Mutant PTPN22 in autoimmune mice

 描述(由申请人提供)：自身免疫是一种多基因疾病，通常涉及在许多遗传位点上存在支持自身免疫的等位基因。含有细胞内蛋白酪氨酸磷酸酶的PEST结构域的单核苷酸多态(SNP)PTPN22 R620W与许多自身免疫性疾病密切相关，包括系统性红斑狼疮、系统性硬化症、类风湿性关节炎、Graves病和1型糖尿病。目前还不清楚这种等位基因如何导致这些疾病。当存在该等位基因时，1型糖尿病(T1D)的发病率增加2-4倍。我们建议使用自发性1型糖尿病(T1D)的非肥胖糖尿病(NOD)小鼠模型来确定R620W、R619W的小鼠同源基因如何与疾病有关。该模型是理想的，因为在糖尿病患者的全基因组关联研究中发现的许多基因与NOD小鼠中导致T1D的基因相同或位于相同的途径上，包括MHC、胰岛素、CTLA-4和IL-2R途径。前自身免疫等位基因的存在可能是评估R619W等位基因对T1D影响的关键。我们已经成功地使用Crispr-Cas9技术对NOD受精胚胎进行了突变，并获得了两个独立的表达R619W变体的NOD小鼠品系。我们还获得了几个包含导致该基因移码突变的插入或缺失(INDELs)的品系。我们已经确定了所有的突变都是种系传播的，现在我们建议确定它们如何影响PTPN22的表达、免疫细胞的发育和动态平衡，以及最重要的是，疾病的进展。为此，我们将追求两个具体目标。AIM1将评估来自独立来源的NOD小鼠系的各种免疫细胞类型中突变PTPN22的表达水平。目标2的主要目标是确定R619W和Indel突变体是否改变了T1D的发生和进展。我们还将评估其对NOD小鼠免疫细胞发育、功能和动态平衡的影响。

 DESCRIPTION (provided by applicant): Autoimmunity is a multigenic disease that generally involves the presence of the pro- autoimmune allele at numerous genetic loci. There is a strong association between a single nucleotide polymorphism (SNP) in the PEST-domain containing intracellular protein tyrosine phosphatase, PTPN22 R620W, and numerous autoimmune diseases, including systemic lupus erythematosus, systemic sclerosis, rheumatoid arthritis, Graves diseases and Type 1 Diabetes. It is not understood how this allele contributes to these diseases. Type 1 diabetes (T1D) is increased in incidence by 2-4 fold when this allele is present. We propose to use the non-obese diabetic (NOD) mouse model of spontaneous type 1 diabetes (T1D) to determine how the mouse orthologue of R620W, R619W, contributes to disease. This model is ideal as many of the genes identified by genome- wide association studies in diabetic patients are the same or on the same pathway as those that contribute to T1D in NOD mice, including MHC, insulin, CTLA-4, and the IL- 2R pathway. The presence of the pro-autoimmune alleles may be critical to assess the impact of the R619W allele on T1D. We have successfully used the Crispr-Cas9 technology to mutate NOD fertilized embryos and produce 2 independent lines of NOD mice that express the R619W variant. We have also obtained several lines that incorporated insertions or deletions (indels) that caused frameshift mutations in this gene. We have ascertained all mutations are germline transmitted, and now propose to determine how they affect PTPN22 expression, immune cell development and homeostasis, and most importantly, disease progression. To this end we will pursue 2 Specific Aims. Aim1 will assess the level of expression of the mutant PTPN22 in various immune cell types from the independently derived NOD murine lines. The primary goal of Aim 2 is to determine whether the R619W and the indel mutants alter the incidence and progression of T1D. We will also assess its effect on immune cell development, function and homeostasis in NOD mice.