PDF(Pubmed)
Abstract：
Progressive multifocal leukoencephalopathy (PML) is a frequent neurological complication in immunosuppressed patients. PML is caused by the JC virus (JCV), a neurotropic DNA polyomavirus that infects oligodendrocytes and astrocytes, causing inflammation and demyelination which lead to neurological dysfunction. The pathogenesis of PML is poorly understood due to the lack of in vitro or animal models to study mechanisms of disease as the virus most efficiently infects only human cells. We developed a human-derived brain organotypic system (also called brain organoid) to model JCV infection. The model was developed by using human-induced pluripotent stem cells (iPSC) and culturing them in 3D to generate an organotypic model containing neurons, astrocytes, and oligodendrocytes which recapitulates aspects of the environment of the human brain. We infected the brain organoids with the JCV MAD4 strain or cerebrospinal fluid of a patient with PML. The organoids were assessed for evidence of infection by qPCR, immunofluorescence, and electron microscopy at 1, 2, and 3 weeks post-exposure. JCV infection in both JCV MAD4 strain and PML CSF-exposed brain organoids was confirmed by immunocytochemical studies demonstrating viral antigens and electron microscopy showing virion particles in the nuclear compartment of oligodendrocytes and astrocytes. No evidence of neuronal infection was visualized. Infection was also demonstrated by JCV qPCR in the virus-exposed organoids and their media. In conclusion, the brain organoid model of JCV infection establishes a human model suitable for studying the mechanisms of JCV infection and pathogenesis of PML and may facilitate the exploration of therapeutic approaches.
摘要：
进行性多灶性白质脑病（PML）是免疫抑制患者常见的神经系统并发症。PML是由JC病毒（JCV）引起的，一种感染少突胶质细胞和星形胶质细胞的嗜神经DNA多瘤病毒，引起炎症和脱髓鞘，导致神经功能障碍。由于缺乏体外或动物模型来研究疾病机制，因此对PML的发病机理知之甚少，因为病毒最有效地仅感染人类细胞。我们开发了人类来源的脑器官型系统（也称为脑类器官）来模拟JCV感染。该模型是通过使用人类诱导的多能干细胞（iPSC）并在3D中培养它们以生成包含神经元的器官型模型来开发的，星形胶质细胞,以及概括人脑环境的少突胶质细胞。我们用PML患者的JCVMAD4菌株或脑脊液感染了脑类器官。通过qPCR评估类器官的感染证据，免疫荧光，暴露后1、2和3周的电子显微镜检查。通过免疫细胞化学研究证实了JCVMAD4菌株和PMLCSF暴露的脑类器官中的JCV感染，这些研究表明病毒抗原和电子显微镜显示少突胶质细胞和星形胶质细胞的核室中的病毒体颗粒。没有可见神经元感染的证据。在暴露于病毒的类器官及其培养基中,通过JCVqPCR也证实了感染。总之,JCV感染的脑类器官模型建立了一个适用于研究JCV感染机制和PML发病机制的人类模型，可能有助于探索治疗方法。
