Figure 4.
SphK1 inhibitors suppress mouse B-cell isotype switching ex vivo. Splenic B cells from C57BL/6 mice were isolated by negative selection using anti-CD43 beads by MACS sorting. B cells were cultured with agonistic anti-CD40 antibody and IL-4 for 8 d (A, B) or 3 d (C, D) in the presence of the indicated concentrations of SK1-I (A, C) or PF543 (B, D). A, B) Antibody levels were measured by ELISA. C, D) DNA synthesis was measured by [3H]thymidine uptake. Data are expressed as means ± sd from triplicate determinations. Similar results were obtained in 2 additional experiments. *P < 0.05.