<i>In vitro</i> expansion of CD4⁺CD25⁺ Foxp3⁺ T cells by peptide epitope stimulation.

<p>Splenic lymphocytes were isolated from one NOD mice (total number of mice was 6) and cultured with different peptide epitopes (50 ng/ml) for 7-10 d. Cells were collected and analysed by flow cytometry. (a) The percentages of CD25⁺Foxp3⁺ within CD4⁺cells were presented. (b) Total number of CD4⁺CD25⁺Foxp3⁺ T cells in each group after expansion. Data collected from three independent experiments are shown. (c) Expression of Treg-related phenotypes (CTLA-4, GITR, ICOS, LAG-3) in CD4 T cells from each group. As controls, OVA (50 ng/ml) stimulation could not expand CD4⁺CD25⁺Foxp3⁺ T cells and up-regulate the expression of Treg-related molecules (data not shown). Data are shown as means±SD, n = 5–6 per group. *, <i>P</i><0.05 compared with controls.