Function and mechanisms of reovirus-induced apoptosis

描述（由申请人提供）：嗜神经病毒是儿童和成人发病和死亡的重要原因。本建议的中心目标是加强对病毒损伤中枢神经系统（CNS）机制的理解。哺乳动物呼肠孤病毒为研究嗜神经病毒与宿主的相互作用提供了高度可处理的模型。呼肠孤病毒对幼龄哺乳动物具有嗜神经性和高毒性。像其他嗜神经病毒一样，呼肠孤病毒在小鼠中枢神经系统中引起细胞凋亡，导致致命性脑炎。然而，目前尚不清楚这种促凋亡能力是一种有利于病毒适应性的特性，还是宿主免疫防御的无意影响，或者两者兼而有之。呼肠孤病毒诱导细胞凋亡的一个重要宿主决定因素是先天免疫转录因子NF-:B。呼肠孤病毒神经病理在NF-:B缺乏的小鼠中减弱，但NF-:B介导的呼肠孤病毒神经损伤机制仍未明确。提出了三个特定的目的来阐明呼肠孤病毒感染中细胞凋亡的作用，并加强对介导呼肠孤病毒诱导的中枢神经系统细胞凋亡的细胞机制的理解。在特异性目的1中，细胞凋亡在呼肠孤病毒感染中的作用将被定义。具有调节凋亡能力的单氨基酸改变的等基因突变病毒将被设计和比较其复制、传播、引起组织损伤和在宿主之间传播的能力。在特异性目的2中，将确定细胞类型特异性NF-:B信号在呼肠孤病毒诱导的脑炎中的作用。产生神经元和造血特异性NF-:B缺陷小鼠并感染呼肠孤病毒。将评估这些动物的病毒复制、传播、趋向性和组织损伤。在特异性目标3中，NF-: b调节的呼肠孤病毒诱导的中枢神经系统凋亡介质将使用体内成像质谱方法进行鉴定。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。这些研究将为中枢神经系统中病毒性疾病的机制提供重要的见解，并可能导致新的治疗干预策略的发展。

DESCRIPTION (provided by applicant): 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-:B. Reovirus neuropathology is attenuated in mice deficient in NF-:B, but the mechanism of NF-:B-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-:B signaling to reovirus-induced encephalitis will be determined. Neuron- and hematopoietic-specific NF-:B- 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-:B-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. PUBLIC HEALTH RELEVANCE: Studies described in this proposal will define the role of apoptosis in reovirus infection and contribute new insights into mechanisms of reovirus neuropathology. This research will enhance a basic understanding of mechanisms underlying viral disease in the CNS. In turn, this knowledge may foster development of new antiviral agents that act by blocking apoptosis.