Fig. 5: Cfp1 deletion promotes differentiation of GCB into plasma cells.

Mice were immunized with NP-KLH/MnJ, boosted on day 8 and analyzed on day 14. A Intracellular staining (red and yellow: Cfp1^fl/fl; blue: Cfp1^fl/fl Aicda^Cre) and gMFI of IRF4 in control and Cfp1^fl/flAicda^Cre GCB cells in the spleen. Data were pooled from two independent experiments; n = 7; 3 m, 4 f. FMO, Fluorescence Minus One. B Genomebrowser view of the Irf4 mRNA, H3K4me3 and CFP1 occupancy (red and purple: Cfp1^fl/fl; blue: Cfp1^fl/fl Aicda^Cre) in control and Cfp1-deficient GCB cells. C Ratio of CD138⁺ cells over GCB (IgD^-B220⁺CD95⁺GL7⁺) cells in the spleen of control and Cfp1-deficient mice. Data were pooled from three independent experiments; Cfp1^fl/fl (n = 7; 3 m, 4 f); Cfp1^fl/fl Aicda^Cre (n = 8; 4 m, 4 f). D Ratio and absolute numbers of plasma cells (IgD^-CD138⁺) over total splenic B cells. Data were pooled from five independent experiments; Cfp1^fl/fl (n = 15; 6 m, 9 f); Cfp1^fl/fl Aicda^Cre (n = 17; 8 m, 9 f). E Representative flow cytometry (orange: IRF4⁺; red: BCL6⁺; grey: IRF4^-BCL6^-) to identify PC precursors (BCL6^lo IRF4⁺ CD69⁺) in LZ GCB (B220⁺IgD^-GL7⁺CD38^-CD86^hiCXCR4^lo). Data were pooled from two independent experiments; Cfp1^fl/fl (n = 5; 2 m, 3 f); Cfp1^fl/fl Aicda^Cre (n = 4; 2 m, 2 f). p < 0.0001 (= 9.16e–5). F Schematic illustration of in vitro iGCB induction and plasma cell differentiation with the 40LB culture system. G Flow cytometry plots and ratio of CD138⁺ PC on 40LB cultures supplemented with IL-4 and subsequent IL-21 for 3 additional days. Data were pooled from two independent experiments; n = 5; 1 m, 4 f. p < 0.0001 (= 3.64e–7). H Intracellular staining and gMFI (red: Cfp1^fl/fl; blue: Cfp1^fl/flCd21^Cre) of IRF4 in control and Cfp1^fl/flCd21^Cre iGCB cells. Data were pooled from two independent experiments; n = 5; 1 m, 4 f. A–H Each symbol indicates one mouse and lines denote means. P-values by unpaired t-test (two-tail).