Autoreactive T cell response in CD25-negative fraction of peripheral blood mononuclear cells in established type 1 diabetes.
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.
Moriyama
Hiroaki
H
Department of Internal and Geriatric Medicine, Kobe University Graduate School of Medicine, Kobe, Japan. hirom@med.kobe-u.ac.jp
Kotani
Reiko
R
Katsuta
Atsumi
A
Kameno
Mami
M
Arai
Takashi
T
Okumachi
Yasuyo
Y
Kishi
Minoru
M
Yamada
Katsumi
K
Yasuda
Hisafumi
H
Hara
Kenta
K
Yokono
Koichi
K
Nagata
Masao
M
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
D053645:Interleukin-2 Receptor alpha Subunit