Transactive response DNA-binding protein of 43 kilodaltons (TDP-43) is a 414 amino acid protein that under physiologic conditions localizes to the nucleus and participates in the regulation of RNA metabolism through two RNA recognition motifs (RRM1 and RRM2). In neurodegenerative diseases, TDP-43 may become hyperphosphorylated, ubiquitinated, and aggregate into cytoplasmic inclusions. TDP-43 is now well-characterized as a pathologic protein of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration with TDP-43 proteinopathy (FTLD-TDP). Additionally, a common TDP-43 proteinopathy arising outside of the context of ALS and FTLD-TDP has been recently described, termed “limbic predominant age-related TDP-43 encephalopathy (LATE).” In the current study, two novel mouse-derived monoclonal antibodies, 2G11 and 2H1, raised against an epitope within the RRM2 domain of TDP-43 (residues 198–216), were characterized for specificity and immunohistochemical application in human brain from cases of Alzheimer’s disease (AD), Lewy Body Disease (LBD), amyotrophic lateral sclerosis (ALS), and frontotemporal lobe degeneration with TDP-43 inclusions (FTLD-TDP). Immunoblot analysis of these antibodies in HEK293T cells revealed efficient detection of intact human TDP-43 protein, and in N2A cells showed no reactivity for mouse TDP-43. Immunohistochemically applied to formalin-fixed paraffin-embedded tissues, 2G11 and 2H1 robustly identified the classic inclusions of ALS and FTLD-TDP, and efficaciously provided a diagnosis of LATE in cases of AD and LBD. These novel antibodies label aberrant intracytoplasmic protein inclusions without relying on hyperphosphorylated epitopes, and provide elegant discrimination between TDP-43 and tau neurofibrillary tangles within neurodegenerative comorbidity.

43 千道尔顿的反式反应 DNA 结合蛋白 (TDP-43) 是一种 414 个氨基酸的蛋白质，在生理条件下定位于细胞核，并通过两个 RNA 识别基序（RRM1​​ 和 RRM2）参与 RNA 代谢的调节。在神经退行性疾病中，TDP-43 可能会过度磷酸化、泛素化并聚集成细胞质内含物。TDP-43 现在被很好地表征为肌萎缩侧索硬化 (ALS) 和额颞叶变性伴 TDP-43 蛋白病 (FTLD-TDP) 的病理蛋白。此外，最近描述了一种在 ALS 和 FTLD-TDP 背景之外出现的常见 TDP-43 蛋白病，称为“边缘为主的年龄相关性 TDP-43 脑病 (LATE)”。在目前的研究中，两种新型小鼠来源的单克隆抗体 2G11 和 2H1，针对 TDP-43 的 RRM2 结构域内的表位（残基 198-216），特征在于特异性和免疫组织化学在人脑中的应用，这些病例来自阿尔茨海默病 (AD)、路易体病 (LBD)、肌萎缩侧索硬化症 (ALS) )，以及额颞叶变性与 TDP-43 包涵体 (FTLD-TDP)。HEK293T 细胞中这些抗体的免疫印迹分析揭示了完整人 TDP-43 蛋白的有效检测，并且在 N2A 细胞中显示出对小鼠 TDP-43 没有反应性。免疫组织化学应用于福尔马林固定石蜡包埋的组织，2G11 和 2H1 有力地鉴定了 ALS 和 FTLD-TDP 的经典内含物，并有效地提供了 AD 和 LBD 病例的 LATE 诊断。这些新型抗体在不依赖过度磷酸化表位的情况下标记异常的胞质内蛋白包涵体，