Chen W J, Chen S L, Fang A H
Department of Parasitology, Kaohsiung Medical College, Taiwan.
Intervirology. 1994;37(1):25-30. doi: 10.1159/000150352.
A C6/36 cell culture persistently infected by dengue 2 virus was established and retained for over 20 weeks. No CPE was observed at any stage of infection. However, some giant cells up to 2- or 3-fold the diameter of normal cells appeared in the established culture. Extracellular virus titers fluctuated with a periodic tendency while the antigen level remained constant, suggesting some viral particles evolved into noninfectious defective interfering particles. Plaque size tended to change during the passage of cultures. The passage 8 virus mainly produced plaques relatively smaller than those produced by the passage 1 virus. Nevertheless, the plaque sizes produced by the passages 18 virus were somewhat mosaic. A temperature-sensitive mutant was detected in the virus released from passages 8 and 18. In addition, passages 8 and 18 produced the lowest virus titers. When persistently infected viruses were grown in Vero cells at 37 degrees, at passage 1 there was a high titer which decreased 5 days postinoculation, whereas at passages 8 and 18 titers were undetectable until 4 days postinoculation. It seems that dengue 2 virus persistently infected in C6/36 cells could have been genetically altered. This will be tested by nucleic acid analysis of the viruses.
建立了一种被登革2型病毒持续感染的C6/36细胞培养物，并保留了20周以上。在感染的任何阶段均未观察到细胞病变效应（CPE）。然而，在已建立的培养物中出现了一些直径达正常细胞2至3倍的巨型细胞。细胞外病毒滴度呈周期性波动，而抗原水平保持恒定，这表明一些病毒颗粒演变成了无感染性的缺陷干扰颗粒。在培养物传代过程中，蚀斑大小趋于变化。第8代病毒产生的蚀斑主要比第1代病毒产生的蚀斑相对更小。然而，第18代病毒产生的蚀斑大小有些参差不齐。在第8代和第18代释放的病毒中检测到一个温度敏感突变体。此外，第8代和第18代产生的病毒滴度最低。当持续感染的病毒在37摄氏度的Vero细胞中培养时，第1代接种后有高滴度，接种5天后滴度下降，而第8代和第18代直到接种后4天才检测到滴度。似乎在C6/36细胞中持续感染的登革2型病毒可能发生了基因改变。这将通过对病毒的核酸分析来进行验证。
