CD38 and CD20 expression by peripheral blood B cells in secondary culture, and CD154 and CD70 expression on activated T cells. (A) Isolated peripheral blood B cells were cultured with IL-2 50 U/mL + IL-10 50 ng/mL + anti-CD40 MoAb 1 μg/mL. At day 3, cells were restimulated with IL-2 + IL-10, IL-2 + IL-10 + anti-CD40 MoAb, or IL-2 + IL-10 + CD70 transfectants. At the end of secondary culture (5 days), flow-cytometric analysis was performed following removal of dead cells by propidium iodide. The results are representative of 4 experiments. (B) CD154 (•) and CD70 (○) expression on E⁺ cells stimulated with PHA at indicated days were analyzed by flow cytometry. Values are the mean ± SD of three experiments using different donors.