Figure 4.

Defective proliferative response and activation of BASH^−/− B cells in vitro. (a) T cell-depleted cells from a spleen of wild-type C57BL/6 mouse, BASH^+/−RAG2^−/− chimera, or admixed two spleens of BASH^−/−RAG2^−/− chimeras were stimulated with the indicated reagents for 48 hr, and the incorporation of [³H]thymidine was measured. Proportion of B cells in the samples was made uniform to10%, as described in Materials and Methods, and that of T cells was <1%. Data are expressed as mean cpm (±SD) of duplicates. *, Separate data from two spleens of BASH^+/−RAG2^−/− chimeras were combined. (b) T cell-depleted spleen cells were stimulated with 10 μg/ml goat anti-IgM for 24 hr, then stained with PE-anti-B220 and FITC-anti-B7-2 mAb (GL-1). B220⁺ cells were gated for the analysis of B7-2 expression.