诱导凋亡:脊髓灰质炎病毒致细胞病变的机制

APOPTOSIS:A MECHANISM FOR POLIOVIRUS TO INDUCE CYTOPATHIC EFFECTS

用脊髓灰质炎病毒(Poliovirus)减毒活疫苗株(中Ⅲ-2)感染人二倍体胚肺成纤维细胞株(KMB17)后,细胞形态变化分为两个阶段:第一阶段是致CPE过程,导致形态学上特有的细胞圆缩、体积缩小等CPE特征,经光学显微镜、荧光显微镜、细胞流式仪、电子显微镜、DNA凝胶电泳分析,证明该疫苗株诱导的细胞病理改变具典型的凋亡特征;细胞圆缩、细胞核浓缩破裂、核染色质凝缩后分布于核膜边缘、绝大部分细胞出现在凋亡区域、DNA断裂。表明脊髓灰质炎病毒诱导的CPE本质是一个诱导细胞凋亡过程;第二阶段是Poliovirus诱导细胞坏死。进一步提示有可能通过抑制细胞凋亡提高脊髓灰质炎减毒活疫苗的产量。

In order to study the relationship between cytopathic effects and apoptosis, we used type- I live attenuated Po-liovirus vaccine (Strain:Zhong 1-2) to infect the human diploid fibroblast (KMB17) in culture. There were two kinds of different morphological changes occurred during the whole infection by Poliovirus. At the first stage,the typical CPE appeared,the confluent KMB17 fibroblast rapidly shrank and disintegrated 24 hours after Poliovirus infection, through the analysis of light microscopy,fluorescent light microscope,electronic microscopy,flow cytometer and DNA eletrophoresis, it were demonstrated that the CPE cells showed the typical apoptotic charateristics of cellular shrinkage,nuclear shrinkage,crescent chromatin around nuclear membrane,DNA breakage (although not typical laden type). At the second stage,the characteristics of secondary necrosis appeared,cellular lysis and chromatin breakdown were detected by electronic microscopy and flow cytometer. In conclusion,we demonstrated that Poliovirus causes both apoptosis and secondary necrosis in cell culture, the CPE caused by Poliovirus is actually the apoptosis in human diploid fibroblast (KMB17).