The toxicity of antiprion antibodies is mediated by the flexible tail of the prion protein
The toxicity of antiprion antibodies is mediated by the flexible tail of the prion protein
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DOI：
10.1038/nature12402
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发表时间：
2013-09-05
期刊：
影响因子：
64.8
通讯作者：
Aguzzi, Adriano
中科院分区：
文献类型：
--
作者：
Sonati, Tiziana;Reimann, Regina R.;Aguzzi, Adriano
朊病毒感染导致致命的神经变性。这一过程需要细胞朊病毒蛋白（PrPC;参考文献1），它含有一个球形结构域，与一个长的氨基近端柔性尾相连（2）。在这里，我们描述了快速神经毒性小鼠和小脑器官型培养切片暴露于配体靶向α 1和α 3螺旋的PrPC球状域。配体包括7种不同的单克隆抗体（3）、单价Fab（1）片段和重组单链可变片段微型抗体。与朊病毒感染相似（4-6），球状结构域配体的毒性需要神经元PrPC，PrPC过表达会加剧其毒性，与钙蛋白酶激活相关，并被钙蛋白酶抑制剂拮抗。神经变性伴随着活性氧簇的爆发，并被抗氧化剂抑制。此外，超氧化物生成酶NOX 2（也称为CYBB）的基因切除保护小鼠免受球状结构域配体毒性。我们还发现，神经毒性是防止删除的八肽重复内的灵活的尾巴。这些缺失没有明显损害球状域抗体结合，表明需要柔性尾部来传递源自球状域的毒性信号并触发氧化应激和钙蛋白酶激活。支持这一观点，各种八肽配体不仅对小脑器官型培养切片和小鼠无害，而且还防止了球状结构域配体的毒性，同时不干扰它们的结合。我们的结论是，PrPC由两个功能不同的模块，与球状域和灵活的尾巴发挥监管和执行功能，分别。八肽配体还延长了表达毒性PrPC突变体PrP（Lambda 94-134）的小鼠的寿命（7），表明柔性尾在两种不同的PrPC相关病症中介导毒性。柔性尾介导的毒性可能在进一步的朊病毒病理学中发挥作用，例如携带额外八肽的人类的家族性克雅氏病。
Prion infections cause lethal neurodegeneration. This process requires the cellular prion protein (PrPC; ref. 1), which contains a globular domain hinged to a long amino-proximal flexible tail(2). Here we describe rapid neurotoxicity in mice and cerebellar organotypic cultured slices exposed to ligands targeting the alpha 1 and alpha 3 helices of the PrPC globular domain. Ligands included seven distinct monoclonal antibodies(3), monovalent Fab(1) fragments and recombinant single-chain variable fragment miniantibodies. Similar to prion infections(4-6), the toxicity of globular domain ligands required neuronal PrPC, was exacerbated by PrPC overexpression, was associated with calpain activation and was antagonized by calpain inhibitors. Neurodegeneration was accompanied by a burst of reactive oxygen species, and was suppressed by antioxidants. Furthermore, genetic ablation of the superoxide-producing enzyme NOX2 (also known as CYBB) protected mice from globular domain ligand toxicity. We also found that neurotoxicity was prevented by deletions of the octapeptide repeats within the flexible tail. These deletions did not appreciably compromise globular domain antibody binding, suggesting that the flexible tail is required to transmit toxic signals that originate from the globular domain and trigger oxidative stress and calpain activation. Supporting this view, various octapeptide ligands were not only innocuous to both cerebellar organotypic cultured slices and mice, but also prevented the toxicity of globular domain ligands while not interfering with their binding. We conclude that PrPC consists of two functionally distinct modules, with the globular domain and the flexible tail exerting regulatory and executive functions, respectively. Octapeptide ligands also prolonged the life of mice expressing the toxic PrPC mutant(7), PrP(Lambda 94-134), indicating that the flexible tail mediates toxicity in two distinct PrPC-related conditions. Flexible tail-mediated toxicity may conceivably play a role in further prion pathologies, such as familial Creutzfeldt-Jakob disease in humans bearing supernumerary octapeptides.