title: Regulation of CD27 expression on subsets of mature T-lymphocytes.
abstract: CD27, a lymphocyte-specific member of the TNF/NGF-R family, is expressed on the majority of peripheral blood T cells. Activation of T cells via TCR/CD3 induces high CD27 surface expression and the release of a soluble extracellular part of the molecule. After prolonged activation in vitro, CD27 becomes gradually switched off. There is evidence that also in vivo, CD4+ cells that have persistently been stimulated by Ag, accumulate within the CD45RA-CD27- subset. In addition, an increase of CD27- T cells has been observed under certain immunopathologic conditions and during aging. This study was undertaken to analyze the regulation of CD27 on different T-cell subsets and to determine whether the loss of CD27 expression is an irreversible event and may thereby mark T-cell differentiation. In agreement with earlier findings, all CD4+CD45RA+CD45RO- T cells were found to express CD27, whereas a small fraction of the CD4+CD45RA-CD45RO+ subset lacks the molecule. In contrast, within the CD8+ compartment CD27- subsets were found both in the CD45RA+ and CD45RA- subpopulations. After stimulation with CD3 mAb, both CD27 membrane expression and release was equally up-regulated in CD4+ and CD8+ subpopulations. This stimulus, however, provoked a strikingly predominant up-regulation of membrane CD27 on CD45RO- cells as compared with CD45RA- cells. On CD4+CD45RA-CD27- T cells and long-term grown CD45RA-CD27- TLC, CD27 expression could not be reinduced after stimulation of the TCR/CD3 complex, neither at the protein nor at the mRNA level. Comparison of CD27 expression with its structural homologue FAS/APO-1 showed that down-regulation after prolonged activation is not a general feature of TNF/NGF-R family members. The CD27 ligand was recently identified and was shown to give a co-stimulatory signal to PHA-activated T cells. The restricted up-regulation of CD27 on CD45RA+ cells after T-cell stimulation may point at a discrete role of CD27-CD27 ligand interaction during transition of CD45RO- to CD45RA- T cells. In addition, the CD27 negative phenotype seems a stable reflection of differentiation rather than of activation.
authors.affiliation: Dept. of Clinical Viro-Immunology, Central Laboratory of The Netherlands Red Cross Blood Transfusion Service, Amsterdam.
authors.forename: R Q
authors.initials: RQ
authors.lastname: Hintzen
authors.forename: R
authors.initials: R
authors.lastname: de Jong
authors.forename: S M
authors.initials: SM
authors.lastname: Lens
authors.forename: M
authors.initials: M
authors.lastname: Brouwer
authors.forename: P
authors.initials: P
authors.lastname: Baars
authors.forename: R A
authors.initials: RA
authors.lastname: van Lier
mesh_terms: D015703:Antigens, CD / Q000032:analysis*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis*; D000954:Antigens, Surface / Q000032:analysis; D015704:CD4 Antigens / Q000032:analysis; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D016827:CD8 Antigens / Q000032:analysis; D002478:Cells, Cultured; D006801:Humans; D017493:Leukocyte Common Antigens / Q000032:analysis; D017260:Receptor-CD3 Complex, Antigen, T-Cell / Q000502:physiology; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D019014:fas Receptor
chemical_list: D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D015704:CD4 Antigens; D016827:CD8 Antigens; D017260:Receptor-CD3 Complex, Antigen, T-Cell; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D019014:fas Receptor; D017493:Leukocyte Common Antigens