Knebel D, Doerfler W
Institute of Genetics, University of Cologne, West Germany.
Virus Res. 1987 Nov;8(4):317-26. doi: 10.1016/0168-1702(87)90004-9.
The insect baculovirus Autographa californica nuclear polyhedrosis virus (AcNPV) replicates in insect cell lines in culture. In mammalian cells, however, the virus cannot be propagated. AcNPV DNA does not replicate or persist and is not transcribed in mammalian cells (Tjia et al., 1983). In insect cells productively infected with AcNPV, at least two major late viral gene products have been recognized, the polyhedrin, which makes up the bulk of the polyhedral inclusion bodies in infected cell nuclei, and a 10,000 Da protein (p10) of unknown function. The p10 promoter has been fused to the prokaryotic gene for chloramphenicol acetyltransferase (CAT) as a reporter gene (Knebel et al., 1985). Activity of this construct can be elicited in AcNPV-infected insect cells but not in uninfected insect cells or in mammalian cells. Presumably, the late p10 promoter requires other AcNPV gene products for activity. When the pAcp10-CAT construct is transfected into BHK21 hamster cells at about 18 h after infection with human adenovirus type 5 (Ad5), the insect AcNPV promoter is transactivated in cells of the heterologous mammalian species. The results of S1 protection analyses on the RNA from Ad5-infected and pAcp10-CAT transfected cells reveal that the p10 promoter is used for initiation of transcription. Similarly, the p10 insect virus promoter is activated in BHK21 hamster cells cotransfected with the HindIII-G fragment of adenovirus type 2 (Ad2) DNA which contains the E1A and parts of the E1B region in the left terminal 7.8% of the Ad2 genome. Moreover, in human 293 cells or in BHK297-C131 hamster cells, which both carry and constitutively express the E1 region of Ad5 DNA, the pAcp10-CAT construct is also expressed, and similarly in HE7 hamster cells which carry appreciable portions of the Ad2 genome (Klimkait and Doerfler, 1985). It is concluded that adenovirus functions are capable of transactivating a heterologous insect virus promoter in mammalian cells.
昆虫杆状病毒苜蓿银纹夜蛾核型多角体病毒（AcNPV）可在培养的昆虫细胞系中复制。然而，在哺乳动物细胞中，该病毒无法增殖。AcNPV DNA在哺乳动物细胞中不复制、不持续存在且不转录（Tjia等人，1983年）。在被AcNPV有效感染的昆虫细胞中，至少已识别出两种主要的晚期病毒基因产物，一种是多角体蛋白，它构成了被感染细胞核中多面体包涵体的大部分，另一种是功能未知的10000道尔顿蛋白（p10）。p10启动子已与氯霉素乙酰转移酶（CAT）的原核基因融合作为报告基因（Knebel等人，1985年）。该构建体的活性可在被AcNPV感染的昆虫细胞中引发，但在未感染的昆虫细胞或哺乳动物细胞中则不会引发。据推测，晚期p10启动子的活性需要其他AcNPV基因产物。当pAcp10-CAT构建体在感染人5型腺病毒（Ad5）约18小时后转染到BHK21仓鼠细胞中时，昆虫AcNPV启动子在异源哺乳动物细胞中被反式激活。对来自Ad5感染和pAcp10-CAT转染细胞的RNA进行S1保护分析的结果表明，p10启动子用于启动转录。同样，p10昆虫病毒启动子在与2型腺病毒（Ad2）DNA的HindIII-G片段共转染的BHK21仓鼠细胞中被激活，该片段包含Ad2基因组左末端7.8%的E1A和部分E1B区域。此外，在携带并组成性表达Ad5 DNA的E1区域的人293细胞或BHK297-C131仓鼠细胞中，pAcp10-CAT构建体也会表达，在携带相当一部分Ad2基因组的HE7仓鼠细胞中也是如此（Klimkait和Doerfler，1985年）。得出的结论是，腺病毒功能能够在哺乳动物细胞中转激活异源昆虫病毒启动子。
