title: Preferential accumulation of CD103+ T cells in human livers; its association with extrathymic T cells.
abstract: OBJECTIVE
  CD103, a mucosal integrin alphaEbeta7, binds to E-cadherin expressed on hepatocytes and bile duct epithelium in the liver. Although CD103+ T cells are enriched in intestinal intraepithelial lymphocytes, the localization of those cells in the liver is unknown.
  
  
  METHODS
  We investigated whether CD103+ cells are present in human livers, and how they are associated with the intrahepatic development of T cells by flow cytometry and immunohistochemistry.
  
  
  RESULTS
  Human livers contain significantly (P<0.001) higher percentages of CD103+ cells in CD4+ and CD8+ T cells (25.7+/-13.5 and 27.1+/-19.3%, respectively) than peripheral blood lymphocytes. Moreover, CD103+ cells in the liver, but not in peripheral blood, contained T cells with intermediate expression level of T cell receptor alphabeta. Those cells consist of mostly CD4+ and CD4-CD8- cells, and expressed low level of CD56 and interleukin-2 receptor beta chain in most of the population. These characteristics are distinct from natural killer T cells, which have been thought to be extrathymic T cells in human livers. Moreover, intrahepatic CD103+ cells expressed mRNA for recombination-activating gene-1, -2 and pre T cell receptor-alpha detected by reverse transcription-polymerase chain reaction.
  
  
  CONCLUSIONS
  CD103+ T cells are preferentially accumulated in human livers, and those T cells show characteristics of extrathymic T cells.
authors.affiliation: The Third Department of Internal Medicine, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama 930-0194, Japan. yukihiro-tym@umin.ac.jp
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Shimizu
authors.forename: Masami
authors.initials: M
authors.lastname: Minemura
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Murata
authors.forename: Katsuharu
authors.initials: K
authors.lastname: Hirano
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Nakayama
authors.forename: Kiyohiro
authors.initials: K
authors.lastname: Higuchi
authors.forename: Akiharu
authors.initials: A
authors.lastname: Watanabe
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Yasuyama
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Tsukada
mesh_terms: D015703:Antigens, CD / Q000378:metabolism; D015820:Cadherins / Q000378:metabolism; D002465:Cell Movement / Q000276:immunology*; D004268:DNA-Binding Proteins / Q000235:genetics; D005434:Flow Cytometry; D006521:Hepatitis, Chronic / Q000276:immunology*; D018398:Homeodomain Proteins / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D016130:Immunophenotyping; D039001:Integrin alpha Chains / Q000378:metabolism; D008099:Liver / Q000166:cytology* / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000235:genetics; D009687:Nuclear Proteins; D012333:RNA, Messenger / Q000032:analysis; D016693:Receptors, Antigen, T-Cell, alpha-beta; D013601:T-Lymphocytes / Q000166:cytology* / Q000276:immunology / Q000378:metabolism; D013950:Thymus Gland / Q000166:cytology* / Q000276:immunology
chemical_list: D015703:Antigens, CD; D015820:Cadherins; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D039001:Integrin alpha Chains; D008562:Membrane Glycoproteins; D009687:Nuclear Proteins; C499311:RAG2 protein, human; D012333:RNA, Messenger; D016693:Receptors, Antigen, T-Cell, alpha-beta; C064655:V(D)J recombination activating protein 2; C091367:alpha E integrins; C090377:pre-T cell receptor alpha; C064658:RAG-1 protein