Kajita M, Katayama H, Murata T, Kai C, Hori M, Ozaki H
Department of Veterinary Pharmacology, Graduate School of Agriculture and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
J Vet Med B Infect Dis Vet Public Health. 2006 Aug;53(6):273-7. doi: 10.1111/j.1439-0450.2006.00963.x.
We investigated the signal-transduction pathway of canine distemper virus-Onderstepoort (CDV-Ond) vaccine strain-mediated apoptosis in Vero cells. Canine distemper virus-Onderstepoort at a multiplicity of infection (MOI) of 0.1 induced DNA fragmentation 48 h after infection. Immunofluorescence staining revealed that 57% +/- 4% of the CDV-N-protein-positive cells were terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-positive, and all TUNEL-positive cells were CDV-N-protein-positive, indicating that CDV-Ond induced apoptosis only in the infected cells. We also found that CDV-Ond infection induced activation of caspase-3 and caspase-8. In the semi-quantitative reverse transcription-polymerase chain reaction assay for apoptosis-related genes, the expression of mRNA of the death receptor, Fas, was also increased in CDV-Ond-infected cells. In contrast, the expressions of Bcl-2 and Bax, regulators for intrinsic apoptotic signaling through the mitochondria, did not change. These results suggest that CDV-Ond induced apoptosis by activating caspase-3, possibly through caspase-8 signaling rather than through p53/Bax-mediated, mitochondrial signaling in the infected cells.
我们研究了犬瘟热病毒-翁德斯特普特（CDV-Ond）疫苗株介导的Vero细胞凋亡的信号转导途径。感染复数（MOI）为0.1的犬瘟热病毒-翁德斯特普特在感染后48小时诱导DNA片段化。免疫荧光染色显示，57%±4%的CDV-N蛋白阳性细胞为末端脱氧核苷酸转移酶介导的dUTP缺口末端标记（TUNEL）阳性，且所有TUNEL阳性细胞均为CDV-N蛋白阳性，表明CDV-Ond仅在感染细胞中诱导凋亡。我们还发现CDV-Ond感染诱导了caspase-3和caspase-8的激活。在凋亡相关基因的半定量逆转录-聚合酶链反应分析中，死亡受体Fas的mRNA表达在CDV-Ond感染的细胞中也增加。相比之下，通过线粒体进行内在凋亡信号调节的Bcl-2和Bax的表达没有变化。这些结果表明，CDV-Ond可能通过caspase-8信号而非p53/Bax介导的线粒体信号激活caspase-3，从而在感染细胞中诱导凋亡。
