Autoantibodies targeting deamidated epitopes in insulinoma antigen 2 as biomarkers in T1D

摘要 表位 这个 在 域名， 表位 (NEC)。 T1D， AS vbl.已 脱胺 CD+4+ 进化 生物标志物 后继 这个 不 压力， 评量 我们 域 复合材料 PTM 至 从… 在.期间 高风险 预测 在1型糖尿病(T1D)中，主要的T细胞抗原也是主要的体液抗原和一些 奥尼西德。目前，针对胰岛β-cel蛋白(Iabs)的自身抗体的累积测量 最明显的T1D风险生物标志物。胰岛素瘤抗原2(IA-2)，跨越胰岛素颗粒膜 β细胞是IAbs和T细胞反应的关键抗原靶点。IA-2含有NH_2流明 和COOH细胞质区域，大多数IA-2 IAb表位已绘制在该区域。然而， 存在于NH2腔区域，当胰岛素颗粒胞吐时，它暴露在细胞外 已在日本血吸虫病患者血清中鉴定出与IA-2Nec区特异性结合的胰岛自身抗体 易患LADA和酮病的糖尿病患者，其中一些人被归类为所有T1D IAB阴性。 对于IA-2Nec T细胞反应，抗原提呈细胞(高危)HLA-DR/DQ分子的配体有 显示源自I A-2Nec区，其中一些含有翻译后修饰(PTM) 谷氨酰胺残留(Q&gt；E)。四种不同的含有Q&gt；E残基的IA-2Nec多肽可以刺激 T1D患者外周血单个核细胞。因此，IA-2Nec结构域的原生和Ptm变体都是 作为T1D的关键抗原。 打破免疫耐受的PTM表位正在演变为T1D病因学的中心主题。 跟踪PTM可能特别有价值，因为它们可能是 在其他自身免疫性疾病中表现出来的疾病。我们假设IABS的目标是 在T1D患者的循环中可以检测到相同的IA-2Nec Q&gt；E T细胞表位。就像β细胞损伤一样 IA-2Nec结构域暴露所需的IA-2Nec Q&E表位特异性IAB可标记β-CELL 已知会加重PTM。我们的目标是检测和表征IA-2Nec Q&>；E特定的IAB和 它们在新发的T1D、糖尿病前期患者和普通人群中作为生物标记物的效用。 将开发针对IA-2Nec中包含去酰胺化残基的四个表位的IAB生物检测(最初) 并确定哪些表位和特定残基有助于体液免疫反应。 IA-2Nec Q&gt；E抗原探针将通过分子组装获得最佳灵敏度。其他推定 同样将在IA-2和其他T1D抗原中对表位进行评估。 利用我们优化的探针和检测方法，对这些IAB的预测价值进行评估和比较 不同队列中现有的生物标记物。跟踪观察糖尿病前期儿童的纵向血清样本 将对出生进行分析，以确定IA-2Nec Q&>E IAB相对于其他胰岛IAB的出现时间有多早 T1D进展。此外，IA-2Nec Q&gt；E IAB的流行率将在以下儿童队列中进行测试： 对于T1D和一般人群，估计IA-2Nec Q&gt；E I Abs对T1D风险的贡献 以及在一般人群筛查中将其用作生物标志物的潜力。 C L R C

Abstract epitopes the within domain, epitopes (Nec). T1D, As been deamidated CD4+ evolving Biomarkers subsequent the not stress, assess We domain Composite PTM to from during high-risk prediction In type 1 diabetes (T1D) the major T cell antigens are also predominant humoral antigens and some oincide. The cumulative measure of autoantibodies targeting islet β-cel proteins (IAbs) is presently most obust biomarker for T1D risk. Insulinoma antigen 2 (IA-2), spanning the insulin granule membrane the β-cell, is a key antigen target for both IAbs and T-cell responses. IA-2 contains a NH 2 luminal and a COOH cytoplasmic region where most IA-2 IAb epitopes have been mapped. However, exist in the NH 2 luminal domain, which upon i nsulin granule exocytosis, are exposed extracellularly Islet autoantibodies that specifically bind to the IA-2Nec region have been identified among sera from LADA and ketosis prone diabetic individuals, some of which were lassified as negative for all T1D IAbs. for IA-2Nec T cell responses, ligands of antigen-presenting cell (high risk) HLA-DR/DQ molecules have shown to derive from the I A-2Nec region, some of which contain post-translationally modified (PTM) glutamine residues (Q>E). Four distinct IA-2Nec peptides containing Q>E residues can stimulate PBMCs from T1D patients. As such, both the native and PTM variants of the IA-2Nec domain are as critical antigens in T1D. PTM epitopes that breach immune tolerance are evolving as a central theme in the etiology of T1D. that track PTMs may be of particular value as they may be very early surrogate markers for disease as has been shown in other autoimmune diseases. We hypothesize that IAbs targeting same IA-2Nec Q>E T cell epitopes can be detected in the circulation of T1D patients. As β-cell damage is required for exposure of the IA-2Nec domain, IAbs specific for IA-2Nec Q>E epitopes may mark β-cell known to exacerbate PTM. Our goal is to detect and characterize IA-2Nec Q>E-specific IAbs and their utility as biomarkers among new onset T1D, prediabetic individuals and in the general population. will develop IAb bioassays (initially) targeting four epitopes containing deamidated residues in the IA-2Nec and determine which epitopes and specific residues contribute to humoral immunoreactivity. IA-2Nec Q>E antigen probes will be molecularly assembled for optimal sensitivity. Other putative epitopes will likewise be evaluated in IA-2 and other T1D antigens. Using our optimized probes and assays the predictive value of these IAbs wil l be assessed and compared existing biomarkers among various cohorts. Longitudinal serum samples from pre-diabetic children followed birth will be analyzed to determine how early IA-2Nec Q>E IAbs appear with respect to other islet IAbs T1D progression. In addition, the prevalence of IA-2Nec Q>E IAbs will be tested in cohorts of children at for T1D and the general population to estimate the contribution of IA-2Nec Q>E I Abs to T1D risk and the potential for its use as a biomarker in general population-based screening. c l r c