Preferential accumulation of CD103+ T cells in human livers; its association with extrathymic T cells.
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.
Shimizu
Yukihiro
Y
The Third Department of Internal Medicine, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama 930-0194, Japan. yukihiro-tym@umin.ac.jp
Minemura
Masami
M
Murata
Hiroyuki
H
Hirano
Katsuharu
K
Nakayama
Yasuhiro
Y
Higuchi
Kiyohiro
K
Watanabe
Akiharu
A
Yasuyama
Toshifumi
T
Tsukada
Kazuhiro
K
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
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