CD4+ CD25+ T cells with the phenotypic and functional characteristics of regulatory T cells are enriched in the synovial fluid of patients with rheumatoid arthritis

• Published in: Clinical and experimental immunology Vol. 140; no. 2; pp. 360 - 367
• Main Authors: Möttönen, M., Heikkinen, J., Mustonen, L., Isomäki, P., Luukkainen, R., Lassila, O.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.05.2005; Blackwell Science Inc
• Subjects: Adult; Aged; Aged, 80 and over; Arthritis, Rheumatoid - immunology; CD4-Positive T-Lymphocytes - immunology; Cell Proliferation; Cells, Cultured; Clinical Studies; DNA-Binding Proteins - metabolism; Female; Forkhead Transcription Factors; human; Humans; Immune Tolerance; Immunophenotyping; Lymphocyte Activation - immunology; Male; Middle Aged; Receptors, Interleukin-2 - analysis; regulatory T cells; rheumatoid arthritis; Synovial Fluid - immunology; T-Lymphocyte Subsets - immunology
• ISSN: 0009-9104; 1365-2249
• DOI: 10.1111/j.1365-2249.2005.02754.x

Summary CD4+ CD25+ regulatory T (Treg) cells play a critical role in the maintenance of peripheral tolerance and the prevention of autoimmunity. In the present study, we have explored the characteristics of CD4+ CD25+ Treg cells in patients with rheumatoid arthritis (RA). The frequency and phenotype of CD4+ CD25+ T cells in paired samples of synovial fluid (SF) and peripheral blood (PB) from patients with RA and PB from normal controls were analysed. An increased frequency of CD4+ cells T cells expressing CD25 was detected in SF compared to PB from patients with RA. No significant difference was observed in the numbers of CD4+ CD25+ T cells in PB from patients and controls. SF CD4+ CD25+ T cells expressed high levels of CTLA‐4 (both surface and intracellular), GITR and OX40, as well as Foxp3 transcripts. Functionally, SF CD4+ CD25+ T cells were impaired in their proliferative responses and could suppress the proliferation of their CD4+ CD25– counterparts. In conclusion, these data demonstrate that CD4+ CD25+ Treg cells, with the potential to regulate the function of effector T cells and antigen‐presenting cells, accumulate in the synovium of patients with RA.