tetano
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The NS segment of H5N1 avian influenza viruses (AIV) enhances the virulence of an H7N1 AIV in chickens
J?lia Vergara-Alert, N?ria Busquets, Maria Ballester, Aida J Chaves, Raquel Rivas, Roser Dolz, Zhongfang Wang, Stephan Pleschka, Nat?lia Maj?, Fernando Rodr?guez and Ayub Darji
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Veterinary Research 2014, 45:7 doi:10.1186/1297-9716-45-7
Published: 25 January 2014
Abstract (provisional)
Some outbreaks involving highly pathogenic avian influenza viruses (HPAIV) of subtypes H5 and H7 were caused by avian-to-human transmissions. In nature, different influenza A viruses can reassort leading to new viruses with new characteristics. We decided to investigate the impact that the NS-segment of H5 HPAIV would have on viral pathogenicity of a classical avian H7 HPAIV in poultry, a natural host. We focussed this study based on our previous work that demonstrated that single reassortment of the NS-segment from an H5 HPAIV into an H7 HPAIV changes the ability of the virus to replicate in mammalian hosts. Our present data show that two different H7-viruses containing an NS-segment from H5-types (FPV NS GD or FPV NS VN) show an overall highly pathogenic phenotype compared with the wild type H7-virus (FPV), as characterized by higher viral shedding and earlier manifestation of clinical signs. Correlating with the latter, higher amounts of IFN-beta mRNA were detected in the blood of NS-reassortant infected birds, 48 h post-infection (pi). Although lymphopenia was detected in chickens from all AIV-infected groups, also 48 h pi those animals challenged with NS-reassortant viruses showed an increase of peripheral monocyte/macrophage-like cells expressing high levels of IL-1beta, as determined by flow cytometry. Taken together, these findings highlight the importance of the NS-segment in viral pathogenicity which is directly involved in triggering antiviral and pro-inflammatory cytokines found during HPAIV pathogenesis in chickens.
full article
http://www.veterinaryresearch.org/content/pdf/1297-9716-45-7.pdf
J?lia Vergara-Alert, N?ria Busquets, Maria Ballester, Aida J Chaves, Raquel Rivas, Roser Dolz, Zhongfang Wang, Stephan Pleschka, Nat?lia Maj?, Fernando Rodr?guez and Ayub Darji
Author Affiliations
For all author emails, please log on.
Veterinary Research 2014, 45:7 doi:10.1186/1297-9716-45-7
Published: 25 January 2014
Abstract (provisional)
Some outbreaks involving highly pathogenic avian influenza viruses (HPAIV) of subtypes H5 and H7 were caused by avian-to-human transmissions. In nature, different influenza A viruses can reassort leading to new viruses with new characteristics. We decided to investigate the impact that the NS-segment of H5 HPAIV would have on viral pathogenicity of a classical avian H7 HPAIV in poultry, a natural host. We focussed this study based on our previous work that demonstrated that single reassortment of the NS-segment from an H5 HPAIV into an H7 HPAIV changes the ability of the virus to replicate in mammalian hosts. Our present data show that two different H7-viruses containing an NS-segment from H5-types (FPV NS GD or FPV NS VN) show an overall highly pathogenic phenotype compared with the wild type H7-virus (FPV), as characterized by higher viral shedding and earlier manifestation of clinical signs. Correlating with the latter, higher amounts of IFN-beta mRNA were detected in the blood of NS-reassortant infected birds, 48 h post-infection (pi). Although lymphopenia was detected in chickens from all AIV-infected groups, also 48 h pi those animals challenged with NS-reassortant viruses showed an increase of peripheral monocyte/macrophage-like cells expressing high levels of IL-1beta, as determined by flow cytometry. Taken together, these findings highlight the importance of the NS-segment in viral pathogenicity which is directly involved in triggering antiviral and pro-inflammatory cytokines found during HPAIV pathogenesis in chickens.
full article
http://www.veterinaryresearch.org/content/pdf/1297-9716-45-7.pdf