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基因座存在促自身免疫等位基因。含有细胞内蛋白酪氨酸磷酸酶的PEST结构域中的单核苷酸多态性（SNP）PTPN 22 R620 W与许多自身免疫性疾病（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）之间存在强关联。目前尚不清楚这种等位基因如何导致这些疾病。当该等位基因存在时，1型糖尿病（T1 D）的发病率增加2-4倍。我们建议使用自发性1型糖尿病（T1 D）的非肥胖糖尿病（NOD）小鼠模型来确定R620 W的小鼠直系同源物R619 W如何促成疾病。该模型是理想的，因为在糖尿病患者中通过全基因组关联研究鉴定的许多基因与在NOD小鼠中促成T1 D的那些基因相同或在相同途径上，包括MHC、胰岛素、CTLA-4和IL-2 R途径。促自身免疫等位基因的存在对于评估R619 W等位基因对T1 D的影响可能至关重要。我们已经成功地使用Crispr-Cas9技术来突变NOD受精胚胎，并产生了表达R619 W变体的2个独立的NOD小鼠系。我们还获得了几个包含插入或缺失（indels）的品系，这些插入或缺失导致该基因的移码突变。我们已经确定所有突变都是种系传播的，现在建议确定它们如何影响PTPN 22表达、免疫细胞发育和稳态，以及最重要的是疾病进展。为此，我们将坚持两个具体目标。Aim 1将评估突变体PTPN 22在来自独立衍生的NOD鼠系的各种免疫细胞类型中的表达水平。目的2的主要目标是确定R619 W和indel突变体是否改变T1 D的发病率和进展。我们还将评估其对NOD小鼠免疫细胞发育、功能和稳态的影响。

 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.