MOLECULAR PATHOGENESIS OF JC VIRUS & PROGRESSIVE MULTIFOCAL LEUKOENCEPHALOPATHY

JCV~诱导的渐进性多焦研究 白质脑病(PML)是在临床标本上进行的， 组织培养和宿主细胞的生化分析。JCV DNA是 90%以上的PML患者外周血淋巴细胞中检测到 采用聚合酶链式反应进行分析。这些患者中的许多人都以艾滋病为潜在的 免疫性疾病。在没有PML的HIV~1血清阳性个体中，更多 超过50%的人被发现在他们的外周有JCV 淋巴细胞。这后一组人将面临在 未来。三年前在骨髓和肾组织中发现JCV DNA 在Wiskott~Aldrich综合征患者出现PML之前， 在骨髓和大脑样本中发现了后者，当时 验尸报告。后一种情况表明JCV可以在细胞中潜伏 在骨髓中，此外在外周血中发现JCV 淋巴细胞，提示JCV可以通过一种 输血途径。基因控制下的表达载体 Mad~1或“Brain”型毒株Mad~8的调控区是 被构建为检查什么组织和细胞类型可以影响 JCV基因的表达。氯霉素乙酰转移酶和β- 半乳糖苷酶表达载体用于转基因研究 回答组织特异性和细胞特异性表达的问题 JCV的。人胎儿核蛋白的生化分析 对大脑和人类B细胞进行了研究，以确定相似的蛋白质 参与了JCV基因在这些组织中的表达。核子 这两种人类细胞系的蛋白质都能够特异性地 与JCV调控中的相同核苷酸序列相互作用 区域。其中一种蛋白质因子被鉴定为核因子 因子~1(NF~1)蛋白和c~jun样因子。在 JCV的调控区，有几个NF~1蛋白结合 网站。C~jun结合位点要么相邻，要么重叠 NF~1结合位点位于调控区。一种类似的 推测的核因子~1和激活蛋白结合位点的相关性是 在大脑中表达的许多其他基因中都有发现。这些结果 提示人类脑细胞和B细胞可能含有类似的因子 它可以调节JCV在这些组织中的表达。

Investigations of JCV~induced progressive multifocal leukoencephalopathy (PML) are being carried out on clinical specimens, in tissue culture, and biochemical analysis of host cells. JCV DNA was detected in peripheral lymphocytes in more than 90% of PML patients using PCR analysis. Many of these patients had AIDS as the underlying immune disorder. In HIV~1 seropositive individuals without PML, more than 50% of the individuals were found to have JCV in their peripheral lymphocytes. This later group would be at risk to develop PML in the future. JCV DNA was found in bone marrow and kidney tissue three years prior to the onset of PML in a patient with Wiskott~Aldrich syndrome, and latter found in bone marrow and brain samples taken at the time of autopsy. This latter case suggests that JCV can be latent in cells in bone marrow, and in addition, with the finding of JCV in peripheral lymphocytes, suggest that JCV could be spread to the CNS by a hematogenous route. Expression vectors under the control of the prototype Mad~1 or "brain" type strain Mad~8 regulatory region are being constructed to examine what tissue and cell type can influence JCV gene expression. Both chloramphenicol acetlytransferase and beta- galactosidase expression vectors are used in transfection studies to answer the question of tissue specific and cell specific expression of JCV. Biochemical analysis of nuclear proteins from human fetal brain and human B cells were studied to determine if similar proteins were involved in JCV gene expression in these tissues. Nuclear proteins from both these human cell lines were able to specifically interact with identical nucleotide sequences in the JCV regulatory region. One of these protein factors was identified as a nuclear factor~1 (NF~1) protein and the other a c~Jun like factor. Within the regulatory region of JCV, there were several NF~1 protein binding sites. The c~Jun binding sites were either adjacent or overlapped all the NF~1 binding sites located in the regulatory region. A similar association of putative NF~1 and activator protein binding sites was found in many other genes expressed in the brain. These results suggest that human brain cells and B cells may contain similar factors which can regulate the expression of JCV in these tissues.