Fuctional Analyses of Autoimmune Disease Variants

该项目，自身免疫疾病变异的功能分析，重点是在人类和小鼠中的三个1型糖尿病（T1 D）易感基因座，CTLA 4，PTPN 22和CD 226。T1 D是儿童的一种主要疾病，发病率不明原因地稳步上升，5岁以下儿童确诊人数不断增加。所提出的研究完全整合到PPG活动和目标中，并提供了一个平台，以继续剑桥和波士顿的Pis之间的高效，相互依赖和协同合作，旨在了解T1 D和自身免疫性疾病基因变体的生物学效应（我们已经使用遗传图谱识别）。使用来自遗传可选择的当地健康志愿者的主要来源（剑桥BioResource）的新鲜血液样品离体研究TlD基因变体，并在TlD的精确工程化NOD小鼠模型中体内研究TlD基因变体。 Ctla 4、Ptpn 22和Cd 226 KO等位基因将用于开发NOD菌株以模拟人T1 D。增加T1 D的小鼠Ptpn 22变体将成为PTPN 22基因机制研究的焦点，PTPN 22基因是影响多种人类自身免疫性疾病的分子途径的一部分。在Ptpn 22处具有易感性等位基因的T细胞具有较高的活化阈值，并且在群体水平上，当离体刺激时，较少的细胞产生IL-2。由于人类和小鼠IL-2通路中的基因变体都影响T1 D易感性，因此提出了研究两种物种中PTPN 22和IL-2通路之间的基因-基因相互作用的实验。初步数据表明，CTLA-4的易感性等位基因降低了可溶性CTLA-4的表达，降低了Tcl 3被激活的可能性。可溶性CTLA-4在原代T细胞和细胞系中的过表达将是用于研究可溶性CTLA-4影响T细胞活化中的早期事件的机制的一种方法。由于PTPN 22和CTLA-4基因的变体被认为可以改变T细胞活化，因此将研究人类和小鼠中PTPN 22和CTLA-4途径之间的基因-基因相互作用。

The project, Functional Analyses of Autoimmune Disease Variants, is focused on three type 1 diabetes (T1D) susceptibility loci, CTLA4, PTPN22 and CD226 in humans and in mice. T1D is a major disease of children with an unexplained steady rise in incidence and increasing numbers of children diagnosed under age 5 years. The research proposed is fully integrated into the PPG activities and goals, and provides a platform to continue the highly productive, interdependent and synergistic collaboration amongst the Pis in Cambridge and Boston aimed at understanding the biological effects of T1D and autoimmune disease gene variants (that we have identified using genetic mapping). T l D gene variants will be studied ex vivo using fresh blood samples from a major resource of genetically-selectable, local healthy volunteers (the Cambridge BioResource) and in vivo, in precisely engineered NOD mouse models of T1D. The Ctla4, Ptpn22 and Cd226 KO alleles will be used to develop NOD strains to model human T1D. A mouse Ptpn22 variant that increases T1D will be a focus of mechanistic studies on the PTPN22 gene, which is part of a molecular pathway that affects multiple human autoimmune diseases. T cells having the susceptibility allele at Ptpn22 have a higher threshold of activation and at a population level fewer of the cells produce IL-2 when stimulated ex vivo. Since both human and mouse gene variants in the IL-2 pathway affect T1D susceptibility, experiments to study gene-gene interactions between the PTPN22 and IL-2 pathways in both species are proposed. Preliminary data indicate that the susceptibility allele at CTLA4, which decreases the expression of soluble CTLA-4, reduces the probability that Tregs will be activated. Overexpression of soluble CTLA-4 in primary T cells and cell lines will be one approach used to study the mechanism by which soluble CTLA-4 affects early events in T cell activation. Since variants at both the PTPN22 and CTLA-4 genes are proposed to alter T cell activation, gene-gene interactions between the PTPN22 and CTLA-4 pathways in both humans and mice will be investigated.