Bim ablation partially rescues GC- and NP-specific IgG1⁺ B cells in Dicer1^fl/flAicda^Cre/+ mice. (A) Flow cytometric analysis of Bim protein levels in splenic GC and non-GC B cells from Dicer1^+/+Aicda^Cre/+ and Dicer1^fl/flAicda^Cre/+ mice 10 days after immunization with NP₃₈-CGG. Dump⁻CD19⁺Fas⁺NIP⁺ cells from Dicer1^+/+Aicda^Cre/+ (red), Dicer1^fl/flAicda^Cre/+ (blue), and Dicer1^+/+Aicda^Cre/+Bim^−/− (gray) mice were fixed, permeabilized, and stained intracellularly with an anti–Bim antibody. (B) Flow cytometric analysis of GC B cells and NP-specific IgG1 cells in the spleens of Dicer1^+/+Aicda^Cre/+Bim^+/+ (WT), Dicer1^fl/flAicda^Cre/+Bim^+/+ (KO), and Dicer1^fl/flAicda^Cre/+Bim^−/− (DKO) mice at day 10 after immunization with NP₃₈-CGG as described in Figure 3. Numbers adjacent to the outlined areas indicate the percentage of cells in the individual gate. (C) Frequency of CD19⁺Fas⁺PNA⁺ (top panel) and NIP⁺IgG1⁺ (bottom panel) cells among total B cells in the spleens of WT (●), KO (■), and DKO (♦) mice at day 10 after immunization. Each symbol represents one mouse. (D) Confocal microscopy of spleen sections of WT, KO, and DKO mice 10 days after immunization with NP₃₈-CGG as described in Figure 3B. (E-F) ELISPOT assays of anti–NP IgG1 ASCs cells in spleens (E) and bone marrow (F) of day 12 postimmunized WT, KO, and DKO mice using BSA-NP₁₇ (top panel) or BSA-NP₂ (bottom panel) as coating antigens. (G-H) Frequency of anti-NP₁₇ (green symbol) and anti-NP₂ (red symbol) IgG1 ASCs in spleens (G) and bone marrow (H) of WT (circles), KO (squares), and DKO (diamonds) mice at day 12 after immunization. Each symbol represents 1 mouse. Data are representative of 3 independent experiments (A,D) or 5 independent experiments (B,E-F).