HeLa细胞中泛素蛋白酶体系统对新城疫病毒复制的影响

EFFECT OF UBIQUITIN-PROTEASOME SYSTEM ON NEWCASTLE DISEASE VIRUS REPLICATION IN HELA CELLS

本文主要对细胞的泛素-蛋白酶体系统是否参与新城疫病毒(Newcastle disease virus,NDV)的复制过程进行了研究。用NDV感染HeLa细胞,对细胞样品进行Western blot实验,并检测细胞26S蛋白酶体的三种蛋白水解活性变化。同时使用多种泛素-蛋白酶体系统相关的抑制剂处理细胞并做NDV感染,测定细胞上清中病毒TCID50值,比较药物处理与DMSO处理对病毒增殖的影响。结果表明,HeLa细胞在感染NDV后,细胞内泛素化蛋白水平降低,而26S蛋白酶体的三种蛋白水解活性都显著升高;使用泛素-蛋白酶体系统抑制剂后NDV的增殖受到了明显的抑制,证明NDV在HeLa细胞内的增殖与细胞自身的泛素-蛋白酶体系统关系密切。

The objective of the present study was to examine the effect of cellular ubiquitin-proteasome system on Newcastle disease virus (NDV) replication in Hela cells. To determine whether ubiquitin-proteasome system was activated in NDV infected HeLa cells, cellular samples were taken at indicated times for Western blot and for measurement of chymotrypsin-, trypsin-and caspase-like activities. Additionally, NDV infected HeLa cells were treated with different inhibitors of ubiquitin-proteasome system and virus titers (TCID50) in culture supernatants were determined. A significant increase in 26S proteasome activity was observed after NDV infection while ubiquitinated proteins decreased. The application of inhibitors significantly reduced NDV production and delayed viral propagation. In conclusion, ubiquitin-proteasome system plays a critical role in NDV replication in HeLa cells.