Figure 5. Survivin is required for B cell proliferation, but not survival of activated B cells.

(A) Splenic B cells from survivin^L/Lcd21^Cre and survivin^+/+cd21^Cre mice were cultured in the presence of the indicated stimuli for 3 days. Viability was determined by flow cytometry. The following concentrations were used: 10 ng/mL IL4; 10 ng/mL BAFF, 5 µg/mL anti-CD40, 13 µg/mL anti-IgM F(ab‘)₂ fragments, 10 µg/mL LPS. Statistics were performed using the student’s t-test. (B) Splenic B cells from survivin^L/Lcd21^Cre and survivin^+/+cd21^Cre mice were cultured with the indicated stimuli for 3 days. Graphs show the dilution of the dye eFluro670 as a measure of proliferation. Histograms are representative for 3 independent experiments. (C) Survivin expression in B cells stimulated with LPS (10 µg/mL) plus IL-4 (10 ng/mL) for 3d. (D, E) Splenic B cells from survivin^L/Lcd21^Cre and survivin^+/+cd21^Cre mice were stimulated with anti-CD40 (5 µg/mL) plus IL-4 (10 ng/mL) (D) or LPS (10µg/mL) plus IL-4 (10ng/mL) (E). Plasma cell generation (left) and isotype switching (right) were measured by flow cytometry on day 3 of culture. Results are representative of 3 independent experiments.