title: Increased Galectin-9 Concentration and Number of CD4+Foxp3high+Cells in Bronchoalveolar Lavage Fluid of Patients with Cryptogenic Organizing Pneumonia.
abstract: OBJECTIVE
  Galectin-9 (Gal-9) is a β-galactoside-binding protein that exhibits various biological reactions, such as chemoattraction, cell aggregation, and apoptosis. Recent studies demonstrated that Gal-9 has a role as an immunomodulator in excessive immunological reactions by expanded regulatory T cells (Tregs). We examined the role of Gal-9 in the pathogenesis of one of the major idiopathic interstitial pneumonias, cryptogenic organizing pneumonia (COP) as compared with idiopathic pulmonary fibrosis (IPF).
  
  
  METHODS
  Gal-9, transforming growth factor-β1, and interleukin (IL)-10 levels in the bronchoalveolar lavage fluid (BALF) of patients with COP and IPF were estimated by enzyme-linked immunosorbent assay. Forkhead box protein 3 (Foxp3) expressing Tregs were evaluated by flow cytometry. The effect of Gal-9 on interactions between human lung fibroblast cells and hyarulonan was assessed in vitro.
  
  
  RESULTS
  Gal-9 and IL-10 levels in the BALF were significantly higher in patients with COP than in patients with IPF. The number of CD4+Foxp3high+cells was significantly higher in the BALF of patients with COP than in those with IPF. Gal-9 levels significantly correlated with the absolute number of CD4+CD25+Foxp3+cells or CD4+Foxp3high+cells, but not with the absolute number of CD4+CD25+Foxp3-cells, in the BALF of patients with COP. Gal-9 suppressed the CD44-dependent interaction of human lung fibroblast cells with hyarulonan in a dose-dependent manner.
  
  
  CONCLUSIONS
  Our findings suggest that increased Gal-9 levels in the lung have a protective role against lung inflammation and fibrosis in patients with COP through the induction of Tregs in the lung and CD44-dependent inhibitory effects on lung fibroblast cells.
authors.affiliation: Department of Respiratory Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan. kshigeki@med.kawasaki-m.ac.jp.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Katoh
authors.affiliation: Department of Respiratory Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Ikeda
authors.affiliation: Department of Respiratory Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Shimizu
authors.affiliation: Department of Respiratory Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Abe
authors.affiliation: Department of Respiratory Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Ohue
authors.affiliation: Department of Respiratory Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Mouri
authors.affiliation: Department of Respiratory Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kobashi
authors.affiliation: Department of Respiratory Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan.
authors.forename: Mikio
authors.initials: M
authors.lastname: Oka
mesh_terms: D000368:Aged; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry* / Q000276:immunology*; D018791:CD4 Lymphocyte Count; D018549:Cryptogenic Organizing Pneumonia / Q000276:immunology* / Q000378:metabolism*; D005260:Female; D005347:Fibroblasts / Q000502:physiology; D051858:Forkhead Transcription Factors / Q000032:analysis; D037161:Galectins / Q000032:analysis* / Q000378:metabolism; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D006820:Hyaluronic Acid / Q000378:metabolism; D054990:Idiopathic Pulmonary Fibrosis / Q000276:immunology / Q000378:metabolism; D016753:Interleukin-10 / Q000032:analysis; D008297:Male; D050378:T-Lymphocytes, Regulatory / Q000737:chemistry; D053773:Transforming Growth Factor beta1 / Q000032:analysis
chemical_list: C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D037161:Galectins; D018960:Hyaluronan Receptors; C105032:LGALS9 protein, human; D053773:Transforming Growth Factor beta1; D016753:Interleukin-10; D006820:Hyaluronic Acid
keywords: Bronchoalveolar lavage fluid; Cryptogenic organizing pneumonia; Galectin-9; Lung fibrosis; Regulatory T cells