中华医学杂志（英文版）2002，Vol.115Issue(9)：1324-1327,4.
KN73细胞持续感染乙脑病毒的模型中变异株性状及E蛋白表达
Characterization and E protein expression of mutant strains during persistent infection of KN73 cells with Japanese encephalitis virus
摘要
Abstract
Objective To study the character of mutants originating from Japanese encephalitis viruses and the relationship between the characterization of mutant strains and E protein expression.Methods Persistent infection was established with standard strains of Japanese encephalitis viruse, known as parental viruse, in a human hepatoma cell line, KN73. Cells were subcultured weekly using trypsinization techniques. Cell-associated viruses of persistently infected cells were collected by a freeze and thaw method. Virus titers were examined by plaque method using baby hamster kidney (BHK) cells. Indirect immunofluorescence assays were used to examine E and NS3 protein antigens. Wester*# n blot analysis was used to test expression of E and NS3 proteins. Results In the early phase (24-36 h) post-infection, virus titer in culture fluid from KN73 cells infected with parental viruses were 106 PFU/ml. They were 103-4 PFU/ml in the late phase (3 years) post-infection. The titer of cell-associated viruse was 102-3 PFU/ml. A virus super-infection assay found that virus titers in culture fluid from persistently infected KN73 cells acutely super- infected with parental viruses were much lower than that of culture fluids in acutely infected normal KN73 at the same phase. Indirect immunoflurescence assay revealed that the quantity of viral antigens in persistently infected KN73 cells was lower than that in acutely infected KN73 cells with parental viruses. Western blot analyses indicated that the molecular weights of E and NS3 proteins were 53 kD and 73 kD, respectively. Expression of NS3 protein in persistently infected KN73 cells was stable but expression of E protein was markedly suppressed. Conclusions The virulence and reproduction of viruses obtained from persistently infected KN73 cells, which have some features of DI viruses and were involved in persistent infection, was lower than that of parental viruses. These mutants may have be related to the decrease in E protein expression.关键词
流行性乙型脑炎 持续感染 E蛋白表达Key words
apanese encephalitis virus/persistent infection/E protein expression分类
医药卫生引用本文复制引用
冯国和,竹上勉,赵桂珍..KN73细胞持续感染乙脑病毒的模型中变异株性状及E蛋白表达[J].中华医学杂志（英文版）,2002,115(9):1324-1327,4.基金项目
This work was supported by the Tropical Deptartment f General Medical Institute,Kanazawa Medical University,Japan. （）
