Chemokine and chemokine receptor expression in paired peripheral blood mononuclear cells and synovial tissue of patients with rheumatoid arthritis, osteoarthritis, and reactive arthritis
- Division of Clinical Immunology and Rheumatology, Academic Medical Centre/University of Amsterdam, The Netherlands
- Correspondence to:
Professor P P Tak
Division of Clinical Immunology and Rheumatology F4-218, Department of Internal Medicine, Academic Medical Centre/University of Amsterdam, Meibergdreef 9, NL-1105 AZ Amsterdam, The Netherlands;
- Accepted 31 July 2005
- Published Online First 17 August 2005
Background: Chemokine receptors and chemokines have a crucial role in leucocyte recruitment into inflamed tissue.
Objective: To examine the expression of an extensive number of chemokines and receptors in a unique bank of paired samples of synovial tissue (ST) and peripheral blood (PB) from patients with different forms of arthritis to assist in identifying suitable targets for therapeutic intervention.
Methods: Synovial biopsy specimens were obtained from 23 patients with rheumatoid arthritis (RA), 16 with osteoarthritis, and 8 with reactive arthritis. ST chemokine (CCL2/MCP-1, CCL5/RANTES, CCL7/MCP-3, CCL8/MCP-2, CCL14/HCC-1, CCL15/HCC-2, CCL16/HCC-4), chemokine receptor (CCR1, CCR2b, CCR5, CXCR4), and CD13 expression was analysed by immunohistochemistry and two colour immunofluorescence. Chemokine receptor expression (CCR1, CCR3, CCR5, CCR6, CCR7) on PB cells was studied by flow cytometry. Non-parametric tests were used for statistical analysis.
Results: Abundant expression of CCR1, CXCR4, and CCR5 was found in all forms of arthritis, with a specific increase of CCL5 and CCL15 in RA. CCL7, CCL8, CCL14, CCL15, and CCL16 were detected for the first time in ST. The results for PB analysis were comparable among different arthritides. Interestingly, compared with healthy controls, significantly lower expression of CCR1 (p<0.005) and CCR5 (p<0.05) by PB monocytes in the patient groups was seen.
Discussion: A variety of chemokines and receptors might have an important role in several inflammatory joint disorders. Although other receptors are involved as well, migration of CCR1+ and CCR5+ cells towards the synovial compartment may play a part in the effector phase of various forms of arthritis.
- APC, allophycocyanin
- DMEM, Dulbecco’s modified Eagle’s medium
- FCS, fetal calf serum
- FITC, fluorescein isothiocyanate
- FLS, fibroblast-like synoviocytes
- HRP, horseradish peroxidase
- mAb, monoclonal antibody
- OA, osteoarthritis
- PB, peripheral blood
- PBMCs, peripheral blood mononuclear cells
- PBS, phosphate buffered saline
- PE, phycoerythrin
- RA, rheumatoid arthritis
- ReA, reactive arthritis
- RT, room temperature
- ST, synovial tissue
Published Online First 17 August 2005
Competing interests: None.
JJH contributed to the experiments and was responsible for data analysis and interpretation and wrote the manuscript.
TJMS and PRB were responsible for both the set up and performance of the experiments.
PPT was responsible for the planning of the work and contributed to data analysis, interpretation, and writing up.