Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale F. Stagno d'Alcontres 31, 98166 Messina, Italy.
STmicroelectronics, Stradale Primosole, 50, 95121 Catania, Italy.
ACS Chem Neurosci. 2020 Apr 1;11(7):1013-1026. doi: 10.1021/acschemneuro.9b00549. Epub 2020 Mar 24.
An innovative approach to identify new conformational antigens of Aβ recognized by IgG autoantibodies as biomarkers of state and stage in Alzheimer's disease (AD) patients is described. In particular, through the use of bioinformatics modeling, conformational similarities between several Aβ forms and other amyloid-like proteins with F1 capsular antigen (Caf1) of were first found. pVIII M13 phage display libraries were then screened against YPF19, anti-Caf1 monoclonal antibody, and IgGs of AD patients, in alternate biopanning cycles of a so-called "double binding" selection. From the selected phage clones, one, termed 12III1, was found to be able to prevent Aβ-induced cytotoxicity in SH-SY5Y cells, as well as to promote disaggregation of preformed fibrils, to a greater extent with respect to wild-type phage (pC89). IgG levels detected by 12III1 provided a significant level of discrimination between diseased and nondemented subjects, as well as a good correlation with the state progression of the disease. These results give significant impact in AD state and stage diagnosis, paving the way for the development not only for an innovative blood diagnostic assay for AD precise diagnosis, progressive clinical assessment, and screening but also for new effective treatments.
本文描述了一种识别 Aβ 新构象抗原的创新方法，这些抗原被 IgG 自身抗体识别为阿尔茨海默病（AD）患者状态和阶段的生物标志物。具体来说，通过使用生物信息学建模，首先发现了几种 Aβ 形式与其他淀粉样蛋白之间的构象相似性，这些蛋白与 pVIII M13 噬菌体展示文库的 F1 荚膜抗原（Caf1）具有相似性。然后，针对 YPF19、抗 Caf1 单克隆抗体和 AD 患者的 IgGs，在所谓的“双重结合”选择的交替生物淘选循环中筛选噬菌体文库。从选定的噬菌体克隆中，发现一个称为 12III1 的克隆能够在 SH-SY5Y 细胞中预防 Aβ 诱导的细胞毒性，并且能够更有效地促进原纤维的解聚，相对于野生型噬菌体（pC89）而言。通过 12III1 检测到的 IgG 水平在疾病和非痴呆患者之间提供了显著的区分水平，并且与疾病的状态进展具有良好的相关性。这些结果在 AD 状态和阶段诊断方面具有重要意义，为 AD 精确诊断、渐进性临床评估和筛选的创新血液诊断检测方法的开发以及新的有效治疗方法的开发铺平了道路。
