title: The presence of cytokine-suppressive CD4+CD25+ T cells in the peripheral blood and synovial fluid of patients with rheumatoid arthritis.
abstract: CD4+CD25+ T cells have been shown to play a regulatory or suppressive role in the immune response and are possibly relevant to the pathogenesis of autoimmune diseases. In the present study, we attempted to investigate the levels of CD4+CD25+ T cells in the peripheral blood (PB) and synovial fluid (SF) of patients with rheumatoid arthritis (RA) and the effects of CD4+CD25+ T cells on the in vitro cytokine production by stimulated SF mononuclear cells (SFMC). The results showed that RA patients had similar frequencies of CD4+CD25+ T cells in PB, expressed as a percentages of the lymphocyte population, as did healthy subjects (mean +/- SD: 10.52 +/- 5.87% versus 11.11 +/- 4.58%., respectively). But in contrast to PB, the SF of RA patients contained significantly higher levels of CD4+CD25+ T cells (17.77 +/- 7.92% versus 10.52 +/- 5.87%, respectively. P < 0.001). When cocultured in vitro with SFMC, CD4+CD25+ T cells purified from either PB or SF were found to exert a considerable suppressive effect on the production of cytokines including TNF-alpha, IFN-gamma and interleukin-10 (IL-10). The percentages of inhibition of each cytokines ranged from 41.8 to 98.4% (mean, 80.0%) for TNF-alpha, 42.8 to 98.9% (mean, 83.2%) for IFN-gamma and 59.3 to 96.6% (mean, 80.0%) for IL-10. Because both pro-inflammatory and anti-inflammatory cytokines were suppressed by CD4+CD25+ T cells, whether CD4+CD25+ T cells might play a beneficial role in the suppression of sustained inflammation in rheumatoid synovium remains to be elucidated.
authors.affiliation: Section of Rheumatology and Immunology, Department of Internal Medicine, Medical College, National Cheng Kung University, Tainan, Taiwan, Republic Of China. mfliu@mail.ncku.edu.tw
authors.forename: M-F
authors.initials: MF
authors.lastname: Liu
authors.forename: C-R
authors.initials: CR
authors.lastname: Wang
authors.forename: L-L
authors.initials: LL
authors.lastname: Fung
authors.forename: L-H
authors.initials: LH
authors.lastname: Lin
authors.forename: C-N
authors.initials: CN
authors.lastname: Tsai
mesh_terms: D001172:Arthritis, Rheumatoid / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D016207:Cytokines / Q000097:blood*; D005260:Female; D006801:Humans; D007108:Immune Tolerance; D008297:Male; D015375:Receptors, Interleukin-2 / Q000032:analysis*; D013582:Synovial Fluid / Q000166:cytology / Q000276:immunology*
chemical_list: D016207:Cytokines; D015375:Receptors, Interleukin-2