Sanfilippo Christine M, Chirimuuta Fungai N W, Blaho John A
Department of Microbiology, Mount Sinai School of Medicine, New York, New York 10029, USA.
J Virol. 2004 Jan;78(1):224-39. doi: 10.1128/jvi.78.1.224-239.2004.
Wild-type herpes simplex virus type 1 (HSV-1) induces apoptosis in human epithelial HEp-2 cells, but infected cell proteins produced later in infection block the process from killing the cells. Thus, HSV-1 infection in the presence of the translational inhibitor cycloheximide (CHX) results in apoptosis. Our specific goal was to gain insight as to the viral feature(s) responsible for triggering apoptosis during HSV-1 infection. We now report the following. (i) No viral protein synthesis or death factor processing was detected after infection with HSV-1(HFEMtsB7) at 39.5 degrees C; this mutant virus does not inject its virion DNA into the nucleus at this nonpermissive temperature. (ii) No death factor processing or apoptotic morphological changes were detected following infection with UV-irradiated, replication-defective viruses possessing transcriptionally active incoming VP16. (iii) Addition of the transcriptional inhibitor actinomycin D prevented death factor processing upon infection with the apoptotic, ICP27-deletion virus HSV-1(vBSDelta27). (iv) Apoptotic morphologies and death factor processing were not observed following infection with HSV-1(d109), a green fluorescent protein-expressing recombinant virus possessing deletions of all five immediate-early (IE) (or alpha) genes. (v) Finally, complete death factor processing was observed upon infection with the VP16 transactivation domain-mutant HSV-1(V422) in the presence of CHX. Based on these findings, we conclude that (vi) the expression of HSV-1 alpha/IE genes is required for the viral induction of apoptosis and (vii) the transactivation activity of VP16 is not necessary for this induction.
野生型单纯疱疹病毒1型（HSV-1）可诱导人上皮HEp-2细胞发生凋亡，但感染后期产生的感染细胞蛋白会阻断这一导致细胞死亡的过程。因此，在存在翻译抑制剂环己酰亚胺（CHX）的情况下，HSV-1感染会导致细胞凋亡。我们的具体目标是深入了解HSV-1感染期间负责触发细胞凋亡的病毒特征。我们现在报告以下内容。（i）在39.5摄氏度下用HSV-1（HFEMtsB7）感染后，未检测到病毒蛋白合成或死亡因子加工；这种突变病毒在这个非允许温度下不会将其病毒体DNA注入细胞核。（ii）用具有转录活性的传入VP16的紫外线照射、复制缺陷型病毒感染后，未检测到死亡因子加工或凋亡形态变化。（iii）添加转录抑制剂放线菌素D可防止在用凋亡性ICP27缺失病毒HSV-1（vBSDelta27）感染时的死亡因子加工。（iv）用HSV-1（d109）感染后未观察到凋亡形态和死亡因子加工，HSV-1（d109）是一种表达绿色荧光蛋白的重组病毒，缺失所有五个立即早期（IE）（或α）基因。（v）最后，在存在CHX的情况下，用VP16反式激活结构域突变体HSV-1（V422）感染后观察到完全的死亡因子加工。基于这些发现，我们得出结论：（vi）HSV-1α/IE基因的表达是病毒诱导细胞凋亡所必需的，（vii）VP16的反式激活活性对于这种诱导不是必需的。
