Glucocorticoid therapy of antigen-induced arthritis depends on the dimerized glucocorticoid receptor in T cells

• Published in: Proceedings of the National Academy of Sciences - PNAS 2011-11, Vol.108 (48), p.19317-19322
• Main Authors: Baschant, Ulrike, Frappart, Lucien, Rauchhaus, Una, Bruns, Lisa, Reichardt, Holger M, Kamradt, Thomas, Bräuer, Rolf, Tuckermann, Jan P
• Format: Article
• Language: English
• Subjects: adverse effects; Animals; anti-inflammatory activity; Antiinflammatories; Arthritis; Arthritis, Rheumatoid - chemically induced; Arthritis, Rheumatoid - drug therapy; Biological Sciences; cytokines; Cytokines - blood; Dimerization; DNA; Drug therapy; Flow Cytometry; Fluorescein-5-isothiocyanate; Freund's Adjuvant - toxicity; gamma -Interferon; Glucocorticoid receptors; Glucocorticoids; Glucocorticoids - metabolism; Glucocorticoids - therapeutic use; Glucose-6-Phosphate Isomerase - toxicity; Helper cells; humans; Inflammation; Interferon-gamma - metabolism; Interleukin-17 - genetics; Interleukin-17 - metabolism; Joints - pathology; Knee joint; Lymphocytes T; Mice; Mice, Inbred BALB C; Mice, Transgenic; Myeloid cells; Real-Time Polymerase Chain Reaction; Receptors, Glucocorticoid - chemistry; Receptors, Glucocorticoid - metabolism; Rheumatoid arthritis; Rodents; Serum Albumin, Bovine - toxicity; Side effects; Steroid hormones; Steroids; Swelling; T cell receptors; T lymphocytes; T-Lymphocytes - metabolism; Therapeutic applications; therapeutics; Transcription; transcription (genetics)
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1105857108

Despite several side effects, glucocorticoids (GCs) have been widely used for 60 y to treat rheumatoid arthritis on the basis of their antiinflammatory effects. However, the cells targeted by GCs and the transcriptional mechanisms underlying their actions through the glucocorticoid receptor (GR) in steroid therapy remain poorly defined. Using cell type-specific GR-deficient mice subjected to antigen-induced arthritis (AIA) as a model of human rheumatoid arthritis, we show that GC action on T cells but not myeloid cells is critical for therapeutic intervention in AIA. Furthermore, the resistance of mice expressing a DNA binding-defective GR (GRdim) to GC treatment reveals that dimerization of the GR is indispensable for the antiinflammatory effects. In these mice, the GC-induced suppression of TH1 and TH17 cell-derived proinflammatory cytokines is impaired. Our finding that IL-17A–/– mice are resistant to GC therapy, whereas IFN-γ–/– mice respond as efficiently as WT mice implies that IL-17–producing T cells and not IFN-γ–producing T cells are the most important targets for an efficient GC therapy. The present study's identification of the critical cell type and the mode of GR action in steroid therapy of AIA significantly advances our understanding of steroid therapy and should lead to therapies with greater efficiency and fewer side effects.