title: H5N1 avian influenza virus induces apoptotic cell death in mammalian airway epithelial cells.
abstract: 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.
authors.affiliation: International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, 3-1, Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors.forename: Tomo
authors.initials: T
authors.lastname: Daidoji
authors.forename: Takaaki
authors.initials: T
authors.lastname: Koma
authors.forename: Anariwa
authors.initials: A
authors.lastname: Du
authors.forename: Cheng-Song
authors.initials: CS
authors.lastname: Yang
authors.forename: Mayo
authors.initials: M
authors.lastname: Ueda
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Ikuta
authors.forename: Takaaki
authors.initials: T
authors.lastname: Nakaya
mesh_terms: D000818:Animals; D017209:Apoptosis; D020169:Caspases / Q000378:metabolism; D002460:Cell Line; D002478:Cells, Cultured; D002645:Chickens; D003588:Cytopathogenic Effect, Viral; D004847:Epithelial Cells / Q000821:virology*; D005347:Fibroblasts; D006801:Humans; D020287:In Situ Nick-End Labeling; D053124:Influenza A Virus, H5N1 Subtype / Q000254:growth & development / Q000502:physiology*; D008969:Molecular Sequence Data; D012367:RNA, Viral / Q000235:genetics; D020545:Respiratory Mucosa / Q000821:virology*; D017422:Sequence Analysis, DNA; D013552:Swine
chemical_list: D012367:RNA, Viral; D020169:Caspases
references.citation: J Immunol. 1999 Aug 15;163(4):2217-25
references.pmid: 10438964
references.citation: Lancet. 2004 Feb 21;363(9409):617-9
references.pmid: 14987888
references.citation: Nature. 2006 Mar 23;440(7083):435-6
references.pmid: 16554799
references.citation: Proc Natl Acad Sci U S A. 2008 Feb 26;105(8):3064-9
references.pmid: 18287069
references.citation: J Virol. 2002 Feb;76(4):1617-25
references.pmid: 11799156
references.citation: Proc Natl Acad Sci U S A. 2002 Oct 15;99(21):13849-54
references.pmid: 12368467
references.citation: Arch Virol. 2006 Jul;151(7):1267-79
references.pmid: 16502281
references.citation: Vaccine. 2007 Jul 26;25(30):5637-44
references.pmid: 17126960
references.citation: Virology. 1995 Jun 1;209(2):664-70
references.pmid: 7778300
references.citation: Nat Rev Cancer. 2002 Jun;2(6):420-30
references.pmid: 12189384
references.citation: Oncogene. 2003 Nov 24;22(53):8543-67
references.pmid: 14634618
references.citation: Lancet. 2006 Jan 7;367(9504):84
references.pmid: 16399159
references.citation: J Virol. 2007 Apr;81(7):3058-67
references.pmid: 17229704
references.citation: Emerg Infect Dis. 2005 Jul;11(7):1036-41
references.pmid: 16022777
references.citation: J Virol. 1998 Sep;72(9):7367-73
references.pmid: 9696833
references.citation: Pharm Res. 2006 Sep;23(9):2078-93
references.pmid: 16952001
references.citation: Am J Physiol Lung Cell Mol Physiol. 2002 Dec;283(6):L1315-21
references.pmid: 12388377
references.citation: EMBO J. 2003 Jun 2;22(11):2717-28
references.pmid: 12773387
references.citation: Intervirology. 1993;35(1-4):16-25
references.pmid: 8407243
references.citation: J Cell Biol. 1993 Oct;123(1):7-22
references.pmid: 8408207
references.citation: J Virol. 2006 Aug;80(15):7469-80
references.pmid: 16840327
references.citation: Nat Med. 2001 Dec;7(12):1306-12
references.pmid: 11726970
references.citation: Pediatr Infect Dis J. 2005 Feb;24(2):162-6
references.pmid: 15702046
