title: [Airway inflammation induced by Poly(I:C) stimulation in the late stage of respiratory syncytial virus infection in mice and its mechanism].
abstract: OBJECTIVE
  To investigate the pathogenic mechanisms of airway inflammation and recurrent wheezing induced by recurrent respiratory virus infection after respiratory syncytial virus (RSV) infection.
  
  
  METHODS
  Sixty-four female BALB/c mice (aged 6-8 weeks) were randomly divided into four groups: control, RSV, Poly(I:C), and RSV+Poly(I:C) (n=16 each). The bronchoalveolar lavage fluid (BALF) was collected on the 3rd day after Poly(I:C) administration, and the total cell number and differential counts in BALF were determined. Hematoxylin-eosin staining was used to observe pulmonary pathological changes. The airway responsiveness was detected. ELISA was used to measure the levels of interferon-γ (IFN-γ), interleukin-4 (IL-4), interleukin-13 (IL-13), matrix metallopeptidase-9 (MMP-9), and tissue inhibitor of metalloproteinase-1 (TIMP-1) in BALF.
  
  
  RESULTS
  Compared with the other three groups, the RSV+Poly(I:C) group had significant increases in the total number of inflammatory infiltrating cells in the airway, airway responsiveness, and MMP-9 level in BALF (P<0.05). The RSV+Poly(I:C) group showed more severe pulmonary tissue injuries compared with the control and RSV groups (P<0.01). Compared with the RSV group, the RSV+Poly(I:C) group showed significant reductions in the levels of IL-4 and TIMP-1 in BALF (P<0.01).
  
  
  CONCLUSIONS
  Viral re-infection in the late stage of RSV infection may cause an imbalance of MMP-9/TIMP-1 expression and thus contribute to aggravated airway inflammation.
authors.affiliation: Pediatric Research Institute of Children's Hospital of Chongqing Medical University, Chongqing 400014, China. emliu186@126.com.
authors.forename: Ke-Ting
authors.initials: KT
authors.lastname: Zhao
authors.forename: Xiao-Ru
authors.initials: XR
authors.lastname: Long
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Jun
authors.initials: J
authors.lastname: Xie
authors.forename: Luo
authors.initials: L
authors.lastname: Ren
authors.forename: Yu
authors.initials: Y
authors.lastname: Deng
authors.forename: Xiao-Hong
authors.initials: XH
authors.lastname: Xie
authors.forename: Na
authors.initials: N
authors.lastname: Zang
authors.forename: Li-Jia
authors.initials: LJ
authors.lastname: Wang
authors.forename: En-Mei
authors.initials: EM
authors.lastname: Liu
mesh_terms: D000818:Animals; D001249:Asthma / Q000209:etiology*; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D005260:Female; D008168:Lung / Q000473:pathology; D020780:Matrix Metalloproteinase 9 / Q000032:analysis; D051379:Mice; D008807:Mice, Inbred BALB C; D011070:Poly I-C / Q000494:pharmacology*; D018357:Respiratory Syncytial Virus Infections / Q000150:complications*; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000032:analysis
chemical_list: D019715:Tissue Inhibitor of Metalloproteinase-1; D020780:Matrix Metalloproteinase 9; D011070:Poly I-C