Imbalance in distribution of functional autologous regulatory T cells in rheumatoid arthritis.
OBJECTIVE
Regulatory T cells (Tregs) exert their anti-inflammatory activity predominantly by cell contact-dependent mechanisms. A study was undertaken to investigate the regulatory capacity of autologous peripheral blood Tregs in contact with synovial tissue cell cultures, and to evaluate their presence in peripheral blood, synovial tissue and synovial fluid of patients with rheumatoid arthritis (RA).


METHODS
44 patients with RA and 5 with osteoarthritis were included in the study. The frequency of interferon (IFN)gamma-secreting cells was quantified in synovial tissue cell cultures, CD3-depleted synovial tissue cell cultures, synovial tissue cultures co-cultured with autologous CD4+ and with CD4+CD25+ peripheral blood T cells by ELISPOT. Total CD3+, Th1 polarised and Tregs were quantified by real-time PCR for CD3epsilon, T-bet and FoxP3 mRNA, and by immunohistochemistry for FoxP3 protein.


RESULTS
RA synovial tissue cell cultures exhibited spontaneous expression of IFNgamma which was abrogated by depletion of CD3+ T cells and specifically reduced by co-culture with autologous peripheral blood Treg. The presence of Treg in RA synovitis was indicated by FoxP3 mRNA expression and confirmed by immunohistochemistry. The amount of FoxP3 transcripts, however, was lower in the synovial membrane than in peripheral blood or synovial fluid. The T-bet/FoxP3 ratio correlated with both a higher grade of synovial tissue lymphocyte infiltration and higher disease activity.


CONCLUSIONS
This study has shown, for the first time in human RA, the efficacy of autologous Tregs in reducing the inflammatory activity of synovial tissue cell cultures ex vivo, while in the synovium FoxP3+ Tregs of patients with RA are reduced compared with peripheral blood and synovial fluid. This local imbalance of Th1 and Treg may be responsible for repeated rheumatic flares and thus will be of interest as a target for future treatments.
Behrens
Frank
F
pharmazentrum frankfurt, ZAFES Clinic of Goethe University, Frankfurt, Germany.
Himsel
Andrea
A
Rehart
Stefan
S
Stanczyk
Joanna
J
Beutel
Björn
B
Zimmermann
Stefanie Y
SY
Koehl
Ulrike
U
Möller
Burkhard
B
Gay
Steffen
S
Kaltwasser
Joachim P
JP
Pfeilschifter
Josef M
JM
Radeke
Heinfried H
HH
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000276:immunology*; D015415:Biomarkers / Q000032:analysis; D017252:CD3 Complex / Q000235:genetics / Q000276:immunology; D002478:Cells, Cultured; D005260:Female; D051858:Forkhead Transcription Factors / Q000032:analysis / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D007371:Interferon-gamma / Q000276:immunology; D016753:Interleukin-10 / Q000276:immunology; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000276:immunology; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013583:Synovial Membrane / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology; D016212:Transforming Growth Factor beta / Q000276:immunology
D015415:Biomarkers; D017252:CD3 Complex; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D016753:Interleukin-10; D007371:Interferon-gamma