Figure 5

Impaired survival of premalignant splenic B cells upon A1 knockdown. Total spleen cells from mice of the indicated genotypes were incubated in the presence or absence of the indicated mitogens for 24 h. The percentages of viable (Annexin V⁻) CD19⁺B220⁺ B cells in the Venus⁻ or Venus⁺ fractions derived from DT-A1 mice or the total cell fraction of MYC or DT-FF mice (>90% Venus⁺ cells) was assessed by flow cytometry. Representative contour plots of mitogen-treated splenocyte cultures stained with anti-CD19 and anti-B220-specific antibodies and percentages of cells falling within each gate are shown. (b) Quantification of data shown in (a). To assess relative survival, the percentage of viable B cells was compared with the percentage of B cells identified straight after sacrifice. As these percentages differ, the bar graphs show the ratio of the percentage of B220⁺CD19⁺ B cells in culture after 24 h, divided by the percentage of the B220⁺ B cells present in the spleen on the day of sacrifice. All experiments were performed in technical duplicates. Bars represent means±s.e.m. (MYC n=8, DT-FF n=5, DT-A1 n=13, biological replicates, six independent experiments). ANOVA followed by Bonferroni post hoc test. **P⩽0.01, ***P⩽0.001. UN=untreated, CYT=cytokines (IL-2, IL-4 and IL-5), M+CD=anti-IgM and anti-CD40.