PT  - JOURNAL ARTICLE
AU  - Oliver Frey
AU  - Andreas Reichel
AU  - Kerstin Bonhagen
AU  - Lars Morawietz
AU  - Una Rauchhaus
AU  - Thomas Kamradt
TI  - Regulatory T cells control the transition from acute into chronic inflammation in glucose-6-phosphate isomerase-induced arthritis
AID  - 10.1136/ard.2009.123422
DP  - 2010 Aug 01
TA  - Annals of the Rheumatic Diseases
PG  - 1511--1518
VI  - 69
IP  - 8
4099  - http://ard.bmj.com/content/69/8/1511.short
4100  - http://ard.bmj.com/content/69/8/1511.full
SO  - Ann Rheum Dis2010 Aug 01; 69
AB  - Objectives Glucose-6-phosphate isomerase (G6PI)-induced arthritis is a spontaneously remitting experimental arthritis model. It was hypothesised that regulatory T cells (Tregs) are involved in remission and their role in G6PI-induced arthritis was investigated. Methods Tregs were depleted by injection of anti-CD25 before immunisation of DBA/1 mice with G6PI. The severity of arthritis was assessed clinically and histologically and the number and function of G6PI-specific T helper (Th) cells were determined by flow cytometry. Th cells and monocytes/macrophages were depleted using anti-CD4 or clodronate-containing liposomes. Results Injection of anti-CD25 depleted Tregs transiently. Normal numbers of Tregs were restored 5 weeks after G6PI immunisation. Whereas arthritis started to resolve in control mice 3 weeks after immunisation with G6PI, severe arthritis was still present in the anti-CD25-treated mice 12 weeks after immunisation. The most striking ex vivo correlate of non-remitting arthritis was a strong increase in G6PI-specific Th cells 3 days after G6PI immunisation. This difference between treated and control mice declined at later time points. Depletion of CD4 cells ameliorated arthritis in controls but not in anti-CD25-treated mice. In contrast, clodronate-containing liposomes were an effective treatment in both groups. Conclusions Tregs control the transition from acute self-limiting to non-remitting destructive G6PI-induced arthritis already in the preclinical disease stage. Once established, non-remitting destructive arthritis is not controlled by restoration of normal Treg numbers. These findings question the rationale of therapeutic approaches augmenting Treg number or function in established arthritis.