Altered frequency and migration capacity of CD4+CD25+ regulatory T cells in systemic lupus erythematosus

Objectives. To determine the frequency and chemokine receptor-related migratory capacity of CD4(+)CD25(+) regulatory T cells (Tregs) and their association with clinical parameters in patients with SLE. Methods. The expression of CD4, CD25, FoxP3 and CCR4 was examined with flow cytometry after staining with fluorescence-conjugated antibodies in 20 patients with SLE, 20 patients with RA and 21 age- and sex-matched healthy controls. For analysis of migration capacity in 24-well chemotaxis chambers, sorted cells were stimulated with ligands of CCR4, CCL17 and CCL22 and analysed with FACScan. Correlations between the number of Tregs and CCR4(+) Treg cells and clinical parameters were analysed. Results. The numbers of Tregs(bright) and CCR4(+) Tregs(bright) were significantly decreased in the patients with SLE compared with healthy controls. The number of Tregs(bright) was negatively correlated with the levels of anti-dsDNA antibody and the number of CCR4(+) Tregs(bright) had a positive correlation with the levels of C-3. Percentage of migrated Tregs(bright) by CCL17 or CCL22 was significantly decreased in the patients with SLE compared with healthy controls. Conclusions. These results suggest that altered frequency of Tregs and CCR4(+) Tregs(bright) and decreased migratory capacity of Tregs might be involved in the pathogenesis of SLE and indicate that targeting the Tregs can be a new therapeutic strategy in SLE.