NEURAL CELLS PERSISTENTLY INFECTED WITH SV40, BKV OR JCV

该提案的目的是促进我们对巴多空病毒的了解 一般持续感染，并阐明这些过程， 可能是人类慢病毒感染中乳多空病毒持续存在和发病机制的基础。 病毒性疾病、进行性多灶性白质脑病（PML）。 因为 这种神经退行性疾病是唯一一种 乳多空病毒显然与此有关，我们也试图确定那些 可能使中枢神经系统易受巴多空病毒感染的因素 或者更有可能是慢性疾病。 为此，我们将评估猿猴病毒40的基本参数 （SV4Q）、BK病毒和JC病毒（PML的主要病原体） 在人神经母细胞瘤培养物中建立的持续性感染， 胶质母细胞瘤细胞系，在人少突胶质细胞瘤的外植体中，以及在人成胶质细胞瘤细胞系中， 非神经来源的细胞培养物。 我们将决定 产生病毒或仅支持有限病毒基因的细胞 表达，或含有完全潜伏的病毒基因组。 我们将 评估病毒复制和细胞增殖之间的时间关系， 杀人 我们将确定病毒基因组的状态（例如， 整合与游离，缺陷与非缺陷）， 克隆分离物，并评估这些分离物之间是否存在关系， 状态和生产性感染重新激活的概率。 我们 将分析可能出现的病毒变体，特别是在 调节生产性感染的能力。 我们将评估 这些细胞因子可能起着调节感染的作用， 确定这些因素是否与患者的生理状态有关， 细胞或其分化水平。 为了进一步了解PML疾病过程，我们将确定 如果持续感染导致特定的损伤， 由神经元样和神经胶质样细胞培养物表达的功能。 要检查的专门功能包括以下酶的活性： 神经递质代谢，神经递质受体功能， 电生理活性，以及神经胶质细胞表达 促进和维持功能能力的外在影响 神经元细胞。

The goal of this proposal is to advance our understanding of papovaviral persistent infection in general and, to elucidate those processes which might underlie papovaviral persistence and pathogenesis in the human slow virus disease, progressive multifocal leukoencephalopathy (PML). Because this neurodegenerative disease is the only human illness in which papovaviruses are clearly implicated, we also seek to identify those factors which might predispose the central nervous system to papovaviral persistence or, more likely, to chronic disease. Toward these ends we will evaluate basic parameters of simian virus 40 (SV4Q), BK virus, and JC virus (the primary etiologic agent of PML) persistent infections established in cultures of human neuroblastoma and glioblastoma cell lines, in explants of human oligodendrogliomas, and in cell cultures of non-neural origin. We will determine the proportion of cells which either produce virus, or which support only limited viral gene expression, or which contain completely latent viral genomes. We will assess the temporal relationship between viral replication and cell killing. We will determine the states of the viral genomes (e.g. integrated versus free, defective versus nondefective) in latently infected clonal isolates and assess whether there is a relationship between those states and the probability of reactivation of the productive infection. We will analyze viral variants which might emerge, particularly with respect to their capacities to modulate the productive infection. We will evaluate cellular factors which might act to regulate the infection and we will determine whether those factors are related to the physiological state of the cells or to their level of differentiation. To advance our understanding of the PML disease process we will determine if persistent infection leads to specific impairment of the specialized functions expressed by the neuronal-like and glial-like cell cultures. Specialized functions to be examined include enzyme activities of neurotransmitter metabolism, neurotransmitter receptor functions, electrophysiological activity, and the expression by glial cells of extrinsic influences which promote and maintain the functional competence of neuronal cells.