Identification of Immune modulators associated with JC virus replication

描述(申请人提供)：进行性多灶性白质脑病(PML)是由人类多瘤病毒JC病毒(JCV)引起的一种致命的中枢神经系统脱髓鞘疾病。PML曾是一种罕见的老年人疾病，最常见于艾滋病患者，最近也出现在其他严重免疫抑制患者中，包括接受免疫抑制治疗的多发性硬化症、克罗恩病、类风湿性关节炎和B细胞淋巴瘤。据认为，免疫抑制与有效的新型免疫抑制剂，包括抗CD20分子，利妥昔单抗，允许JC病毒在患者体内复制，从而导致PML的发展。我们推测，利妥昔单抗可能通过导致某些细胞因子或其他可溶性介质的释放，从而在感染的星形胶质细胞中触发JCV复制，从而间接导致PML的发生。为了支持这一假设，我们的初步数据发现，从用利妥昔单抗处理的PBMC获得的条件培养液增加了星形胶质细胞中JCV的复制。我们还通过JCV感染星形胶质细胞的微阵列分析和PML脑组织的免疫组织化学检测到细胞因子、细胞外基质蛋白和其他细胞因子的上调，进一步支持了这一假说。在这项研究中，我们提出了一套细胞生物学和免疫生物学实验，旨在通过直接和间接方法确定利妥昔单抗对JCV的免疫调节和病毒重新激活的作用。我们将检查利妥昔单抗治疗B细胞和T细胞的效果，以及这种治疗产生的细胞因子和趋化因子的分布。然后，我们将研究这些细胞因子对JCV感染的星形胶质细胞的影响，以确定哪些免疫调节剂负责上调JCV。通过拟议的研究，我们将阐明影响JCV活性的关键趋化因子和细胞因子，以及有效的免疫抑制治疗如何导致JCV在大脑中重新激活，从而导致致命的脱髓鞘疾病PML。

DESCRIPTION (provided by applicant): Progressive multifocal leukoencephalopathy (PML) is a fatal demyelinating disease of the central nervous system (CNS) caused by the human polyomavirus, JC virus (JCV). PML, once a rare disease of the elderly, is most frequency seen in AIDS patients and has more recently occurred in other severely immunosuppressed patients, including those on immunosuppressive therapy for the treatment of multiple sclerosis, Crohn's disease, rheumatoid arthritis, and B cell lymphomas. It is believed that immunosuppression with potent new classes of immunosuppressive agents, including the anti-CD20 molecule, rituximab, allows JC virus to replicate in patients which leads to the development of PML. We hypothesize that rituximab may indirectly lead to the development of PML by causing the release of certain cytokines or other soluble mediators which trigger JCV replication in infected astrocytes. In support of this hypothesis, our preliminary data found that conditioned media harvested from PBMCs treated with rituximab increased JCV replication in astrocytes. We have also detected upregulation of cytokines, extracellular matrix proteins, and other cellular factors by microarray analysis of JCV infected astrocytes and immunohistochemistry of PML brain tissue which further supports this hypothesis. In this study, we propose a set of cell biology and immunobiology experiments aimed at determining the effect of rituximab on immune regulation of JCV and virus reactivation through direct and indirect methods. We will examine the effect of B cell and T cell treatment with rituximab and the profile of cytokines and chemokines produced by this treatment. We will then examine the effect of these cytokines on JCV infected astrocytes to determine which immunomodulators are responsible for upregulation of JCV. Through the proposed studies, we will elucidate key chemokines and cytokines which affect JCV activity and how potent immunosuppressive therapies may cause reactivation of JCV in the brain leading to the fatal demyelinating disease, PML.