ENHANCEMENT OF BIOMARKERS FOR TYPE 1 DIABETES

项目摘要/摘要 这项拟议的研究建立在我们之前14年来研究新免疫学的作用的成果的基础上 生物标志物和遗传因素为1型糖尿病(T1D)提供了更准确的分期。最近我们的 实验室发现了两种新的自身抗体生物标志物IA-2变异体特异性(IA-2var)和IA-2胞外 (IA-2eC)区自身抗体。特别是，我们鉴定了变异型特异性IA-2自身抗体(IA-2var) 在全长分子中引入氨基酸残基变体(Cys27，Gly608和Pro671)并开发 检测针对IA-2var分子的自身抗体和T细胞反应的新生物检测方法。我们提供了 初步数据显示，新发现的IA-2var自身抗体与HLADQ/DR相结合 基因分型显著改善了T1D患者一级亲属的风险预测(图4、5)。我们会 在糖尿病预防试验1(DPT-1)研究人群中使用这些生物标记物 基于表型较深的个体，纵向跟踪并以多个 与胰岛相关的自身抗体、人类白细胞抗原基因型别和其他危险因素(特定目标I)。DPT-1研究是一项 新的T1D生物标志物创新研究的独特资源，以及知识交流的催化剂 在这一群体中，已经进行了许多关于T1D预测的合作和许多关键研究。 我们将与Stephen Rich博士合作使用Illumina全球筛选阵列(GSA) 在T1D和其他自身免疫性疾病的遗传学方面开创了开创性的研究。我们假设 携带IA-2var自身抗体和GSA覆盖的基因中的SNPs的亲属进展为T1D， 包括HLADQ/DR标记变异体在内，对T1D进展有很高的预测性(特异性目标I)。 我们最近鉴定的IA-2自身抗体生物标记物的可用性导致了新T细胞的鉴定 IA-2胞外区内的表位(手稿正在审查中)。在电子分子模拟和 IA-2多肽与人类白细胞抗原II类分子的对接表明，这两种人类白细胞抗原都有高亲和力表位 DQ8和DR4对T1D具有显著的遗传风险(图8、9)。我们假设IA-2多肽 在IA-2var和胞外结构域内显示与疾病易感人类白细胞抗原的结合增强 分子将激发强大的CD4+T细胞反应(特定目标II)。这些疾病特异性T细胞可能是 免疫治疗的可行靶点，而抗原表位提供了抗原特异性治疗的可能性 预防或改善病程。这次调查将增加我们对……自然历史的了解 T1D，并推动开发和实施T1D预防试验。

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.