In vitro effects of meloxicam on the number, Foxp3 expression, production of selected cytokines, and apoptosis of bovine CD25+CD4+ and CD25-CD4+ cells

The purpose of this study was to evaluate the effect of meloxicam (MEL) on selected immune parameters of bovine CD25highCD4+, CD25lowCD4+, and CD25-CD4+ cells. Peripheral blood mononuclear cells (PBMCs) collected from 12-month-old heifers were treated with MEL at a concentration corresponding to the serum level of this medication following administration at the recommended dose (MEL 5 x 10(-6) M) and at a concentration 10 times lower (MEL 5 x 10(-7) M). After 12 and 24 h of incubation with the drug, the percentage of CD25highCD4+ cells decreased; however, this disturbance was quickly reversed. Furthermore, the absolute number of CD25highCD4+ cells in the PBMC populations treated with MEL 5 x 10(-6) M for 48 and 168 h was increased. Prolonged (168 h) exposure to the drug increased the percentage of Foxp3+ cells in the CD25highCD4+ cell subpopulation. The higher dose of MEL was found to significantly increase the percentage of IFN-gamma+ cells among the CD25-CD4+ cells. These results indicated that MEL does not exert an immunosuppressive effect by depleting CD4+ cells and suppression of IFN-gamma+ production by these cells. Furthermore, IL-10 and TGF-beta production was not changed following exposure to MEL.

Subpopulations of Regulatory T Cells in Rheumatoid Arthritis, Systemic Lupus Erythematosus, and Behcet's Disease

Recently, subpopulations of regulatory T (Treg) cells, resting Treg (rTreg) and activated Treg (aTreg), have been discovered. The authors investigated the relationship between the change of Treg, aTreg and rTreg and autoimmune diseases. Treg cells and those subpopulations were analyzed by using the human regulatory T cell staining kit and CD45RA surface marker for 42 rheumatoid arthritis (RA), 13 systemic lupus sclerosis (SLE), 7 Behcet's disease (BD), and 22 healthy controls. The proportion of Treg cells was significantly lower in RA (3.8% +/- 1.0%) (P < 0.001) and BD (3.3% +/- 0.5%) (P < 0.01) compared to healthy controls (5.0% +/- 1.3%). The proportion of aTreg cells was also significantly lower in RA (0.4% +/- 0.2%) (P = 0.008) and BD (0.3% +/- 0.1%) (P = 0.013) compared to healthy controls (0.6% +/- 0.3%). The rTreg cells showed no significant differences. The ratio of aTreg to rTreg was lower in RA patients (0.4% +/- 0.2%) than that in healthy controls (0.7% +/- 0.4%) (P = 0.002). This study suggests that the decrement of aTreg not rTreg cells contributes the decrement of total Treg cells in peripheral blood of RA and BD autoimmune diseases. Detailed analysis of Treg subpopulations would be more informative than total Treg cells in investigating mechanism of autoimmune disease.

CD4+CD25highFoxP3+ Regulatory T-cells in Hematologic Diseases / 대한진단검사의학회지

BACKGROUND: CD4+CD25+ regulatory T-cells (Tregs) play a critical role in immune responses. We explored the status of Tregs in neoplastic and autoimmune hematologic diseases. We also evaluated the technical aspects of Treg measurement in terms of sample type and detection markers. METHODS: A total of 68 subjects were enrolled: 11 with AML, 8 with MDS, 10 with autoimmune diseases, and 39 controls. Tregs were analyzed in peripheral blood (PB) and bone marrow (BM) samples from each subject. Flow cytometry and the Human Regulatory T cell Staining Kit (eBioscience, USA) for CD4, CD25, and FoxP3 (forkhead box P3) were used. RESULTS: The CD4+CD25high/CD4 and CD4+CD25highFoxP3+/CD4 populations were significantly correlated (P<0.0001). The AML and high-risk MDS groups had significantly larger CD4+CD25high/CD4 and CD4+CD25highFoxP3+/CD4 populations in PB than the autoimmune (P=0.007 and 0.012, respectively) and control groups (P=0.004 and 0.006, respectively). Comparable findings were observed in BM. The CD4+CD25highFoxP3+/CD4 population was significantly larger in PB than in BM (P=0.0003). CONCLUSIONS: This study provides comparison data for Tregs in AML, MDS, and autoimmune hematologic diseases, and would be helpful for understanding the different immunologic bases of various hematologic diseases. Treg measurement using CD4, CD25, and/or FoxP3 in PB rather than in BM seems to be practical for routine hematologic purposes. Large-scale analysis of the diagnostic role of Treg measurement is needed.

Maintenance of CD8+T-cell anergy by CD4+CD25+ regulatory T cells in chronic graft-versus-host disease

In a murine model of systemic lupus erythematosus (SLE)-like chronic graft-versus-host disease (cGVHD), donor CD8+T cells rapidly fall into anergy to host cells, while donor CD4+T cells hyperactivate B cells and break B-cell tolerance to self-Ags in the recipient mouse. The functional recovery of donor CD8+T cells can result in the conversion of cGVHD to acute GVHD (aGVHD), indicating that donor CD8+T-cell anergy is a restriction factor in the development of cGVHD. In this report, we present evidence that donor CD4+CD25+regulatory T cells (T(reg) cells) are critical in maintaining the donor CD8+T-cell anergy and thus suppressing the development of aGVHD in mice that are naturally prone to cGVHD. Our results provide a novel insight into the role of T(reg) cells in determining cGVHD versus aGVHD.