NEURONAL DAMAGE RESULTING FROM LENTIVIRAL INFECTION

描述（改编自申请人的摘要）：本研究的目标 该项目是为了促进治疗的发展， 从慢病毒复制的基础研究看艾滋病的中枢神经系统并发症 在大脑中。人类免疫缺陷病毒（HIV）经常引起 严重的神经系统异常。基础 艾滋病病毒感染中的神经功能障碍仍然主要是 未知现有的证据表明，积极复制 病毒，也许在大脑中产生病毒蛋白质，间接地 导致神经元损伤和功能障碍。然而，艾滋病毒感染的 神经系统已经证明很难研究。动物模型是 因为艾滋病毒感染基本上仅限于人类。的 除了使用尸体解剖材料的研究外，人脑是无法进入的。 人类免疫细胞很容易从成年人中获得， 保持在培养物中用于研究。等效的体外研究 中枢神经系统需要人类胎儿组织， 很难获得。 在该应用中，将研究一种新的模型系统以确定 visna病毒复制对神经系统的影响， 来自绵羊（visna的天然宿主）组织培养的神经元细胞。 维斯纳病毒和HIV都是慢病毒亚科的逆转录病毒 感染大脑中相同的靶细胞。这两种病毒 在感染过程中可能会对中枢神经系统造成损害 通过共同机制。该实验室最近开发了 从胎羊中培养原代神经元的技术， 以表征培养物及其被维斯纳病毒感染。 神经元与神经胶质保持接触， 突起和突触接触在数周至数月的文化。这些 绵羊培养物可感染维斯纳病毒。该系统提供 这是一个独特的机会，研究急性和慢性影响， 慢病毒感染对来自天然宿主的神经元和神经胶质细胞的影响。 假设病毒在非神经元细胞中的复制 间接导致神经元功能障碍。具体目标是：（1） 在被维斯纳病毒感染的培养物中， 测定受感染细胞的身份和数量将被 确立了习预测是在慢性感染的文化中 相对少量的受感染巨噬细胞携带病毒， 负责对神经元的间接影响; 2）神经元如何控制 将测定CNS培养物中维斯纳病毒的复制。 初步结果表明，病毒复制是强有力的 被神经元抑制。据推测，来自神经元的信号可能 抑制病毒基因在胶质细胞中的表达，阻断复制; 3） 感染的神经胶质细胞或巨噬细胞在与 将研究神经元增强神经元损伤。的影响 感染和病毒蛋白对神经毒性和应激表达影响 蛋白质将被确定。通过这种方式， 病毒蛋白和免疫介质释放的间接影响 将区分感染的细胞。这些研究最终可能 开发新的方法来预防HIV的CNS并发症 感染

DESCRIPTION (Adapted from the applicant's abstract): The goal of this project is to contribute to the development of therapies to treat the CNS complications of AIDS through basic study of lentiviral replication in the brain. The human immunodeficiency virus (HIV) frequently causes serious neurological abnormalities in infected individuals. The basis of the neurological dysfunction seen in HIV infection remains largely unknown. The available evidence suggests that active replication of virus, and perhaps production of viral proteins in the brain, indirectly causes neuronal injury and dysfunction. However, HIV infection of the nervous system has proven difficult to investigate. Animal models are lacking because HIV infection is essentially limited to humans. The human brain is inaccessible except for studies using autopsy materials. Human immune cells are easily harvested from adult humans and can be maintained in culture for study. The equivalent in vitro studies of the central nervous system require human fetal tissue that is far more difficult to obtain. In this application, a novel model system would be studied to determine the effects of visna viral replication on the nervous system and neuronal cells in tissue culture from sheep, the natural host of visna. Visna virus and HIV are both retroviruses of the lentivirus subfamily which infect the same target cells in the brain. The two viruses probably cause damage to the central nervous system during infection through common mechanisms. This laboratory has recently developed techniques to culture primary neurons from fetal sheep, and have begun to characterize the cultures and their infection by visna virus. Neurons are maintained in contact with glia and develop extensive processes and synaptic contacts during weeks to months in culture. These sheep cultures can be infected with visna virus. This system provides the unique opportunity to study the acute and chronic effects of lentivirus infection on neurons and glia derived from the natural host. The hypothesis is that viral replication in non-neuronal cells indirectly causes neuronal dysfunction. The Specific Aims are: 1) the fate of cell types in the cultures infected by visna virus will be determined. The identity and number of infected cells will be established. The prediction is that in chronically infected cultures a relatively small number of infected macrophages harbor virus and are responsible for indirect effects on neurons; 2) how neurons control the replication of visna virus in CNS cultures will be determined. Preliminary results demonstrate that viral replication is powerfully inhibited by neurons. It is suspected that a signal from neurons may suppress virus gene expression in glia, blocking replication; 3) mechanisms by which infected glia or macrophages in co-cultures with neurons enhance neuronal injury will be investigated. The effect of infection and viral proteins on neurotoxicity and expression of stress proteins will be determined. In this way the direct toxic effects of viral proteins and the indirect effects of immune mediators released by infected cells will be distinguished. These studies may ultimately produce new approaches to preventing the CNS complications of HIV infection.