Figure 2.

CTL, but not Th cells, rapidly up-regulate CD70 on activation. Negatively selected CD8 and CD4 cells (5 × 10⁵) were stimulated with SAG (0.1 ng/ml staphylococcal enterotoxin A, 0.1 ng/ml staphylococcal enterotoxin B, and 0.1 ng/ml toxic shock syndrome toxin 1) in the presence of autologous DC (10⁵). After the indicated times, three-color flow cytometry analysis was performed by using fluorochrome-conjugated Ab with specificities for CD70 (fluorescein isothiocyanate), CD27 (phycoerythrin), and CD3 (APC). Gates were set on CD3⁺ lymphocytes. Data are representative for two independent assays.