Ruttenberg Sarah M, Dhaoui Rakia, Kreutzer Adam G, Nowick James S
Department of Chemistry, University of California, Irvine, California, United States of America.
Department of Pharmaceutical Sciences, University of California, Irvine, California, United States of America.
PLoS One. 2025 Sep 8;20(9):e0331024. doi: 10.1371/journal.pone.0331024. eCollection 2025.
Anti-Aβ antibodies are important tools for identifying structural features of aggregates of the Aβ peptide and are used in many aspects of Alzheimer's disease (AD) research. Our laboratory recently reported the generation of a polyclonal antibody, pAb2AT-L, that is moderately selective for oligomeric Aβ over monomeric and fibrillar Aβ and recognizes the diffuse peripheries of Aβ plaques in AD brain tissue but does not recognize the dense fibrillar plaque cores. This antibody was generated against 2AT-L, a structurally defined Aβ oligomer mimic composed of three Aβ-derived β-hairpins arranged in a triangular fashion and covalently stabilized with three disulfide bonds. In the current study, we set out to determine if pAb2AT-L is neuroprotective against toxic aggregates of Aβ and found that pAb2AT-L protects human iPSC-derived neurons from Aβ42-mediated toxicity at molar ratios as low as 1:100 antibody to Aβ42, with a ratio of 1:25 almost completely rescuing cell viability. Few other antibodies have been reported to exhibit neuroprotective effects at such low ratios of antibody to Aβ. ThT and TEM studies indicate that pAb2AT-L delays but does not completely inhibit Aβ42 fibrillization at sub-stoichiometric ratios. The ability of pAb2AT-L to inhibit Aβ42 toxicity and aggregation at sub-stoichiometric ratios suggests that pAb2AT-L binds toxic Aβ42 oligomers and does not simply sequester monomeric Aβ42. These results further suggest that toxic oligomers of Aβ42 share significant structural similarities with 2AT-L.
抗淀粉样前体蛋白（Aβ）抗体是识别Aβ肽聚集体结构特征的重要工具，在阿尔茨海默病（AD）研究的许多方面都有应用。我们实验室最近报道了一种多克隆抗体pAb2AT-L的产生，该抗体对寡聚体Aβ的选择性高于单体和纤维状Aβ，能识别AD脑组织中Aβ斑块的弥散周边，但不能识别致密的纤维状斑块核心。这种抗体是针对2AT-L产生的，2AT-L是一种结构明确的Aβ寡聚体模拟物，由三个呈三角形排列的Aβ衍生β-发夹组成，通过三个二硫键共价稳定。在本研究中，我们着手确定pAb2AT-L是否对Aβ的毒性聚集体具有神经保护作用，结果发现pAb2AT-L能以低至1:100的抗体与Aβ42摩尔比保护人诱导多能干细胞衍生的神经元免受Aβ42介导的毒性，1:25的比例几乎能完全挽救细胞活力。很少有其他抗体被报道在如此低的抗体与Aβ比例下表现出神经保护作用。硫黄素T（ThT）和透射电子显微镜（TEM）研究表明，pAb2AT-L在亚化学计量比下会延迟但不会完全抑制Aβ42纤维化。pAb2AT-L在亚化学计量比下抑制Aβ42毒性和聚集的能力表明，pAb2AT-L结合有毒的Aβ42寡聚体，而不仅仅是隔离单体Aβ42。这些结果进一步表明，Aβ42的有毒寡聚体与2AT-L具有显著的结构相似性。
