Recent animal studies have shown that CD4 þ CD25þ T cells play a crucial role in the suppression of the immune response and that depletion of this subset of T cells might lead to development of autoimmune diseases. The aim of the present study was to investigate the levels of CD4 þ CD25 þ T cells in the peripheral blood of patients with systemic lupus erythematosus (SLE). Ninety-four SLE patients, 52 patients with rheumatoid arthritis (RA) and 50 age-and gendermatched healthy individuals were enrolled in the study. A flowcytometric method was applied in the measurement of CD4 þ CD25 þ T cells. The results showed that patients with SLE had statistically lower levels of CD4 þ CD25 þ T cells than did normal controls, when expressed as either percentages of peripheral blood mononuclear cells (PBMCs) (mean AE SD, 8.49 AE 6.36 versus 11.11 AE 4.58%, P < 0.05) or absolute cell numbers (98.77 AE 97.52 versus 213.93 AE 104.52 cells/mm 3 , P < 0.05). In terms of CD25 bright CD4 þ T cells, defined as having a fluorescence intensity of CD25 expression exceeding 100, SLE patients still had significantly lower levels than did normal controls expressed as percentages of PBMCs (1.76 AE 1.32 versus 3.73 AE 1.30%, P < 0.05). No significant differences could be found between RA patients and normal controls. The overwhelming majority of CD4 þ CD25 þ T cells belonged to CD45RO þ cells and most did not express the CD69 molecule. Although decreased CD4þ CD25 þ T cells were found in SLE patients, we failed to find a significant correlation between the levels of CD4 þ CD25 þ T cells and disease activities of SLE. To the best of our knowledge, this is the first study to demonstrate that patients with SLE had decreased CD4 þ CD25 þ T cells. However, the exact role of the decreased CD4 þ CD25þ T cells in the pathogenesis of SLE remains to be elucidated.

Objective. MicroRNA (miRNA) plays a role in autoimmune diseases. MiRNA-223 (miR-223) is upregulated in patients with rheumatoid arthritis (RA) and is involved in osteoclastogenesis, which contributes to erosive disease. The aim of this study was to test the feasibility of using lentiviral vectors expressing the miR-223 target sequence (miR-223T) to suppress miR-223 activity as a therapeutic strategy in a mouse model of collagen-induced arthritis (CIA).Methods. Levels of miR-223 in the synovial tissue of patients with RA or osteoarthritis (OA), as well as in the ankle joints of mice with CIA, were determined by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). Lentiviral vectors expressing miR-223T (LVmiR-223T) or luciferase short hairpin RNA (LVshLuc) as a control vector were injected intraperitoneally into mice with CIA. Treatment responses and disease-related bone mineral density were monitored. Levels of nuclear factor 1A (NF-1A), a direct target of miR-223, and macrophage colony-stimulating factor receptor (M-CSFR), which is critical for osteoclastogenesis, were measured by immunohistochemistry and quantitative RT-PCR. Osteoclasts were assessed by tartrate-resistant acid phosphatase staining.Results. MiR-223 expression was significantly higher in the synovium of RA patients and in the ankle joints of mice with CIA as compared to OA patients and normal mice. LVmiR-223T treatment reduced the arthritis score, histologic score, miR-223 expression, osteoclastogenesis, and bone erosion in mice with CIA. Down-regulation of miR-223 with concomitant increases in NF-1A levels and decreases in M-CSFR levels was detected in the synovium of LVmiR-223T-treated mice.Conclusion. This study is the first to demonstrate that lentivirus-mediated silencing of miR-223 can reduce disease severity of experimental arthritis. Furthermore, our results indicate that inhibition of miR-223 activity should be further explored as a therapeutic strategy in RA.

A soluble form of cytotoxic T-lymphocyte-associated antigen-4 (sCTLA-4) was recently found and shown to possess a downregulatory function as a membranebound CTLA-4 molecule. The purpose of the study was to investigate the expression of sCTLA-4 molecule in patients with systemic lupus erythematosus (SLE). One hundred patients with SLE and 40 age-and sex-matched healthy individuals were enrolled in the study. The results showed that patients with SLE have significantly higher levels of sCTLA-4 in sera than healthy controls (21.6 AE 12.3 ng/ml versus 5.9 AE 5.4 ng/ml, P < 0.001). Increased expression of sCTLA-4 mRNA in peripheral blood mononuclear cells (PBMCs) was also found in SLE patients. However, we could not find a statistically significant correlation between the serum levels of sCTLA-4 and lupus disease activities. The reported CTLA-4 gene polymorphism in promoter region at position À318 did not affect the levels of sCTLA-4. To the best of our knowledge, this is the first report showing that patients with SLE have increased sCTLA-4 expression. However, the mechanism and role of increased sCTLA-4 in the pathogenesis of SLE remains elucidated.

