Fig 2. 3’RR core enhancers ectopically promote CSR in vivo.

(A) Left: Evaluation of the amount of cells switching at the IgH locus (B220⁺, IgM^neg cells) in spleens from NI or SRBC immunized mutant mice (day 8) Right: Comparison of κ-CSR efficiency as evaluated by counting mCκ⁺ spleen B-cells (gated on B220⁺/GL7⁺ cells) by flow cytometry, in spleens from non-immunized (NI) or SRBC immunized (day 8) mice from KIKS, c3’RR-KIKS and c3’RR-KIKS / Aicda^-/- mice. Percentages +/- SEM are representative of 5 to 13 animals of each genotype (B) Left: Evaluation of the amount of cells switching at the IgH locus (B220⁺, IgM^neg cells) in Peyer’s patches from KIKS, c3’RR-KIKS mice. Middle and right: Comparison of κ-CSR efficiency as evaluated by counting mCκ⁺ spleen B-cells either gated on B220 positive cells (middle) or on B220⁺/GL7⁺(right) by flow cytometry, in Peyer’s patches from KIKS, c3’RR-KIKS and c3’RR-KIKS / Aicda^-/- mice. Percentages +/- SEM are representative of 10 to 25 animals of each genotype. (C) ELISA quantification of serum mκ-LC in NI and SRBC-immunized mice (Day 8). Percentages +/- SEM are representative of 11 to 19 animals of each genotype.