN22-/-) alleles are carried by isogenic human immune and endothelial cells engineered from induced pluripotent stem cells [iPSC]. The iPSC system allows exquisite control of T1D disease alleles, where the susceptible allele can be replaced by the resistant allele (and vice versa) providing a constant genetic background upon which effects of a single risk allotype can be studied without complicating epistatic effects, in a manner analogous to studies in genetically modified mice. This system proposed here will provide an unprecedented capacity to interrogate molecular and cellular interactions under isogenic conditions to provide mechanistic understanding of how PTPN22 alleles regulate individual steps of T1D pathogenesis and how those steps interrelate to bring upon T1D onset. Importantly, this study will also lay the groundwork for future investigations of single or multipl T1D susceptibility genes using this innovative strategy.

 描述(申请人提供)：1型糖尿病(T1D)的发展依赖于免疫系统细胞(例如，DC、CD8+T细胞)和赋予疾病易感性或抵抗力的基因之间的复杂相互关系，这些基因是产生胰岛素的胰腺β细胞的自身免疫破坏的基础。虽然大量的证据肯定支持这一观点(我们自己也相信这是真的)，但促进自身免疫β细胞破坏的确切机制仍不清楚。此外，在这一过程中，每个方面(即细胞、基因)的相对贡献在很大程度上仍然是未知的。T1D相关易感等位基因的机制研究因多基因遗传而变得复杂，因此没有两个个体是真正相似的。因此，研究严重受阻于人群中缺乏动力，以及无法分离出 一种特定细胞类型的变体。在这里，我们提出了一种专注于单个等位基因的解决方案，使用了一种利用尖端技术的创新等基因模式。我们已经建立了一个实验平台来研究特定的遗传风险变异如何导致免疫失调，导致细胞毒性CD8+T淋巴细胞激活和β细胞破坏。我们假设，PTPN22的基因缺陷促进了：i)免疫原性DC，ii)TH1反应，iii)胰腺血管炎症和CTL归巢，以及iv)致病的CTL活性与β细胞的激活减少导致的CTL死亡：每个租户都形成了这项赠款的目标。此外，我们假设，当免疫细胞和内皮细胞对刺激炎症的内源性或外源性因素激活过度敏感时，缺陷达到完全潜力，从而将环境和免疫遗传学联系在一起。在这里，我们将利用一种新的实验管道，其中PTPN22R(T1D抗性)、PTPN22W(T1D易感)或PTPN22缺失(PTPN22-/-)等位基因由同源的人免疫和诱导多能干细胞工程内皮细胞[IPSC]携带。IPSC系统允许精确控制T1D疾病等位基因，其中敏感等位基因可以被抗性等位基因取代(反之亦然)，提供了一个恒定的遗传背景，在该背景下可以研究单一风险同种异型的影响，而不会使上位效应复杂化。 以一种类似于对转基因小鼠的研究的方式。该系统将提供前所未有的能力，以询问分子和细胞在等基因条件下的相互作用，以提供机制的理解如何PTPN22等位基因调节的T1D发病的个别步骤，以及这些步骤如何相互关联，导致T1D的发病。重要的是，这项研究还将为未来使用这一创新策略研究单个或多个T1D易感基因奠定基础。