Laboratory of Gene Therapy, Department of Biochemistry, College of Life Sciences, Shaanxi Normal University, Shaanxi, P.R. China.
Department of Pathology, University of Utah, Salt Lake City, Utah, USA.
J Neuropathol Exp Neurol. 2024 Aug 1;83(8):655-669. doi: 10.1093/jnen/nlae042.
The RNA/DNA-binding protein TDP-43 plays a pivotal role in the ubiquitinated inclusions characteristic of TDP-43 proteinopathies, including most cases of frontotemporal lobar degeneration (FTLD-TDP) and Alzheimer disease (AD). To understand the mechanisms of pathological TDP-43 processing and identify potential biomarkers, we generated novel phosphorylation-independent monoclonal antibodies (MAbs) using bacteria-expressed human full-length recombinant TDP-43. Remarkably, we identified a distinctive MAb, No. 9, targeting an epitope in amino acid (aa) region 311-360 of the C-terminus. This antibody showed preferential reactivity for pathological TDP-43 inclusions, with only mild reactivity for normal nuclear TDP-43. MAb No. 9 revealed more pathology in FTLD-TDP type A and type B brains and in AD brains compared to the commercial p409/410 MAb. Using synthetic phosphorylated peptides, we also obtained MAbs targeting the p409/410 epitope. Interestingly, MAb No. 14 was found to reveal additional pathology in AD compared to the commercial p409/410 MAb, specifically, TDP-43-immunopositive deposits with amyloid plaques in AD brains. These unique immunopositivities observed with MAbs No. 9 and No. 14 are likely attributed to their conformation-dependent binding to TDP-43 inclusions. We expect that this novel set of MAbs will prove valuable as tools for future patient-oriented investigations into TDP-43 proteinopathies.
RNA/DNA 结合蛋白 TDP-43 在 TDP-43 蛋白病的泛素化包含物中发挥关键作用，包括大多数额颞叶变性（FTLD-TDP）和阿尔茨海默病（AD）病例。为了了解病理性 TDP-43 加工的机制并确定潜在的生物标志物，我们使用细菌表达的全长人重组 TDP-43 生成了新型非磷酸依赖性单克隆抗体（MAb）。值得注意的是，我们鉴定了一种独特的 MAb，编号为 9，针对 C 端氨基酸（aa）区域 311-360 中的表位。该抗体对病理性 TDP-43 包含物具有优先反应性，对正常核 TDP-43 仅有轻微反应性。与商业 p409/410 MAb 相比，MAb No. 9 在 FTLD-TDP 型 A 和 B 脑和 AD 脑中显示出更多的病变。使用合成磷酸化肽，我们还获得了针对 p409/410 表位的 MAb。有趣的是，与商业 p409/410 MAb 相比，MAb No. 14 被发现显示出 AD 中的更多病变，特别是在 AD 脑中 TDP-43 免疫阳性沉积与淀粉样斑块。与 MAb No. 9 和 No. 14 观察到的这些独特的免疫阳性可能归因于它们对 TDP-43 包含物的构象依赖性结合。我们期望这组新的 MAb 将成为未来以患者为导向的 TDP-43 蛋白病研究的有价值工具。
