III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Kidney Int. 2023 Feb;103(2):297-303. doi: 10.1016/j.kint.2022.09.008. Epub 2022 Sep 30.
Antibody-mediated autoimmune pathologies like membranous nephropathy are difficult to model, particularly in the absence of local target antigen expression in model organisms such as mice and rats; as is the case for phospholipase A2 receptor 1 (PLA2R1), the major autoantigen in membranous nephropathy. Here, we generated a transgenic mouse line expressing the full-length human PLA2R1 in podocytes, which has no kidney impairment after birth. Beginning from the age of three weeks, these mice spontaneously developed anti-human PLA2R1 antibodies, a nephrotic syndrome with progressive albuminuria and hyperlipidemia, and the typical morphological signs of membranous nephropathy with granular glomerular deposition of murine IgG in immunofluorescence and subepithelial electron-dense deposits by electron microscopy. Importantly, human PLA2R1-expressing Rag2 mice, which lack mature and functioning B and T lymphocytes, developed neither anti-PLA2R1 antibodies nor proteinuria. Thus, our work demonstrates that podocyte expression of human PLA2R1 can induce membranous nephropathy with an underlying antibody-mediated pathogenesis in mice. Importantly, this antibody-mediated model enables proof-of-concept evaluations of antigen-specific treatment strategies, e.g., targeting autoantibodies or autoantibody-producing cells, and may further help understand the autoimmune pathogenesis of membranous nephropathy.
抗体介导的自身免疫性疾病,如膜性肾病,难以建模,尤其是在缺乏模型生物(如小鼠和大鼠)中局部靶抗原表达的情况下;就磷脂酶 A2 受体 1 (PLA2R1) 而言,它是膜性肾病的主要自身抗原。在这里,我们生成了一种在足细胞中表达全长人 PLA2R1 的转基因小鼠系,该小鼠系在出生后没有肾脏损伤。从三周大开始,这些小鼠自发产生抗人 PLA2R1 抗体,出现肾病综合征伴进行性白蛋白尿和高血脂症,以及免疫荧光显示颗粒状肾小球 IgG 沉积和电镜下上皮下电子致密沉积物的典型膜性肾病形态学特征。重要的是,缺乏成熟和功能正常的 B 和 T 淋巴细胞的人 PLA2R1 表达 Rag2 小鼠既没有产生抗 PLA2R1 抗体,也没有蛋白尿。因此,我们的工作表明,人 PLA2R1 在足细胞中的表达可在小鼠中诱导以抗体为基础的发病机制的膜性肾病。重要的是,这种抗体介导的模型能够对抗原特异性治疗策略(例如针对自身抗体或产生自身抗体的细胞)进行概念验证评估,并且可能进一步有助于理解膜性肾病的自身免疫发病机制。