Antibody-Detection-by-Agglutination-PCR (ADAP): An Ultra-Sensitive, High-Throughput, Multiplexable Tool for T1D Diagnosis and Monitoring

项目总结/摘要 准确及时地检测循环中的胰岛抗原自身抗体对这两项研究都至关重要 1型糖尿病（T1 D）患者的临床护理。然而，这一衡量标准在不同地区仍然存在很大差异。 市售的测定，并且此类测定也可能不能充分检测特别低但临床相关的 循环自身抗体水平。这一不足导致错失了及时启动 最适当的治疗方案，并支持急需的研究，以改善新的疾病， 干预措施。此外，T1 D的大规模公共卫生筛查工作受到低通量的阻碍 当前生物测定的性质和/或它们对昂贵和专用仪器的要求。我们已经开发 一种基于PCR的专利技术，称为抗体凝集PCR检测（ADAP）。ADAP 是一种高通量测定法，可用于同时检测多种抗体，同时仅需要非常 少量患者血清（2 μL）。ADAP还能检测出自身抗体，灵敏度提高1,000至10,000倍。 与目前使用的免疫测定和放射免疫测定相比， PCR（qPCR）工作流程使用许多医院、诊所和公共卫生部门现有的仪器 筛选网站重要的是，ADAP代表了与效率较低的PCR驱动平台的重大偏离， 免疫-PCR，克服了这类测定固有的许多缺陷，以提供高通量，超灵敏， 稳健、可靠和特异的检测方法。 在第一阶段的申请中，我们建议开发一种基于ADAP的检测试剂盒，用于检测四种自身抗体 这是T1 D诊断的基础。相应的GAD 65、IA-2、胰岛素和ZnT 8抗原将通过 与独特的单链DNA序列缀合。抗原与其同源物孵育后的凝集 抗体使DNA序列彼此靠近。然后提供适当的“桥寡核苷酸”， 连接，得到可扩增的DNA双链体。这种抗原-自身抗体结合事件提供了PCR扩增子， 能够以最小的背景信号进行超灵敏检测。接下来我们将使用这些经过适当验证的试剂 用于在诊断之前和之后分析T1 D背景下的患者血清样品。最后，越来越多的 应当理解，高亲和力自身抗体是疾病严重程度的优先指标。在预期的诊断 为了证明这一新发现的价值，我们还建议创建一种创新的ADAP检测变体，我们将其称为μADAP， 能够高通量定量高亲和力自身抗体。这种测定的部署可以允许更多的 准确确定T1 D预后，并能够改善治疗干预的选择。 总之，我们寻求建立ADAP T1 D检测试剂盒，不仅作为当前T1 D诊断的有效替代品， 平台，但一个显着扩大能力方面的灵敏度，速度，再现性和 多路复用，可以成本有效地集成到现有的实验室和临床工作流程。

PROJECT SUMMARY/ABSTRACT Accurate and timely detection of circulating autoantibodies against pancreatic islet antigens is critical to both research and clinical care for patients with type 1 diabetes (T1D). However this measurement remains highly variable across commercially available assays, and such assays also may not adequately detect particularly low but clinically relevant levels of circulating autoantibodies. This deficit translates into missed opportunities for both the timely initiation of the most appropriate treatment regimens and to support much needed research into novel and improved disease-modifying interventions. Additionally, large-scale public health screening efforts for T1D are hampered by the low throughput nature of current bioassays, and/or their requirement for expensive and specialized instrumentation. We have developed a proprietary patent-pending PCR-based technology termed Antibody Detection by Agglutination-PCR (ADAP). ADAP is a high-throughput assay that can be used for simultaneous detection of multiple antibodies while requiring only a very small amount of patient serum (2 μL). ADAP also detects autoantibodies with 1,000 to 10,000 times greater sensitivity than the currently used immunometric and radio-immuno assays, and can be readily integrated into common quantitative PCR (qPCR) workflows using pre-existing instrumentation that is available at many hospitals, clinics and public health screening sites. Importantly, ADAP represents a significant departure from less effective PCR-driven platforms such as immuno-PCR, overcoming many of the deficits inherent to this class of assays to afford a high-throughput, ultrasensitive, robust, reliable, and specific detection method. In this Phase 1 application, we propose to develop an ADAP-based assay kit for detection of the four autoantibodies that form the basis for T1D diagnosis. The corresponding GAD65, IA-2, insulin, and ZnT8 antigens will be barcoded by conjugation to unique single-stranded DNA sequences. Agglutination of an antigen upon incubation with its cognate antibody brings the DNA sequences near to each other. An appropriate “bridge oligo” is then supplied which, upon ligation, affords an amplifiable DNA duplex. This antigen-autoantibody binding event provides a PCR amplicon that enables ultrasensitive detection with minimal background signal. Next we will use these appropriately validated reagents for analysis of patient serum samples in the context of T1D, both before and after diagnosis. Finally, it is increasingly appreciated that high-affinity autoantibodies are privileged indicators of disease severity. In anticipation of the diagnostic value of this new finding, we also propose to create an innovative variant of the ADAP assay which we term μADAP to enable high throughput quantification of high-affinity autoantibodies. Deployment of such an assay may allow more accurate determination of T1D prognosis, and enable improved choices of therapeutic interventions. In summary, we seek to establish the ADAP T1D assay kit not only as an effective alternative to current T1D diagnostic platforms, but one with significantly expanded capabilities in terms of sensitivity, speed, reproducibility and multiplexability that can be cost-effectively integrated into existing laboratory and clinical workflows.