title: B7-1, B7-2 and class II MHC molecules in idiopathic pulmonary fibrosis and bronchiolitis obliterans-organizing pneumonia.
abstract: Interstitial lung diseases are thought to be associated with the infiltration of activated T-lymphocytes. To induce an effective immune response, antigen-presenting cells have to not only present antigenic peptide with major histocompatibility complex (MHC) molecules to T-lymphocytes but also express B7 molecules. Therefore, the expression of B7-1, B7-2 and class II MHC molecules was investigated in lung tissues from patients with idiopathic pulmonary fibrosis (IPF) and bronchiolitis obliterans-organizing pneumonia (BOOP), and in normal lung parenchyma as a control, using immunohistochemical localization. B7-1 and B7-2 were aberrantly expressed in bronchiolar and alveolar epithelial cells, and class II MHC molecules were also aberrantly expressed in bronchiolar epithelial cells in IPF. B7-1 was aberrantly expressed in bronchiolar epithelial cells in BOOP. There was no significant difference in the expression of these proteins in alveolar macrophages between IPF and control subjects. However, B7-2 and class II MHC molecule expression in alveolar macrophages was decreased in BOOP compared with that in control subjects. Expression of CD28 and CTLA4, receptors for B7 molecules, was detected in infiltrating lymphocytes in lung tissues in IPF and BOOP. It was concluded that bronchiolar and alveolar epithelial cells may actively participate in the pathophysiology of idiopathic pulmonary fibrosis through the aberrant expression of B7 and class II major histocompatibility complex molecules. The dysregulation of these molecules in epithelial cells may lead to the activation of autoreactive T-lymphocytes, which might contribute to the pathogenesis of fibrosing lung diseases.
authors.affiliation: Research Institute for Diseases of the Chest, Faculty of Medicine, Kyushu University, Higashiku, Fukuoka, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kaneko
authors.forename: K
authors.initials: K
authors.lastname: Kuwano
authors.forename: R
authors.initials: R
authors.lastname: Kunitake
authors.forename: M
authors.initials: M
authors.lastname: Kawasaki
authors.forename: N
authors.initials: N
authors.lastname: Hagimoto
authors.forename: N
authors.initials: N
authors.lastname: Hara
mesh_terms: D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000032:analysis*; D018122:B7-1 Antigen / Q000032:analysis*; D051940:B7-2 Antigen; D001706:Biopsy; D001980:Bronchi / Q000276:immunology / Q000473:pathology; D001989:Bronchiolitis Obliterans / Q000276:immunology / Q000473:pathology*; D018549:Cryptogenic Organizing Pneumonia / Q000276:immunology / Q000473:pathology*; D005260:Female; D000949:Histocompatibility Antigens Class II / Q000032:analysis*; D006801:Humans; D008168:Lung / Q000276:immunology / Q000473:pathology; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis*; D008875:Middle Aged; D011650:Pulmonary Alveoli / Q000276:immunology / Q000473:pathology; D011658:Pulmonary Fibrosis / Q000276:immunology / Q000473:pathology*; D020545:Respiratory Mucosa / Q000276:immunology / Q000473:pathology; D013601:T-Lymphocytes / Q000276:immunology / Q000473:pathology
chemical_list: D015703:Antigens, CD; D018122:B7-1 Antigen; D051940:B7-2 Antigen; C497964:CD86 protein, human; D000949:Histocompatibility Antigens Class II; D008562:Membrane Glycoproteins