title: Resolution of immune response by recombinant transforming growth factor-beta (rTGF-β) during influenza A virus infection.
abstract: OBJECTIVE
  Replication of influenza A virus in the respiratory tract leads to cell damage and liberation of cytokines and chemokines. The in vivo cytokine induction and modulation by recombinant transforming growth factor- β1 (rTGF-β1) has not been studied. Therefore, in the present study the effect of rTGF-β1, a potent immunomodulatory cytokine which has anti-inflammatory properties and downregulates the release of inflammatory molecules, against influenza-virus infection in the airway of mice was investigated.
  
  
  METHODS
  rTGF-β1 was administered intravenously to mice with concomitant intranasal infection of influenza A/Udorn/317/72 (H3N2) virus, and the survival rate, virus titre, histopathological changes and levels of factors regulating inflammation in the airway fluid were analysed.
  
  
  RESULTS
  The immune response to influenza A virus was characterized by an influx of both macrophages and lymphocytes into the lungs of the infected host. rTGF-β1 significantly suppressed virus multiplication and improved the survival rate of mice. rTGF-β1 downregulated infiltration of neutrophils and the release of inflammatory molecules, such as interferon-gamma (IFN-γ), interleukin-1 β (IL-1β) and stimulated release of IL-10 that potentiates anti-inflammatory response into airway.
  
  
  CONCLUSIONS
  A generalized pulmonary inflammation does not contribute to viral clearance but represents an immunological background within which antiviral immunity operates. Treatment with rTGF-β1 reduced macrophage count and neutrophils influx in lungs of infected mice.
authors.affiliation: Department of Respiratory Virology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India.
authors.forename: Vikram
authors.initials: V
authors.lastname: Srivastava
authors.forename: Madhu
authors.initials: M
authors.lastname: Khanna
authors.forename: Sonal
authors.initials: S
authors.lastname: Sharma
authors.forename: Binod
authors.initials: B
authors.lastname: Kumar
mesh_terms: D061605:Administration, Intravenous; D000704:Analysis of Variance; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology; D016207:Cytokines / Q000276:immunology; D009980:Influenza A virus; D008168:Lung / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology; D008264:Macrophages / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D009976:Orthomyxoviridae Infections / Q000276:immunology*; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000276:immunology / Q000494:pharmacology*; D012137:Respiratory System / Q000821:virology*; D015996:Survival Rate; D016212:Transforming Growth Factor beta / Q000008:administration & dosage / Q000276:immunology / Q000494:pharmacology*; D014779:Virus Replication / Q000276:immunology*
chemical_list: D016207:Cytokines; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta