NEURAL CELLS PERSISTENTLY INFECTED WITH SV40, BKV OR JCV

这项建议的目的是增进我们对罂粟花病毒的了解 一般的持续性感染，并阐明哪些过程 可能是乳头状病毒在人类慢性期持续和致病的基础 病毒病，进行性多灶性白质脑病(PML)。因为 这种神经退行性疾病是人类唯一一种 显然与乳头病毒有牵连，我们也试图确定 可能使中枢神经系统感染乳头状病毒的因素 坚持，或者，更有可能是慢性病。 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) 在人神经母细胞瘤和神经母细胞瘤培养中建立的持续性感染 人少突胶质瘤外植体中的胶质母细胞瘤细胞系，以及 非神经来源的细胞培养。我们将确定以下比例： 要么产生病毒，要么只支持有限病毒基因的细胞 表达，或包含完全潜伏的病毒基因组。我们会 评估病毒复制和细胞之间的时间关系 杀戮。我们将确定病毒基因组的状态(例如 集成与免费、缺陷与非缺陷)在潜伏感染中 克隆分离株，并评估它们之间是否存在关系 状态和生产性感染重新激活的可能性。我们 将分析可能出现的病毒变异，特别是尊重 它们调节生殖性感染的能力。我们将评估 可能起到调节感染作用的细胞因子，我们会 确定这些因素是否与患者的生理状态有关 细胞或它们的分化水平。 为了促进我们对PML疾病过程的理解，我们将确定 如果持续感染导致特定的特殊功能障碍 神经元样和神经胶质样细胞培养所表达的功能。 要检查的特殊功能包括酶活性 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.