DC accumulation and unaltered DC activation in Bim^−/− mice. (A) Total splenocytes of 5-month-old Bim^−/− mice and wild-type controls were counted. Splenocytes were then stained for FITC anti-CD11c, PE anti–PDCA-1, or PE anti-CD11b, and percentage of CD11c⁺ cells was analyzed by flow cytometry. Total numbers of CD11c⁺ cells (left panel) as well as CD11c⁺CD11b⁺ mDCs and CD11c⁺PDCA-1⁺ pDCs (right panel) were quantitated. Data represent mean ± SD of 5 mice of each genotype. Statistical significance between wild-type and Bim^−/− mice was analyzed by Student t test, with P < .001 for total CD11c⁺ DCs, P < .07 for pDCs, and P < .004 for mDCs. (B) Unaltered expression of costimulatory molecules on Bim^−/− DCs. Splenocytes were enriched for DCs by depletion of T and B cells. Cells were then stained with PE anti-CD11c and FITC-conjugated antibodies to CD40, I-A^b, B7.1, B7.2, or ICAM-1 (solid line) or isotype controls (dotted line) and analyzed by flow cytometry. Data shown are representative of 5 mice of each genotype.