Figure 4.

Inhibition of TALL-1-triggered B cell costimulation by sBCMA. Purified B lymphocytes cultured in 96-well dishes were treated for 40 h with the following reagents: (i) TBS control buffer, (ii) Flag-sTALL-1 (100 ng/ml), (iii) anti-IgM (10 μg/ml), (iv) Flag-sTALL-1 (100 ng/ml) + anti-IgM (10 μg/ml), (v) Flag-sTALL-1 (100 ng/ml) + anti-IgM (10 μg/ml) + concentrated Flag-sBCMA-Fc (5 μl), and (vi) Flag-sTALL-1 (100 ng/ml) + anti-IgM (10 μg/ml) + concentrated Flag-Fc (5 μl). The treated cells were pulsed with [³H]thymidine for 10 h. [³H]Thymidine incorporation was measured by liquid scintillation counting.