ENHANCEMENT OF BIOMARKERS FOR TYPE 1 DIABETES

项目总结/摘要 这项拟议的研究建立在我们之前14年的成就之上，这些成就调查了新的免疫学 生物标志物和遗传因素，提供更准确的1型糖尿病（T1 D）分期。最近我们 一个实验室发现了两种新的自身抗体生物标志物，IA-2变体特异性（IA-2 var）和IA-2细胞外 （IA-2 ec）结构域自身抗体。特别地，我们鉴定了变体特异性IA-2自身抗体（IA-2 var）， 在全长分子中掺入氨基酸残基变体（Cys 27、Gly 608和Pro671），并开发 检测针对IA-2 var分子的自身抗体和T细胞应答的新生物测定法。我们提供 初步数据表明，新鉴定的IA-2 var自身抗体与HLADQ/DR结合， 基因型，显着提高T1 D患者的一级亲属的风险预测（图4，5）。我们将 在1型糖尿病预防试验（DPT-1）研究人群中使用这些生物标志物， 基于深度表型化的个体，纵向跟踪并表征多个 胰岛相关自身抗体、HLA基因型和其他风险因素（特异性目标I）。DPT-1研究是一项 新T1 D生物标志物创新研究的独特资源，以及知识交流的催化剂 和合作，并在这一人群中进行了许多关于T1 D预测的重要研究。 我们将与Stephen Rich博士合作使用Illumina全球筛查阵列（GSA）， 开创了T1 D和其他自身免疫性疾病遗传学的开创性研究。我们假设 在携带IA-2 var自身抗体和GSA覆盖的基因中的SNP的亲属中进展为T1 D， 包括HLADQ/DR标记变体，高度预测T1 D进展（特异性目的I）。 我们最近鉴定的IA-2自身抗体生物标志物的可用性导致了新的T细胞的鉴定。 IA-2细胞外结构域内的表位（正在审查的手稿）。计算机分子建模和 IA-2肽与HLA II类分子的对接表明， DQ 8和DR 4可导致T1 D的显著遗传风险（图8、9）。我们假设IA-2肽 在IA-2 var和细胞外结构域内，其表现出与疾病易感性HLA的增强结合 分子将引发强烈的CD 4 + T细胞应答（特异性目的II）。这些疾病特异性T细胞可能是 表位提供了抗原特异性治疗的潜力， 预防或改善疾病进程。这项调查将增加我们对自然历史的了解。 T1 D，并推动T1 D预防试验的开发和实施。

PROJECT SUMMARY/ABSTRACT The proposed research builds on our prior 14-year achievements investigating the role of new immunologic biomarkers and genetic factors that provide a more accurate staging of Type 1 diabetes (T1D). Recently our laboratory discovered two novel autoantibody biomarkers, IA-2 variant-specific (IA-2var) and IA-2 extracellular (IA-2ec) domain autoantibodies. In particular, we identified variant-specific IA-2 autoantibodies (IA-2var) incorporating amino acid residue variants (Cys27, Gly608 and Pro671) in the full length molecule and developed new bioassays detecting autoantibodies and T cell responses against the IA-2var molecule. We provided preliminary data indicating that the newly identified IA-2var autoantibodies, in combination with HLADQ/DR genotypes, significantly improves risk prediction in first-degree relatives of T1D patients (Figure 4, 5). We will utilize these biomarkers in the population of the Diabetes Prevention Trial-Type 1 (DPT-1) Study, which is based on deeply phenotyped individuals, longitudinally followed and characterized with respect to multiple islet-related autoantibodies, HLA genotypes, and other risk factors (Specific Aim I). The DPT-1 Study is a unique resource for innovative research on new T1D biomarkers, and a catalyst for the exchange of knowledge and collaboration and many critical studies on T1D prediction have been conducted in this population. We will be using the Illumina Global Screening Array (GSA) in collaboration with Dr. Stephen Rich who pioneered seminal studies in the genetics of T1D and other autoimmune disorders. We hypothesize that the progression to T1D in relatives carrying IA-2var autoantibodies and SNPs in genes covered by the GSA, including HLA DQ/DR-tagging variants, are highly predictive of T1D progression (Specific Aim I). The availability of our recently identified IA-2 autoantibody biomarkers led to the identification of new T cell epitopes within the IA-2 extracellular domain (manuscript under review). In silico molecular modeling and docking of IA-2 peptides to HLA class II molecules suggests that there are high affinity epitopes for both HLA DQ8 and DR4 which confer significant genetic risk for T1D (Figure 8, 9). We hypothesize that IA-2 peptides within the IA-2var and the extracellular domain that exhibit enhanced binding to disease susceptible HLA molecules will elicit robust CD4+ T cell responses (Specific Aim II). These disease-specific T cells could be feasible targets of immunotherapies while the epitopes offer the potential of antigen specific therapies to prevent or ameliorate the disease course. This investigation will add to our knowledge of the natural history of T1D and motivate the development and implementation of prevention trials for T1D.