FIG. 4.

The inhibition of PTK, but not Erk1/2, prevents PorB augmentation of CD86. (A) B cells from C3H/HeJ mice were pretreated for 30 min with a DMSO vehicle (no inhibitor) or genistein, a PTK inhibitor. Cells were then stimulated with medium alone (Med), PorB (10 μg/ml), or anti-IgM (α-IgM; 10 μg/ml) plus CD40L (1:1,000) for 24 h and subjected to flow cytometric analysis using fluorescein isothiocyanate-conjugated rat anti-mouse CD86. (B) In a separate experiment, B cells from C3H/HeJ mice were treated with a DMSO vehicle (no inhibitor) or PD98059, a MEK1/2 inhibitor, and then treated as described in the legend to panel A. Lines correspond to the treatments indicated in panel A.