Function and mechanisms of reovirus-induced apoptosis

项目总结/摘要 嗜神经病毒是儿童和成人发病和死亡的重要原因。该提案的中心目标是加强对病毒损伤中枢神经系统（CNS）的机制的理解。哺乳动物呼肠孤病毒是研究嗜神经病毒-宿主相互作用的高度易处理的模型。呼肠孤病毒是嗜神经性的，在幼年哺乳动物中具有高毒性。与其他嗜神经病毒一样，呼肠孤病毒引起小鼠CNS细胞凋亡，导致致命性脑炎。然而，尚不清楚这种促凋亡能力是否是有益于病毒适应性的性状，宿主免疫防御的无意影响，或两者的组合。呼肠孤病毒诱导的细胞凋亡的一个重要的宿主决定因子是先天免疫转录因子NF-κ B。呼肠孤病毒神经病理学在NF-kB缺陷的小鼠中减弱，但NF-kB介导的呼肠孤病毒神经损伤的机制在很大程度上仍不明确。提出了三个具体的目标，以阐明细胞凋亡在呼肠孤病毒感染的作用，并加强对细胞机制介导的中枢神经系统呼肠孤病毒诱导的细胞凋亡的理解。在具体目标1中，将定义细胞凋亡在呼肠孤病毒感染中的作用。将对具有调节凋亡能力的单个氨基酸变化的同基因突变病毒进行工程改造，并比较其复制、传播、引起组织损伤和在宿主之间传播的能力。在具体目标2中，将确定细胞类型特异性NF-κ B信号传导对呼肠孤病毒诱导的脑炎的贡献。将产生神经元特异性和造血特异性NF-kB缺陷小鼠并用呼肠孤病毒感染。将评估这些动物中的病毒复制、传播、嗜性和组织损伤。在特定目标3中，将使用体内成像质谱法鉴定CNS中呼肠孤病毒诱导的细胞凋亡的NF-κ B调节介质。候选蛋白将使用呼肠孤病毒细胞损伤和神经病理学模型进行分析。这些研究将为CNS病毒性疾病的机制提供重要的见解，并可能导致开发新的治疗干预策略。

PROJECT SUMMARY/ABSTRACT Neurotropic viruses are a significant cause of morbidity and mortality in children and adults. The central objective of this proposal is to enhance an understanding of mechanisms by which viruses injure the central nervous system (CNS). Mammalian reoviruses serve as highly tractable models for studies of neurotropic virus-host interactions. Reoviruses are neurotropic and highly virulent in young mammals. Like other neurotropic viruses, reovirus causes apoptosis in the murine CNS, leading to fatal encephalitis. However, it is not known if this pro-apoptotic capacity is a trait that benefits viral fitness, an inadvertent effect of host immune defense, or a combination of both. An important host determinant of reovirus-induced apoptosis is the innate immune transcription factor NF-kB. Reovirus neuropathology is attenuated in mice deficient in NF-kB, but the mechanism of NF-kB-mediated reovirus neural injury remains largely undefined. Three specific aims are proposed to elucidate the role of apoptosis in reovirus infection and enhance an understanding of cellular mechanisms mediating reovirus-induced apoptosis in the CNS. In Specific Aim 1, the role of apoptosis in reovirus infection will be defined. Isogenic mutant viruses with single amino acid changes that modulate apoptotic capacity will be engineered and compared for the capacity to replicate, disseminate, cause tissue injury, and transmit between hosts. In Specific Aim 2, the contribution of cell type-specific NF-kB signaling to reovirus-induced encephalitis will be determined. Neuron- and hematopoietic-specific NF-kB-deficient mice will be generated and infected with reovirus. Viral replication, dissemination, tropism, and tissue injury in these animals will be assessed. In Specific Aim 3, NF-kB-regulated mediators of reovirus-induced apoptosis in the CNS will be identified using an in vivo imaging mass spectrometry approach. Candidate proteins will be analyzed using models of reovirus cell injury and neuropathology. These studies will provide important insights into mechanisms of viral disease in the CNS and may lead to the development of novel strategies for therapeutic intervention.