Mizutani Tetsuya, Fukushi Shuetsu, Ishii Koji, Sasaki Yuko, Kenri Tsuyoshi, Saijo Masayuki, Kanaji Yumi, Shirota Kinji, Kurane Ichiro, Morikawa Shigeru
Department of Virology 1, National Institute of Infectious Diseases, Musashimurayama, Tokyo, Japan.
Biochem Biophys Res Commun. 2006 Aug 18;347(1):261-5. doi: 10.1016/j.bbrc.2006.06.086. Epub 2006 Jun 22.
Previously, we reported the establishment of cells with persistent SARS-CoV infection after apoptotic events and showed that both JNK and PI3K/Akt signaling pathways are important for persistence by treatment with inhibitors at the early stages of SARS-CoV infection. However, the mechanisms of establishment of persistent infection are still unclear. In this study, we investigated which signaling pathways play important roles in escape from apoptosis in cells infected with SARS-CoV. In persistently infected cells at 50h.p.i., PI3K/Akt, JNK, p38 MAPK and Bcl-2 were phosphorylated and the protein levels of Bcl-2 and Bcl-xL were increased. When surviving cells were treated with the JNK-specific inhibitor, SP600125, at 50h.p.i., all cells died, suggesting that the JNK signaling pathway is necessary for maintenance of persistently infected cells. Among the signaling pathways in persistently infected cells, Akt and JNK were phosphorylated in SARS-CoV-nucleocapsid (N) protein-expressing Vero E6 cells using vaccinia viral vector (DIs), strongly suggesting that N protein-induced phosphorylation of Akt and JNK are necessary to establish persistence. These results indicated that at least four proteins, Akt, JNK, Bcl-2 and Bcl-xL, are necessary for survival of persistently SARS-CoV-infected cells.
此前，我们报道了在凋亡事件后建立的持续感染严重急性呼吸综合征冠状病毒（SARS-CoV）的细胞，并表明在SARS-CoV感染早期用抑制剂处理时，JNK和PI3K/Akt信号通路对病毒持续存在都很重要。然而，持续感染的建立机制仍不清楚。在本研究中，我们调查了哪些信号通路在SARS-CoV感染的细胞逃避凋亡中起重要作用。在感染后50小时的持续感染细胞中，PI3K/Akt、JNK、p38丝裂原活化蛋白激酶（MAPK）和Bcl-2被磷酸化，并且Bcl-2和Bcl-xL的蛋白水平增加。当在感染后50小时用JNK特异性抑制剂SP600125处理存活细胞时，所有细胞均死亡，这表明JNK信号通路对于维持持续感染的细胞是必需的。在持续感染细胞的信号通路中，使用痘苗病毒载体（DIs）在表达SARS-CoV核衣壳（N）蛋白的Vero E6细胞中，Akt和JNK被磷酸化，强烈表明N蛋白诱导的Akt和JNK磷酸化对于建立持续性是必需的。这些结果表明，至少四种蛋白，Akt、JNK、Bcl-2和Bcl-xL，对于持续感染SARS-CoV的细胞的存活是必需的。
