Figure 2.

Proliferation and viability following low CD70 and CD154 interaction. B lymphocytes were monitored following their stimulation with CD70 and CD154 as well as for their response to the mock L929 cell line using a low ratio (1 : 20) for all support cells. (a) Proliferation and (b) viability were measured on days 4, 8, and 11. The time laps between days 0 and 4 are the transition phase and differentiation phase was started on day 4 and lasted until day 11. (c) Secretion of IgG and IgA was measured by ELISA assay with the pooled supernatant harvested on days 6, 8, and 11. (d) At the end of the differentiation phase (day 11), B lymphocytes were analyzed using flow cytometry to evaluate the frequency of CD38⁺ cells and CD38⁺CD138⁺ cells. These results are representative of 5 independent experiments. All errors bars stand for SD and can be smaller than symbols.