title: Characterization of the Localized Immune Response in the Respiratory Tract of Ferrets following Infection with Influenza A and B Viruses.
abstract: The burden of infection with seasonal influenza viruses is significant. Each year is typically characterized by the dominance of one (sub)type or lineage of influenza A or B virus, respectively. The incidence of disease varies annually, and while this may be attributed to a particular virus strain or subtype, the impacts of prior immunity, population differences, and variations in clinical assessment are also important. To improve our understanding of the impacts of seasonal influenza viruses, we directly compared clinical symptoms, virus shedding, and expression of cytokines, chemokines, and immune mediators in the upper respiratory tract (URT) of ferrets infected with contemporary A(H1N1)pdm09, A(H3N2), or influenza B virus. Gene expression in the lower respiratory tract (LRT) was also assessed. Clinical symptoms were minimal. Overall cytokine/chemokine profiles in the URT were consistent in pattern and magnitude between animals infected with influenza A and B viruses, and peak expression levels of interleukin-1α (IL-1α), IL-1β, IL-6, IL-12p40, alpha interferon (IFN-α), IFN-β, and tumor necrosis factor alpha (TNF-α) mRNAs correlated with peak levels of viral shedding. MCP1 and IFN-γ were expressed after the virus peak. Granzymes A and B and IL-10 reached peak expression as the virus was cleared and seroconversion was detected. Cytokine/chemokine gene expression in the LRT following A(H1N1)pdm09 virus infection reflected the observations seen for the URT but was delayed 2 or 3 days, as was virus replication. These data indicate that disease severities and localized immune responses following infection with seasonal influenza A and B viruses are similar, suggesting that other factors are likely to modulate the incidence and impact of seasonal influenza.
  
  
  OBJECTIVE
  Both influenza A and B viruses cocirculate in the human population, and annual influenza seasons are typically dominated by an influenza A virus subtype or an influenza B virus lineage. Surveillance data indicate that the burden of disease is higher in some seasons, yet it is unclear whether this is due to specific virus strains or to other factors, such as cross-reactive immunity or clinical definitions of influenza. We directly compared disease severities and localized inflammatory responses to different seasonal influenza virus strains, including the 2009 pandemic strain, in healthy naive ferrets. We found that the disease severities and the cytokine and chemokine responses were similar irrespective of the seasonal strain or the location of the infection in the respiratory tract. This suggests that factors other than the immune response to a particular virus (sub)type contribute to the variable impact of influenza virus infection in a population.
authors.affiliation: WHO Collaborating Centre for Reference and Research on Influenza, Victorian Infectious Diseases Reference Laboratory, Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia.
authors.forename: Louise A
authors.initials: LA
authors.lastname: Carolan
authors.affiliation: bioCSL Limited, Parkville, Victoria, Australia Department of Microbiology and Immunology, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Steve
authors.initials: S
authors.lastname: Rockman
authors.affiliation: WHO Collaborating Centre for Reference and Research on Influenza, Victorian Infectious Diseases Reference Laboratory, Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia School of Applied and Biomedical Sciences, Federation University, Churchill, Victoria, Australia.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Borg
authors.affiliation: WHO Collaborating Centre for Reference and Research on Influenza, Victorian Infectious Diseases Reference Laboratory, Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia School of Applied and Biomedical Sciences, Federation University, Churchill, Victoria, Australia.
authors.forename: Teagan
authors.initials: T
authors.lastname: Guarnaccia
authors.affiliation: WHO Collaborating Centre for Reference and Research on Influenza, Victorian Infectious Diseases Reference Laboratory, Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia.
authors.forename: Patrick
authors.initials: P
authors.lastname: Reading
authors.affiliation: School of Applied and Biomedical Sciences, Federation University, Churchill, Victoria, Australia.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Mosse
authors.affiliation: WHO Collaborating Centre for Reference and Research on Influenza, Victorian Infectious Diseases Reference Laboratory, Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia.
authors.forename: Anne
authors.initials: A
authors.lastname: Kelso
authors.affiliation: WHO Collaborating Centre for Reference and Research on Influenza, Victorian Infectious Diseases Reference Laboratory, Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia.
authors.forename: Ian
authors.initials: I
authors.lastname: Barr
authors.affiliation: WHO Collaborating Centre for Reference and Research on Influenza, Victorian Infectious Diseases Reference Laboratory, Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia Karen.laurie@influenzacentre.org.
authors.forename: Karen L
authors.initials: KL
authors.lastname: Laurie
mesh_terms: D000818:Animals; D001831:Body Temperature; D001835:Body Weight; D016207:Cytokines / Q000032:analysis; D004195:Disease Models, Animal; D005260:Female; D005289:Ferrets; D020869:Gene Expression Profiling; D006801:Humans; D009980:Influenza A virus / Q000276:immunology*; D009981:Influenza B virus / Q000276:immunology*; D008297:Male; D009976:Orthomyxoviridae Infections / Q000276:immunology* / Q000473:pathology* / Q000821:virology; D012137:Respiratory System / Q000276:immunology* / Q000473:pathology* / Q000821:virology; D012720:Severity of Illness Index; D019562:Viral Load; D017201:Virus Shedding
chemical_list: D016207:Cytokines