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（由申请人提供）：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复杂的相互关系，而这些基因是自身免疫性破坏的基础。虽然确实存在大量证据支持这一观点（我们自己也相信这是真的），但自身免疫性 β 细胞破坏的确切机制是此外，每个方面（即细胞、基因）在此过程中的相对贡献在很大程度上仍然未知。T1D 相关易感性等位基因的机制研究因多基因遗传而变得复杂。因此，由于缺乏群体力量以及无法隔离个体的功能影响，研究受到严重阻碍。 在这里，我们提出了一种解决方案，该解决方案利用创新的同基因模式，利用尖端技术来研究特定的遗传风险变异如何促进免疫失调，从而导致细胞毒性 CD8+。我们研究了 PTPN22 中的基因调控缺陷促进 i) 免疫原性 DC，ii) TH1 反应，iii) 胰腺血管炎症和 CTL。归巢，以及 iv) 针对 β 细胞的致病性 CTL 活性，加上激活诱导的 CTL 死亡的减少：这些租户中的每一个都构成了本次资助的目标。此外，我们认为，当免疫细胞和内皮细胞对激活过度敏感时，缺陷会充分发挥潜力。在这里，我们将利用一种新的实验管道，其中 PTPN22R（T1D 耐药）、PTPN22W（T1D 易感）。或 PTPN22 缺失 (PTPN22-/-) 等位基因由诱导多能干细胞 [iPSC] 改造的同基因人类免疫和内皮细胞携带。 iPSC 系统可以精确控制 T1D 疾病等位基因，其中易感等位基因可以被耐药等位基因取代。等位基因（反之亦然）提供恒定的遗传背景，在此基础上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， 以类似于转基因小鼠研究的方式，这里提出的这个系统将提供前所未有的能力，在同基因条件下探究分子和细胞相互作用，以提供对 PTPN22 等位基因如何调节 T1D 发病机制的各个步骤以及这些步骤如何相互关联的机制理解。重要的是，这项研究还将为未来使用这种创新策略研究单个或多个 T1D 易感基因奠定基础。