Efficient replication and strong induction of innate immune responses by H9N2 avian influenza virus in human dendritic cells.
: Veera Westenius, Sanna M.Mäkelä a, Thedi Ziegler, Ilkka Julkunen, Pamela Österlund
Publisher: Elsevier Inc.
: 2014
: Virology
: Virology
: 471-473
: 38
: 48
: 11
: 0042-6822
DOI: https://doi.org/10.1016/j.virol.2014.10.002
Avian influenza A (H9N2) viruses have occasionally been identified in humans with upper respiratory tract infections. The novel H7N9/2013 virus identified in China shows that a low pathogenic avian influenza (LPAI) virus can be highly pathogenic in humans. Therefore, it is important to understand virus-host cell interactions and immune responses triggered by LPAI viruses in humans. We found that LPAI A/Hong Kong/1073/99 (H9N2) virus replicated efficiently in human dendritic cells (DCs). The H9N2 virus induced strong IFN gene expression although with different kinetics than seasonal influenza A/Beijing/353/89 (H3N2) virus. IFN inducible antiviral proteins were produced in H9N2 virus-infected cells at the same level as in H3N2 infection. The H9N2 virus was extremely sensitive to the antiviral actions of type I IFNs. These results indicate that the avian influenza H9N2 virus is inducing a strong antiviral IFN response in human DCs.