title: Functional defects and the influence of age on the frequency of CD4+ CD25+ T-cells in type 1 diabetes.
abstract: CD4+ CD25+ T-cells appear to play a crucial role in regulating the immune response. Therefore, we evaluated the peripheral blood frequency and function of CD4+ CD25+ T-cells in 70 type 1 diabetic patients and 37 healthy individuals. Interestingly, a positive correlation was observed between increasing age and CD4+ CD25+ T-cell frequency in both subject groups. In contrast to previous studies of nonobese diabetic mice and type 1 diabetic patients, similar frequencies of CD4+ CD25+ and CD4+ CD25(+Bright) T-cells were observed in healthy control subjects and type 1 diabetic patients of similar age. There was no difference between type 1 diabetic subjects of recent-onset versus those with established disease in terms of their CD4+ CD25+ or CD4+ CD25(+Bright) T-cell frequency. However, type 1 diabetic patients were markedly defective in their ability to suppress the proliferation of autologous effector T-cells in vitro. This type 1 diabetes-associated defect in suppression was associated with reduced production of interleukin (IL)-2, gamma-interferon, and transforming growth factor-beta, whereas other cytokines including those of adaptive and innate immunity (IL-10, IL-1beta, IL-6, IL-8, IL-12p70, and tumor necrosis factor-alpha) were similar in control subjects and type 1 diabetic patients. These data suggest that age strongly influences the frequency of CD4+ CD25+ T-cells and that function, rather than frequency, may represent the means by which these cells associate with type 1 diabetes in humans.
authors.affiliation: Department of Pathology, Immunology and Laboratory Medicine, College of Medicine, University of Florida, ARB-R3-128, 1600 SW Archer Rd., Gainesville, FL 32610-0275, USA.
authors.forename: Todd M
authors.initials: TM
authors.lastname: Brusko
authors.forename: Clive H
authors.initials: CH
authors.lastname: Wasserfall
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Clare-Salzler
authors.forename: Desmond A
authors.initials: DA
authors.lastname: Schatz
authors.forename: Mark A
authors.initials: MA
authors.lastname: Atkinson
mesh_terms: D000293:Adolescent; D000328:Adult; D000917:Antibody Formation; D015703:Antigens, CD / Q000235:genetics; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000276:immunology*; D005260:Female; D006801:Humans; D007111:Immunity, Cellular; D007165:Immunosuppression Therapy; D008297:Male; D015375:Receptors, Interleukin-2 / Q000235:genetics*; D012016:Reference Values; D016176:T-Lymphocyte Subsets / Q000276:immunology*
chemical_list: D015703:Antigens, CD; D015375:Receptors, Interleukin-2