title: Adult human liver contains CD8pos T cells with naive phenotype, but is not a site for conventional alpha beta T cell development.
abstract: Normal adult human liver (AHL) contains populations of unconventional lymphocytes that have been shown in the mouse to mature locally. The presence of lymphoid progenitors together with IL-7, recombinase-activating gene, and pre-TCR-alpha expression in AHL suggests similar local T cell development activity in humans. Flow cytometry was used to characterize potentially naive hepatic alphabeta-T cells. We looked for evidence of TCR-alphabeta cell development in AHL by quantifying delta deletion TCR excision circles (TRECs) in CD3(pos) populations isolated from the liver and matched blood of eight individuals. Phenotypic analysis of hepatic T cells suggests the presence of Ag-inexperienced populations. TRECs were detected in all blood samples (mean, 164.10 TRECs/ micro g DNA), whereas only two hepatic samples were positive at low levels (59.40 and 1.92). The relatively high level of CD8(pos) T cells in these livers with a naive phenotype suggests that in addition to its role as a graveyard for Ag-specific activated CD8(pos) T cells, naive CD8(pos) T cells may enter the liver without prior activation. The almost complete absence of TRECs suggests that normal AHL is not a site for the development of conventional alphabeta T cells.
authors.affiliation: Education and Research Center, St. Vincent's University Hospital, Dublin, Ireland. lucy.golden@ucd.ie
authors.forename: Lucy
authors.initials: L
authors.lastname: Golden-Mason
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Douek
authors.forename: Richard A
authors.initials: RA
authors.lastname: Koup
authors.forename: Jacinta
authors.initials: J
authors.lastname: Kelly
authors.forename: John E
authors.initials: JE
authors.lastname: Hegarty
authors.forename: Cliona
authors.initials: C
authors.lastname: O'Farrelly
mesh_terms: D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D005260:Female; D005434:Flow Cytometry; D015329:Gene Rearrangement, T-Lymphocyte; D006801:Humans; D016130:Immunophenotyping; D007399:Interphase / Q000276:immunology; D008099:Liver / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009928:Organ Specificity / Q000235:genetics / Q000276:immunology; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000096:biosynthesis* / Q000097:blood / Q000235:genetics; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000096:biosynthesis
chemical_list: D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta