Van Den Pol A N, Vieira J, Spencer D D, Santarelli J G
Department of Neurosurgery, Yale University, New Haven, Connecticut 06520, USA.
J Comp Neurol. 2000 Nov 27;427(4):559-80. doi: 10.1002/1096-9861(20001127)427:4<559::aid-cne5>3.0.co;2-4.
Cytomegaloviruses (CMVs) are species-specific large double-stranded DNA viruses. Mouse and human CMVs have a similar morphology, similar gene sequence, and exert similar cellular effects, but the replication of the virus outside its primary host species is limited. This may confer upon CMV certain advantages for expression of foreign genes or cellular labels in brain cells of nonhost species. We examined the ability of recombinant mouse (m)CMV expressing green fluorescent protein (GFP) to serve as a vector for transgene expression in developing neurons and glia outside the normal host species. For comparative purposes, 11 species were examined. Mouse CMV reporter gene expression was particularly strong in the developing brain of its normal host species, mouse, where it replicated in cultures and brain slices, leading to cell death. All mammalian species tested (human, rat, gerbil, hamster, mouse) showed reporter gene expression after mCMV infection. High levels of mCMV infection were also found in chicken central nervous system cells in vitro, and a low level of mCMV expression was found after an initial delay in turtle neurons and glia. No mCMV reporter gene expression was found in frog cells or aplysia neurons or glia or in drosophila or fungal cells. Infection of nonmouse neurons by low concentrations of mCMV led to strong expression of GFP in dendrites and axons with normal morphology. Despite the lack of replication, high doses of mCMV induced morphologic changes in neurons and glia from hamster and rat brain slices, leading to cells rounding up, and to the formation of giant cells consisting of an aggregate of many cells fused together into a syncytium. In contrast, in human hippocampal slices, GFP-expressing cells infected with mCMV had a relatively normal appearance 12 days after inoculation. To determine whether a CMV from another species could serve as a vector for gene transfer, a recombinant human CMV-expressing GFP was used for transgene expression in rat brain cells in vitro. Cytomegaloviruses thus have potential as useful vectors for gene transfer and labeling central nervous system cells, with the actions of CMV being dependent on a number of factors.
巨细胞病毒（CMV）是种属特异性的大型双链DNA病毒。小鼠和人类巨细胞病毒具有相似的形态、相似的基因序列，并产生相似的细胞效应，但该病毒在其主要宿主物种之外的复制受到限制。这可能赋予巨细胞病毒在非宿主物种的脑细胞中表达外源基因或细胞标记物某些优势。我们研究了表达绿色荧光蛋白（GFP）的重组小鼠（m）CMV作为正常宿主物种之外发育中的神经元和神经胶质中转基因表达载体的能力。为作比较，研究了11个物种。小鼠巨细胞病毒报告基因在其正常宿主物种小鼠发育中的大脑中表达特别强烈，在培养物和脑片中进行复制，导致细胞死亡。所有测试的哺乳动物物种（人类、大鼠、沙鼠、仓鼠、小鼠）在感染mCMV后均显示报告基因表达。在体外鸡中枢神经系统细胞中也发现了高水平的mCMV感染，在海龟神经元和神经胶质细胞最初延迟后发现了低水平的mCMV表达。在青蛙细胞、海兔神经元或神经胶质细胞、果蝇或真菌细胞中未发现mCMV报告基因表达。低浓度的mCMV感染非小鼠神经元导致具有正常形态的树突和轴突中GFP强烈表达。尽管缺乏复制，但高剂量的mCMV诱导仓鼠和大鼠脑片神经元和神经胶质细胞发生形态变化，导致细胞变圆，并形成由许多细胞聚集融合成一个多核体的巨细胞。相比之下，在人海马切片中，接种mCMV 12天后，感染的表达GFP的细胞外观相对正常。为了确定来自另一个物种的CMV是否可以作为基因转移载体，使用表达GFP的重组人CMV在体外大鼠脑细胞中进行转基因表达。因此，巨细胞病毒有潜力成为用于基因转移和标记中枢神经系统细胞的有用载体，CMV的作用取决于多种因素。
