Eleouet J F, Chilmonczyk S, Besnardeau L, Laude H
Unité de Virologie et Immunologie Moléculaires, Institut National de la Recherche Agronomique, 78350 Jouy-en-Josas, France.
J Virol. 1998 Jun;72(6):4918-24. doi: 10.1128/JVI.72.6.4918-4924.1998.
In this report, we show that apoptosis (or programmed cell death) is induced in different cell lines infected with a coronavirus, the porcine transmissible gastroenteritis virus (TGEV). Kinetic analysis of internucleosomal DNA cleavage by agarose gel electrophoresis and flow cytometry or cytometric monitoring of the mitochondrial transmembrane potential showed that, for ST cells infected with TGEV, the first overt signs of apoptosis appeared from 10 to 12 h postinfection on. They preceded morphological changes characteristic of cells undergoing apoptosis, as observed by light and electron microscopy. The tripeptide pan-ICE (caspase) inhibitor N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone blocked TGEV-induced apoptosis with no effect on virus production. The thiol agent pyrrolidine dithiocarbamate inhibited apoptosis, suggesting that TGEV infection may lead to apoptosis via cellular oxidative stress. The effect of TGEV infection on activation of NF-kappaB, a transcription factor known to be activated by oxidative stress, was examined. NF-kappaB DNA binding was shown to be strongly and quickly induced by TGEV infection. However, transcription factor decoy experiments showed that NF-kappaB activation is not critical for TGEV-induced apoptosis.
在本报告中，我们表明，感染冠状病毒——猪传染性胃肠炎病毒（TGEV）的不同细胞系会诱导细胞凋亡（或程序性细胞死亡）。通过琼脂糖凝胶电泳和流式细胞术对核小体间DNA裂解进行动力学分析，或对线粒体跨膜电位进行细胞计数监测，结果显示，对于感染TGEV的ST细胞，凋亡的首个明显迹象在感染后10至12小时出现。它们先于通过光学显微镜和电子显微镜观察到的正在经历凋亡的细胞的形态学变化。三肽泛ICE（半胱天冬酶）抑制剂N-苄氧羰基-Val-Ala-Asp-氟甲基酮可阻断TGEV诱导的凋亡，且对病毒产生无影响。硫醇试剂吡咯烷二硫代氨基甲酸盐可抑制凋亡，这表明TGEV感染可能通过细胞氧化应激导致凋亡。我们检测了TGEV感染对NF-κB激活的影响，NF-κB是一种已知可被氧化应激激活的转录因子。结果显示，TGEV感染可强烈且迅速地诱导NF-κB与DNA结合。然而，转录因子诱饵实验表明，NF-κB激活对TGEV诱导的凋亡并不关键。
