Figure 2. Phenotype of S-Ag specific T cells detected by intracellular cytokine staining. PBMCs from the active BD patients with a response to S-Ag were cultured with or without mixed S-Ag peptides plus anti-CD28 mAb and then were stained and examined by five color FCM. Lymphocytes were first gated using Forward Scatter (FSC) combined with Side Scatter (SSC), and then the CD3⁺CD8^- and CD3⁺CD8⁺ cells were gated for analyzing the expression of IFN-γ in CD4⁺ T cells and the expression of IFN-γ in CD8⁺ T cells. Lastly, the expressions of CD69 and CD45RO molecules on IFN-γ⁺CD4⁺ and IFN-γ⁺CD8⁺ T cells were analyzed, respectively. A: The charts show the phenotypic feature of S-Ag specific T cells of one representative active BD patient. B: The chart represents the expression of IFN-γ as the percentage of total CD4⁺ or CD8⁺ T cells in six different patients. Data were analyzed by Student’s t-test.