title: [Immuno-histological and-cytological examinations on distribution of newly reported co-stimulatory molecules in germinal center of human tonsils].
abstract: OBJECTIVE
  Co-stimulatory molecules are important for cell-cell interactions between immune cells, not only for cell activation, but for suppression. Several new co-stimulatory molecules have recently been discovered, and in this study we used immuno-histological and -cytological methods to investigate the distribution of such molecules in the germinal center of human tonsils.
  
  
  METHODS
  Tonsils surgically removed from patients with sleep apnea and habitual tonsillitis were examined. Expression of co-stimulatory molecules in immune cells was investigated immuno-histologically in frozen sections, and immuno-cytologically by flow cytometry.
  
  
  RESULTS
  PD-L1 was found to be expressed on both GCDCs (germinal center dendritic cells) and FDCs (follicular dendritic cells). ICOS and PD-1 were expressed on activated CD4 T cells located in the light zone of the germinal centers. 4-1BB was expressed on the FDCs, in human tonsils, but not on activated T cells.
  
  
  CONCLUSIONS
  GCDCs and FDCs are likely to function not only T cell activation but in negative regulation of T cells through PD-L1 expression. ICOS molecules contributing to positive signals, and PD-1 to negative signals were simultaneously expressed on a subset of activated T cells, suggesting that signal balance between ICOS and PD-1 is important for T-cell fate.
authors.affiliation: Department of Otolaryngology, Juntendo University School of Medicine, Tokyo.
authors.forename: Gen
authors.initials: G
authors.lastname: Sugita
authors.forename: Masato
authors.initials: M
authors.lastname: Fujimori
authors.forename: Katuhisa
authors.initials: K
authors.lastname: Ikeda
mesh_terms: D000328:Adult; D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis* / Q000502:physiology; D000954:Antigens, Surface / Q000032:analysis*; D051017:Apoptosis Regulatory Proteins; D018122:B7-1 Antigen / Q000032:analysis* / Q000502:physiology; D060890:B7-H1 Antigen; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D003713:Dendritic Cells / Q000378:metabolism*; D018858:Germinal Center / Q000166:cytology* / Q000276:immunology*; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D060889:Inducible T-Cell Co-Stimulator Protein; D007376:Interleukin-2 / Q000032:analysis* / Q000502:physiology; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000032:analysis* / Q000502:physiology; D008875:Middle Aged; D014066:Palatine Tonsil; D010455:Peptides / Q000032:analysis* / Q000502:physiology; D061026:Programmed Cell Death 1 Receptor; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D051017:Apoptosis Regulatory Proteins; D018122:B7-1 Antigen; D060890:B7-H1 Antigen; C423236:CD274 protein, human; C556692:ICOS protein, human; D060889:Inducible T-Cell Co-Stimulator Protein; D007376:Interleukin-2; D008562:Membrane Glycoproteins; C105992:PDCD1 protein, human; D010455:Peptides; D061026:Programmed Cell Death 1 Receptor