FIGURE 6.
Glioma-derived Tregs suppress tumor-specific CD8+ T cells. CD4+CD25high Tregs were sorted out from glioma-derived CD4+ T cells using the FACSVantage system and the generated Tregs. CD8+ T cells were isolated from blood collected from the surgical operative field of the patients with glioma and were labeled with carboxyfluorescein succinimidyl ester in the presence of DCs and glioma-extracted proteins (1 μg/ml; containing the tumor antigens using to activate tumor-specific Tregs and tumor-specific CD8+ T cells) (A). Two other groups of cells were also cultured with glioma-derived Tregs (B) or generated Tregs (C) (CD8+ T cell/Treg/DC = 105:105:104/well). Cells were collected 4 days later and analyzed by flow cytometry. A–C, histograms show CD8+ T cell proliferation. D, CD8+ T cells were cultured with DCs and BSA. E, scatter dot plots show the levels of granzyme B in the culture medium. Each dot represents a single data point. Data represent six experiments.