title: Important role of interferon regulatory factor (IRF)-3 in the interferon response of mouse macrophages upon infection by Newcastle disease virus.
abstract: Newcastle disease virus (NDV) is an interesting agent for activating innate immune activity in macrophages including secretion of TNF-α and IFN-α, upregulation of TRAIL and activation of NF-κB and iNOS. However, the molecular mechanism of such cellular activities remains largely unknown. Tumor selectivity of replication of NDV has been described to be linked to deviations in tumor cells of the type I interferon response. We therefore focused on the interferon response to NDV of macrophages as part of innate anti-viral and anti-tumor activity. In particular, we investigated the functional significance of the interferon regulatory factor genes (IRF)-3 and IRF-7. Deletion of the IRF-3 or IRF-7 gene was found to increase susceptibility of mouse macrophages to virus infection. Surprisingly, NDV replicated better in IRF-3 KO than in IRF-7 KO macrophages. Further analysis showed that IRF-3 KO macrophages have a lower basal and NDV-induced RIG-I expression in comparison to IRF-7 KO macrophages. This might explain why, in IRF-3 KO macrophages, the secretion of type I interferons after NDV infection is delayed, when compared to IRF-7 KO and wild-type macrophages. In addition, IRF-3 KO cells showed reduced NDV-induced levels of IRF-7. This effect could be prevented by priming the cells first by interferon-α. Further results indicated that an early production of type I interferon rather than high maximal levels at later time points are important for resistance to infection by NDV. In conclusion, these results demonstrate an important role of IRF-3 for the innate anti-viral response to NDV of mouse macrophages.
authors.affiliation: German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Wilden
authors.forename: Volker
authors.initials: V
authors.lastname: Schirrmacher
authors.forename: Philippe
authors.initials: P
authors.lastname: Fournier
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics; D007113:Immunity, Innate / Q000235:genetics / Q000276:immunology; D050838:Interferon Regulatory Factor-3 / Q000235:genetics / Q000276:immunology*; D050839:Interferon Regulatory Factor-7 / Q000235:genetics / Q000378:metabolism; D007370:Interferon Type I / Q000378:metabolism; D007372:Interferons / Q000276:immunology*; D008264:Macrophages / Q000187:drug effects / Q000276:immunology* / Q000821:virology*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D009521:Newcastle Disease / Q000235:genetics / Q000276:immunology; D009522:Newcastle disease virus / Q000502:physiology*; D011956:Receptors, Cell Surface; D014779:Virus Replication; D000097905:Roundabout Proteins
chemical_list: D050838:Interferon Regulatory Factor-3; D050839:Interferon Regulatory Factor-7; D007370:Interferon Type I; D007372:Interferons; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D011956:Receptors, Cell Surface; C118348:Robo3 protein, mouse; D000097905:Roundabout Proteins