The number of Tregs increased when co-cultured with DCs and concomitantly treated with resistin. CD4+ T cells or CD4+ CD25- T cells and DCs were co-cultured with 500 ng/ml of resistin for 4 days. The cells were then incubated with anti-human CD2 and CD3 antibodies for an additional 3 days. (A) At the end of the incubation period, total RNA was isolated and subjected to RT-PCR to measure mRNA expression of CTLA-4, FoxP3 and TGF-β. (B) After the staining of the cells with anti-human CD25-APC and -FoxP3-PE antibodies, CD25+FoxP3+ Tregs were analyzed by flow cytometry. (C) After the staining with anti-human CD25-APC antibody, CD25+ T cells were isolated using anti-APC magnetic beads. The isolated CD25+ T cells and CD4+ CD25- naïve T cells labeled with CFSE were co-cultured with DCs and stimulated with anti-human CD2 and CD3 antibodies for 5 days. Cell proliferation was measured by flow cytometry. The value in each panel indicates the percentage of CD25+ FoxP3+ Tregs.