FIG. 4.

B-cell activation in vitro. (A) Proliferative responses of B cells. The amount of [³H]thymidine incorporated into the DNA of stimulated purified splenic B cells isolated from 129/Sv control (white bars) and Blk-deficient (black bars) mice is shown. All analyses were done in triplicate. (B) Upregulation of surface CD86 (B7.2). Histograms show the surface expression levels of CD86 (B7.2) on purified splenic B cells isolated from 129/Sv (thin line, light grey area) or Blk-deficient (thick line, dark grey area) mice. Cells were incubated with medium in the absence (filled area) or presence (line) of stimuli.