FIGURE 6.

The B cell receptor induced calcium flux in DT40 cells is blocked by Sp-cAMPS in a SHIP-dependent manner. The upper panel shows experiments performed using wild type DT40 cells (A), and the lower panel shows experiments with DT40 cells with harboring a targeted disruption of SHIP1 expression (SHIP-deficient) (B). The level of intracellular Ca²⁺ was measured in DT40 cells under four conditions: DT40 cells stimulated by cross-linking the B cell receptor alone (BCR, closed black circles); DT40 cells pretreated with Sp-cAMPS for 15 min and then stimulated by cross-linking the B cell receptor alone (Sp-cAMPS+BCR, closed red triangles); DT40 cells in which both the BCR and FcR were cross-linked (BCR+FcR, blue closed squares); and DT40 cells pretreated with Sp-cAMPS for 15 min in which both the BCR and FcR were cross-linked (Sp-cAMPS+BCR+FcR, open green circles). WT, wild type.