title: Immunohistochemical localization of B7 costimulating molecules and major histocompatibility complex class II antigen in pulmonary sarcoidosis.
abstract: BACKGROUND
  Alveolar macrophages (AM) of sarcoidosis have an enhanced capacity to mediate antigen-induced T lymphocyte proliferation. To induce an effective immune response, antigen-presenting cells have to not only present antigenic peptide with MHC molecules to T lymphocytes, but also express B7 costimulating molecules.
  
  
  OBJECTIVE
  The purpose of this study was to investigate the expression of B7 and MHC molecules in lung tissues from patients with sarcoidosis.
  
  
  METHODS
  We performed immunohistochemistry for B7-1, B7-2 and MHC class II antigens using transbronchial lung biopsy specimens obtained from patients with sarcoidosis and normal lung parenchyma obtained by lobectomy for solitary pulmonary nodule as controls.
  
  
  RESULTS
  B7-1, B7-2 and MHC class II antigen were expressed in epithelioid cells in granulomas in 14 (93.3%), 2 (13.3%) and 9 (60.0%) of 15 patients with sarcoidosis, respectively. These were also expressed in AM in 14 (93. 3%), 5 (33.3%) and 12 (80.0%) of 15 patients with sarcoidosis, respectively. The positivity of B7-1 was significantly higher than that of B7-2 in both epithelioid cells and AM in sarcoidosis (p < 0. 01). Positive signals for B7-1, B7-2 and MHC class II antigen were also found in AM in 9 (90%), 8 (80%) and 8 (80%) of 15 of controls, respectively. However, the intensity of positive signals for B7-1, but not B7-2 or MHC class II antigen in AM was significantly increased in sarcoidosis compared to controls (p < 0.05).
  
  
  CONCLUSIONS
  These results suggested that epithelioid cells in granulomas and AM from patients with sarcoidosis had the capability to act as accessory cells and that the accessory function of these cells was shifted to B7-1 rather than B7-2 in sarcoidosis.
authors.affiliation: Research Institute for Diseases of the Chest, Faculty of Medicine, Kyushi University, 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: H
authors.initials: H
authors.lastname: Miyazaki
authors.forename: T
authors.initials: T
authors.lastname: Maeyama
authors.forename: T
authors.initials: T
authors.lastname: Tanaka
authors.forename: T
authors.initials: T
authors.lastname: Matsuba
authors.forename: N
authors.initials: N
authors.lastname: Hara
mesh_terms: D018122:B7-1 Antigen / Q000276:immunology*; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D005260:Female; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006801:Humans; D007124:Immunoenzyme Techniques; D016676:Macrophages, Alveolar / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D017565:Sarcoidosis, Pulmonary / Q000276:immunology*
chemical_list: D018122:B7-1 Antigen; D000949:Histocompatibility Antigens Class II