title: Autoreactive T cell response in CD25-negative fraction of peripheral blood mononuclear cells in established type 1 diabetes.
abstract: CD4(+)CD25(+) T cells (Tregs) play a critical role in maintaining dominant peripheral tolerance, and pathogenic autoreactive T cells may be frequent in the CD25-negative fraction of peripheral blood mononuclear cells (PBMCs) from patients with autoimmune disease. We therefore investigated whether T cell autoimmune responses to recombinant GAD65 can be detected by the use of ELISPOT assay in the CD25-negative fraction of PMBCs from Japanese type 1 diabetes (T1D) patients. The frequency of CD4(+)CD25(+) T cells was not different among patients with newly developed T1D, established T1D, and healthy controls. The CD25 positive cell-depleted fraction was obtained by negative selection with antihuman CD25 magnetic beads, reducing the number of CD4(+)CD25(+) T cells from 4-5% to less than 1%. In whole PBMC fraction, there was a significant elevation of IFN-gamma spots in PBMCs from recently diagnosed patients with T1D (P < 0.05), whereas the number of IFN-gamma spots from patients with established T1D was not significant. In the CD25-negative fraction, unlike whole PBMCs, we observed the significant IFN-gamma spots to GAD65 in the fraction from patients with established T1D (P < 0.05), but not in those with recently diagnosed disease. The phenomena were not observed for IL-4 spots. Our data suggest a possible role of Tregs maintaining dominant peripheral tolerance in T1D and application of further improved T cell assay detecting autoimmunity even in established T1D.
authors.affiliation: Department of Internal and Geriatric Medicine, Kobe University Graduate School of Medicine, Kobe, Japan. hirom@med.kobe-u.ac.jp
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Moriyama
authors.forename: Reiko
authors.initials: R
authors.lastname: Kotani
authors.forename: Atsumi
authors.initials: A
authors.lastname: Katsuta
authors.forename: Mami
authors.initials: M
authors.lastname: Kameno
authors.forename: Takashi
authors.initials: T
authors.lastname: Arai
authors.forename: Yasuyo
authors.initials: Y
authors.lastname: Okumachi
authors.forename: Minoru
authors.initials: M
authors.lastname: Kishi
authors.forename: Katsumi
authors.initials: K
authors.lastname: Yamada
authors.forename: Hisafumi
authors.initials: H
authors.lastname: Yasuda
authors.forename: Kenta
authors.initials: K
authors.lastname: Hara
authors.forename: Koichi
authors.initials: K
authors.lastname: Yokono
authors.forename: Masao
authors.initials: M
authors.lastname: Nagata
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D015551:Autoimmunity / Q000276:immunology; D016022:Case-Control Studies; D002469:Cell Separation; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology* / Q000473:pathology; D018450:Disease Progression; D005260:Female; D006801:Humans; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism*; D007963:Leukocytes, Mononuclear / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D008875:Middle Aged; D013601:T-Lymphocytes / Q000276:immunology* / Q000502:physiology; D055815:Young Adult
chemical_list: D053645:Interleukin-2 Receptor alpha Subunit