title: Increased resistance to CD4+CD25hi regulatory T cell-mediated suppression in patients with type 1 diabetes.
abstract: Type I diabetes (T1D) is a T cell-mediated autoimmune disease characterized by loss of tolerance to islet autoantigens, leading to the destruction of insulin-producing beta cells. Peripheral tolerance to self is maintained in health through several regulatory mechanisms, including a population of CD4+CD25hi naturally occurring regulatory T cells (T(regs)), defects in which could contribute to loss of self-tolerance in patients with T1D. We have reported previously that near to T1D onset, patients demonstrate a reduced level of suppression by CD4+CD25hi T(regs) of autologous CD4+CD25- responder cells. Here we demonstrate that this defective regulation is also present in subjects with long-standing T1D (> 3 years duration; P = 0.009). No difference was observed in forkhead box P3 or CD127 expression on CD4+CD25hi T cells in patients with T1D that could account for this loss of suppression. Cross-over co-culture assays demonstrate a relative resistance to CD4+CD25hi T(reg)-mediated suppression within the CD4+CD25- T cells in all patients tested (P = 0.002), while there appears to be heterogeneity in the functional ability of CD4+CD25hi T(regs) from patients. In conclusion, this work demonstrates that defective regulation is a feature of T1D regardless of disease duration and that an impaired ability of responder T cells to be suppressed contributes to this defect.
authors.affiliation: King's College London, Department of Immunobiology, King's College London, London, UK.
authors.forename: J M
authors.initials: JM
authors.lastname: Lawson
authors.forename: J
authors.initials: J
authors.lastname: Tremble
authors.forename: C
authors.initials: C
authors.lastname: Dayan
authors.forename: H
authors.initials: H
authors.lastname: Beyan
authors.forename: R D G
authors.initials: RD
authors.lastname: Leslie
authors.forename: M
authors.initials: M
authors.lastname: Peakman
authors.forename: T I M
authors.initials: TI
authors.lastname: Tree
mesh_terms: D000328:Adult; D018791:CD4 Lymphocyte Count; D049109:Cell Proliferation; D002478:Cells, Cultured; D018920:Coculture Techniques; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology*; D051858:Forkhead Transcription Factors / Q000097:blood; D006801:Humans; D053645:Interleukin-2 Receptor alpha Subunit / Q000097:blood; D053699:Interleukin-7 Receptor alpha Subunit / Q000097:blood; D008213:Lymphocyte Activation / Q000276:immunology; D008875:Middle Aged; D017634:Self Tolerance / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D053645:Interleukin-2 Receptor alpha Subunit; D053699:Interleukin-7 Receptor alpha Subunit