CD4þ CD25 þ T cells have been shown to play a regulatory or suppressive role in the immune response and are possibly relevant to the pathogenesis of autoimmune diseases. In the present study, we attempted to investigate the levels of CD4 þ CD25 þ T cells in the peripheral blood (PB) and synovial fluid (SF) of patients with rheumatoid arthritis (RA) and the effects of CD4 þ CD25þ T cells on the in vitro cytokine production by stimulated SF mononuclear cells (SFMC). The results showed that RA patients had similar frequencies of CD4 þ CD25 þ T cells in PB, expressed as a percentages of the lymphocyte population, as did healthy subjects (mean AE SD: 10.52 AE 5.87% versus 11.11 AE 4.58%., respectively). But in contrast to PB, the SF of RA patients contained significantly higher levels of CD4 þ CD25 þ T cells (17.77 AE 7.92% versus 10.52 AE 5.87%, respectively. P < 0.001). When cocultured in vitro with SFMC, CD4 þ CD25þ T cells purified from either PB or SF were found to exert a considerable suppressive effect on the production of cytokines including TNF-a, IFN-g and interleukin-10 (IL-10). The percentages of inhibition of each cytokines ranged from 41.8 to 98.4% (mean, 80.0%) for TNF-a, 42.8 to 98.9% (mean, 83.2%) for IFN-g and 59.3 to 96.6% (mean, 80.0%) for IL-10. Because both pro-inflammatory and anti-inflammatory cytokines were suppressed by CD4 þ CD25 þ T cells, whether CD4 þ CD25 þ T cells might play a beneficial role in the suppression of sustained inflammation in rheumatoid synovium remains to be elucidated.

Objective. The transcription factor Snail is involved in various biologic functions. We hypothesized that this molecule regulates tumor necrosis factor ␣ (TNF␣)-mediated synovial fibroblast activation in the rheumatoid joint. The aim of this study was to examine the role of Snail in the expression of cadherin-11 (Cad-11) and myofibroblast markers, interleukin-6 (IL-6) production, and the invasive ability of cells.Methods. Synovium samples were obtained from patients with rheumatoid arthritis (RA) and from rats with collagen-induced arthritis (CIA). Synovial fibroblasts were treated with TNF␣ or a Wnt signaling inducer, and the joints of rats with CIA were injected with a TNF␣ antagonist. Modulation of Snail expression in the synovial fibroblasts and joints was performed by lentiviral vector-mediated transfer of complementary DNA or short hairpin RNA.Results. The expression of Snail and Cad-11 was higher in synovium and synovial fibroblasts from patients with RA compared with patients with osteoarthritis and was increased in rats with CIA. TNF␣ stimulation or activation of Wnt signaling up-regulated the expression of Snail, Cad-11, and ␣-smooth muscle actin (␣-SMA) in synovial fibroblasts, and anti-TNF␣ therapy down-regulated the expression of Snail, Cad-11, and ␣-SMA in the joints of rats with CIA. Although synovial fibroblast transfectants in which Snail was overexpressed showed increased expression of Cad-11 and ␣-SMA and enhanced TNF␣-mediated invasive capacity and IL-6 production, synovial fibroblast transfectants from rats with CIA in which Snail was silenced showed decreased expression and had the opposite effect on these functions. Normal joints in which Snail was overexpressed had hyperplastic synovium, with increased expression of Cad-11, ␣-SMA, and IL-6. Silencing Snail expression ameliorated arthritis, with reduced Cad-11 expression and reduced levels of extracellular matrix deposition in the joints of rats with CIA, whereas overexpression of Snail exacerbated arthritis, with increased Cad-11 expression and increased levels of extracellular matrix deposition.Conclusion. Our results demonstrate that Snail regulates TNF␣-mediated activation of synovial fibroblasts in the rheumatoid joint. These findings may contribute to the pharmacologic development of therapeutics targeting synovial fibroblasts in patients with RA.