title: Activation-induced CD137 is a fast assay for identification and multi-parameter flow cytometric analysis of alloreactive T cells.
abstract: Detection and isolation of viable alloreactive T cells at the single-cell level requires a cell surface marker induced specifically upon T cell receptor activation. In this study, a member of the tumour necrosis factor receptor (TNFR)-family, CD137 (4-1BB) was investigated for its potential to identify the total pool of circulating alloreactive T cells. Optimal conditions for sensitive and specific detection of allogeneic-induced CD137 expression on circulating T cells were established. Thereafter, CD137(+) alloreactive T cells were phenotypically and functionally characterized by multi-parameter flow cytometry. Alloantigen-induced CD137 expression identified both alloreactive CD8(+) T cells (mean ± standard error of the mean: 0·21 ± 0·07%) and alloreactive CD4(+) T cells (0·21 ± 0·05%). CD137(+) alloreactive T cells were detected in different T cell subsets, including naive T cells, but were found preferentially in CD28(+) T cells and not in the terminally differentiated T cell subset. Upon allogeneic (re-)stimulation, the cytokine-producing as well as proliferative capacity of T cells resided mainly within the CD137-expressing fraction. About 10% of the CD137(+) alloreactive T cells produced any combination of interferon (IFN)-γ, interleukin (IL)-2 and TNF-α. Polyfunctional alloreactive T cells, defined by multiple cytokine expression, were observed infrequently. In conclusion, activation-induced CD137 expression is a fast assay allowing for detection and functional analysis of the total alloreactive T cell compartment at the single-cell level by multi-parameter flow cytometry.
authors.affiliation: Department of Internal Medicine, section Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, South-Holland, the Netherlands.
authors.forename: N H R
authors.initials: NH
authors.lastname: Litjens
authors.forename: E A
authors.initials: EA
authors.lastname: de Wit
authors.forename: C C
authors.initials: CC
authors.lastname: Baan
authors.forename: M G H
authors.initials: MG
authors.lastname: Betjes
mesh_terms: D000938:Antigen-Presenting Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D049109:Cell Proliferation; D005434:Flow Cytometry / Q000379:methods* / Q000592:standards; D006801:Humans; D016130:Immunophenotyping / Q000379:methods / Q000592:standards; D007519:Isoantigens / Q000502:physiology*; D008213:Lymphocyte Activation / Q000276:immunology*; D007959:Lymphocyte Culture Test, Mixed / Q000379:methods / Q000592:standards; D008212:Lymphocyte Depletion; D012680:Sensitivity and Specificity; D013234:Stem Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D053261:Tumor Necrosis Factor Receptor Superfamily, Member 9 / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D007519:Isoantigens; D053261:Tumor Necrosis Factor Receptor Superfamily, Member 9
keywords: CD137; CD4+ T cells; CD8+ T cells; alloreactivity; multi-parameter analysis