Function of regulatory T-cells improved by dexamethasone in Graves' disease.
OBJECTIVE
Intrathyroid injection of dexamethasone (DEX) has been used to treat Graves' disease (GD); however, the mechanism of this treatment remains poorly understood. The objective of this study was to investigate the effects of DEX on the function of regulatory T (Treg) cells (CD4(+)CD25(+)T cells) in patients with GD.


METHODS
Peripheral blood was obtained from 20 patients with GD, and peripheral blood mononuclear cells (PBMCs) were isolated by Ficoll-Hypaque density gradient separation. CD4(+)CD25(-)/CD4(+)CD25(+)T cells were isolated by immunomagnetic selection and DEX was co-cultured with PBMCs or isolated T-cells for 72 h. Treg cell function was analyzed using the proliferation rate of CD4(+)CD25(-)T cells.


RESULTS
The proportion of Treg cells and the transcription factor forkhead box P3 (FOXP3) mRNA expression in PBMCs decreased in GD patients compared with healthy subjects, and Treg cell function was impaired in patients with GD. Although the proportion of Treg cells and FOXP3 mRNA expression in PBMCs did not increase, the function of Treg cells improved after the treatment with DEX. Moreover, the proportion of T-helper 2 (Th2) cells was decreased by the DEX treatment.


CONCLUSIONS
DEX could effectively improve the function of Treg cells and set up a new balance of Th1/Th2 in GD patients. This study might help to further understand the immune mechanism of the intrathyroid injection of DEX in the treatment of GD and facilitate the potential use of this therapy.
Department of Endocrinology, Department of Rehabilitation Central Laboratory, Nanjing First Hospital Affiliated to Nanjing Medical University, 68 Changle Street, Nanjing, China.
Yun
Y
Hu
Wei
W
Tian
Ling-Ling
LL
Zhang
Hao
H
Liu
Guo-Ping
GP
Yin
Bang-Shun
BS
He
Xiao-Ming
XM
Mao
D000328:Adult; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000473:pathology; D016022:Case-Control Studies; D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology* / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism; D006111:Graves Disease / Q000097:blood / Q000188:drug therapy* / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology / Q000627:therapeutic use; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D008297:Male; D061251:Primary Cell Culture; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology
C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D007166:Immunosuppressive Agents; D003907:Dexamethasone