title: T cell receptor beta chain (TCR-Vbeta) repertoire of circulating CD4(+) CD25(-), CD4(+) CD25(low) and CD4(+) CD25(high) T cells in patients with long-term renal allograft survival.
abstract: The mechanisms underlying maintenance of renal allografts in humans under minimal or conventional immunosuppression are poorly understood. There is evidence that CD4(+) CD25(+) regulatory T cells and clonal deletion, among other mechanisms of tolerance, could play a key role in clinical allograft survival. Twenty-four TCR-Vbeta families were assessed in CD4(+) CD25(-), CD4(+) CD25(low) and CD4(+) CD25(high) T cells from patients with long-term renal allograft survival (LTS), patients exhibiting chronic rejection (ChrRx), patients on dialysis (Dial) and healthy controls (HC) by flow cytometry. LTS patients presented a higher variability in their TCR-Vbeta repertoire, such decreased percentage of Vbeta2(+), Vbeta8a(+) and Vbeta13(+) in CD4(+) CD25(low) and (high) compared with CD4(+) CD25(-) subset and increased Vbeta4 and Vbeta7 families in CD4(+) CD25(high) T cells exclusively. Additionally, LTS patients, particularly those that were not receiving calcineurin inhibitors (CNI), had increased percentages of CD4(+) CD25(high) T cells when compared with Dial (P < 0.05) and ChrRx (P < 0.05) patients. Our results suggest that a differential expression of particular TCR-Vbeta families and high levels of circulating CD4(+) CD25(high) T cells in long-term surviving renal transplant patients could contribute to an active and specific state of immunologic suppression. However, the increase in this T cell subset with regulatory phenotype can be affected by CNI.
authors.affiliation: Grupo de Inmunología Celular e Inmunogenética, Instituto de Investigaciones Médicas, Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia.
authors.forename: Sonia Y
authors.initials: SY
authors.lastname: Velásquez
authors.forename: Luis F
authors.initials: LF
authors.lastname: Arias
authors.forename: Luis F
authors.initials: LF
authors.lastname: García
authors.forename: Cristiam M
authors.initials: CM
authors.lastname: Alvarez
mesh_terms: D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D005434:Flow Cytometry; D006085:Graft Survival / Q000276:immunology; D006801:Humans; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology*; D016030:Kidney Transplantation / Q000276:immunology*; D019520:Living Donors; D008875:Middle Aged; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology*
chemical_list: C508017:IL2RA protein, human; D053645:Interleukin-2 Receptor alpha Subunit; D011948:Receptors, Antigen, T-Cell; D016693:Receptors, Antigen, T-Cell, alpha-beta