references.citation: In Vitro Cell Dev Biol Anim. 2004 Nov-Dec;40(10):303-11
references.pmid: 15780007
references.citation: Res Commun Chem Pathol Pharmacol. 1992 Jan;75(1):39-48
references.pmid: 1352645
references.citation: J Virol. 1994 Jun;68(6):3667-73
references.pmid: 8189504
references.citation: J Virol. 2006 Aug;80(16):8060-8
references.pmid: 16873262
references.citation: Oncogene. 2004 Apr 12;23(16):2861-74
references.pmid: 15077149
references.citation: Avian Dis. 1994 Jan-Mar;38(1):151-7
references.pmid: 8002884
references.citation: J Gen Virol. 1993 Nov;74 ( Pt 11):2347-55
references.pmid: 7504071
references.citation: Emerg Infect Dis. 2005 Feb;11(2):201-9
references.pmid: 15752436
references.citation: Proc Natl Acad Sci U S A. 2004 Mar 30;101(13):4620-4
references.pmid: 15070767
references.citation: Avian Dis. 1992 Oct-Dec;36(4):926-31
references.pmid: 1485875
references.citation: J Gen Virol. 1999 Jan;80 ( Pt 1):137-146
references.pmid: 9934696
references.citation: Herz. 1999 May;24(3):189-95
references.pmid: 10412642
references.citation: Biochemistry (Mosc). 2002 May;67(5):534-9
references.pmid: 12059772
references.citation: Glycoconj J. 2006 Feb;23(1-2):101-6
references.pmid: 16575527
references.citation: Cell. 1997 Nov 14;91(4):443-6
references.pmid: 9390553
references.citation: Avian Dis. 1994 Jan-Mar;38(1):22-32
references.pmid: 8002896
references.citation: Am J Respir Crit Care Med. 1995 Oct;152(4 Pt 2):S25-30
references.pmid: 7551408
references.citation: Emerg Infect Dis. 2007 May;13(5):708-12
references.pmid: 17553248
references.citation: Virus Res. 2008 Sep;136(1-2):91-7
references.pmid: 18550190
references.citation: J Med Virol. 2001 Mar;63(3):242-6
references.pmid: 11170064
references.citation: Respir Res. 2005 Nov 11;6:135
references.pmid: 16283933
references.citation: J Gen Virol. 1994 Feb;75 ( Pt 2):371-9
references.pmid: 8113758
references.citation: J Vet Med Sci. 2005 Nov;67(11):1193-6
references.pmid: 16327236
references.citation: Chest. 2006 Jan;129(1):156-68
references.pmid: 16424427
references.citation: J Virol. 2007 May;81(10):5181-91
references.pmid: 17344280
references.citation: J Virol. 2001 Sep;75(17):7875-81
references.pmid: 11483732
references.citation: J Virol. 2004 Nov;78(22):12665-7
references.pmid: 15507653
references.citation: Clin Infect Dis. 2002 May 1;34 Suppl 2:S58-64
references.pmid: 11938498
references.citation: Proc Natl Acad Sci U S A. 2001 Feb 27;98(5):2746-51
references.pmid: 11226311
references.citation: N Engl J Med. 2005 Sep 29;353(13):1374-85
references.pmid: 16192482
references.citation: J Gen Virol. 1997 Nov;78 ( Pt 11):2821-9
references.pmid: 9367368
references.citation: Hepatology. 2005 Feb;41(2):247-56
references.pmid: 15660384
references.citation: Vet Pathol. 1997 Nov;34(6):557-67
references.pmid: 9396136
references.citation: PLoS Pathog. 2005 Sep;1(1):e4
references.pmid: 16201016
references.citation: Nature. 2004 Oct 7;431(7009):703-7
references.pmid: 15470432
references.citation: J Pharmacol Exp Ther. 2000 Sep;294(3):793-9
references.pmid: 10945826
references.citation: J Virol. 1999 Nov;73(11):9679-82
references.pmid: 10516084
references.citation: Am J Pathol. 1997 Oct;151(4):999-1007
references.pmid: 9327733
references.citation: Science. 2005 Oct 7;310(5745):77-80
references.pmid: 16210530
references.citation: J Virol. 2008 Mar;82(6):2741-51
references.pmid: 18199656