H5N1 Avian Influenza Virus Induces Apoptotic Cell Death in Mammalian Airway Epithelial Cells
H5N1 Avian Influenza Virus Induces Apoptotic Cell Death in Mammalian Airway Epithelial Cells
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DOI：
10.1128/jvi.01192-08
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发表时间：
2008-11-15
影响因子：
5.4
通讯作者：
Nakaya, Takaaki
中科院分区：
文献类型：
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作者：
Daidoji, Tomo;Koma, Takaaki;Nakaya, Takaaki
近年来，高致病性禽流感病毒H5 N1引起了全世界对流感大流行的严重关注;然而，H5 N1致病机理的生物学在很大程度上是未知的。为了阐明H5 N1致病机制，我们从1岁猪的肺泡组织中制备了原代气道上皮细胞，并测量了三种禽H5流感病毒的生长动力学（A/Crow/京都/53/2004 [H5 N1]、A/Duck/Hong Kong/342/78 [H5 N2]和A/Duck/Hong Kong/820/80 [H5 N3]），所产生的细胞病变，以及可能的相关机制。H5 N1，但不是其他H5病毒，强烈诱导细胞死亡，在猪肺泡上皮细胞（pAEpC），虽然所有三种病毒诱导类似程度的细胞病变，在鸡胚胎成纤维细胞。在用每种H5病毒感染的pAEpC中，细胞内病毒生长和子代病毒的产生是相当的。相反，末端脱氧核苷酸转移酶介导的dUTP-生物素缺口末端标记阳性细胞仅在H5 N1感染的pAEpC中检测到，并且半胱氨酸天冬氨酸蛋白酶3、8和9的活性在H5 N1感染的pAEpC中显著升高，但在H5 N2和H5 N3感染的pAEpC中没有。这些结果表明，只有H5 N1在pAEpC中诱导凋亡。通过加入半胱天冬酶抑制剂z-VAD-FMK抑制H5 N1细胞病变;然而，在病毒生长或子代病毒释放方面没有显著差异。使用反向遗传学的进一步研究表明，H5 N1血凝素蛋白在感染的pAEpC中诱导半胱天冬酶依赖性凋亡中起关键作用。在人原代气道上皮细胞中也观察到H5 N1特异性细胞病变。综上所述，这些数据表明，禽H5 N1流感病毒导致哺乳动物气道上皮细胞的大量细胞死亡，由于诱导细胞凋亡。
In recent years, the highly pathogenic avian influenza virus H5N1 has raised serious worldwide concern about an influenza pandemic; however, the biology of H5N1 pathogenesis is largely unknown. To elucidate the mechanism of H5N1 pathogenesis, we prepared primary airway epithelial cells from alveolar tissues from 1-year-old pigs and measured the growth kinetics of three avian H5 influenza viruses (A/Crow/Kyoto/53/2004 [ H5N1], A/Duck/Hong Kong/342/78 [H5N2], and A/Duck/Hong Kong/820/80 [H5N3]), the resultant cytopathicity, and possible associated mechanisms. H5N1, but not the other H5 viruses, strongly induced cell death in porcine alveolar epithelial cells (pAEpC), although all three viruses induced similar degrees of cytopathicity in chicken embryonic fibroblasts. Intracellular viral growth and the production of progeny viruses were comparable in pAEpC infected with each H5 virus. In contrast, terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling-positive cells were detected only in H5N1-infected pAEpC, and the activities of caspases 3, 8, and 9 were significantly elevated in pAEpC infected with H5N1, but not with H5N2 and H5N3. These results suggest that only H5N1 induces apoptosis in pAEpC. H5N1 cytopathicity was inhibited by adding the caspase inhibitor z-VAD-FMK; however, there were no significant differences in viral growth or release of progeny viruses. Further investigations using reverse genetics demonstrated that H5N1 hemagglutinin protein plays a critical role in inducing caspase-dependent apoptosis in infected pAEpC. H5N1-specific cytopathicity was also observed in human primary airway epithelial cells. Taken together, these data suggest that avian H5N1 influenza virus leads to substantial cell death in mammalian airway epithelial cells due to the induction of apoptosis.