In:
The Journal of Clinical Endocrinology & Metabolism, The Endocrine Society, Vol. 91, No. 9 ( 2006-09-01), p. 3639-3646
Abstract:
Context: T regulatory cells have a key role in the pathogenesis of autoimmune diseases in different animal models. However, less information is available regarding these cells in human autoimmune thyroid diseases (AITD). Objective: The objective of the study was to analyze different regulatory T cell subsets in patients with AITD. Design: We studied by flow cytometry and immunohistochemistry different T regulatory cell subsets in peripheral blood mononuclear cells (PBMCs) and thyroid cell infiltrates from 20 patients with AITD. In addition, the function of TREG lymphocytes was assessed by cell proliferation assays. Finally, TGF-β mRNA in thyroid tissue and its in vitro synthesis by thyroid mononuclear cells (TMCs) was determined by RNase protection assay and quantitative PCR. Results: PBMCs from AITD patients showed an increased percent of CD4+ lymphocytes expressing glucocorticoid-induced TNF receptor (GITR), Foxp3, IL-10, TGF-β, and CD69 as well as CD69+CD25bright, CD69+TGF-β, and CD69+IL-10+ cells, compared with controls. TMCs from these patients showed an increased proportion of CD4+GITR+, CD4+CD69+, and CD69+ cells expressing CD25bright, GITR, and Foxp3, compared with autologous PBMCs. Furthermore, a prominent infiltration of thyroid tissue by CD69+, CD25+, and GITR+ cells, with moderate levels of Foxp3+ lymphocytes, was observed. The suppressive function of peripheral blood TREG cells was defective in AITD patients. Finally, increased levels of TGF-β mRNA were found in thyroid tissue, and thyroid cell infiltrates synthesized in vitro significant levels of TGF-β upon stimulation through CD69. Conclusions: Although T regulatory cells are abundant in inflamed thyroid tissue, they are apparently unable, in most cases, to downmodulate the autoimmune response and the tissue damage seen in AITD.
Type of Medium:
Online Resource
ISSN:
0021-972X
,
1945-7197
DOI:
10.1210/jc.2005-2337
Language:
English
Publisher:
The Endocrine Society
Publication Date:
2006
detail.hit.zdb_id:
2026217-6
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