Extended Data Fig. 8: Features of GC B cells of known (time-stamped) or uncertain (non-stamped) stimulation history.
a, Histogram of cell trace violet of naïve cells cultured with anti-IgM stimulations at 0.1 μg/ml (low) and 10 μg/ml (high) for 2 hours. b, Gating strategies for isolating tdTomato+ and tdTomato- LZ GCs of S1PR2-creERT2;Rosa26-Ai14 mice. c, Summary data of Irf4 mRNA expression in tdTomato+ LZ GCs at day 10 and day 21. Data are quantified by normalizing to Actb expression and shown as mean ± s.d. of biological replicates (n=11 per group). P values by two-sided unpaired t tests. d, Summary data of IRF4 protein levels in tdTomato+ and tdTomato- LZ GCs at day 21. Data pooled from 2 independent experiments. Each symbol indicates one mouse (n=8). P values by two-sided paired t tests. e-f, Bach2 (e) and Prdm1 (f) mRNA expression by qPCR. Data are quantified by normalizing to Actb expression and shown as mean ± s.d. of biological replicates (n=11 per group). P values by two-sided unpaired t tests. g-i, Violin plots showing log2 of fold changes of ATAC-seq signals between D10 and D21 LZ GC B cells for tdTomato+ and tdTomato- cells at IRF4-targeted PC-specific loci (n=4,477) (g), PC-specific loci (n=12,574) (h) and GC-specific loci (n=10,185) (i), respectively. P values by two-sided Mann-Whitney tests. j, Metaplot analysis comparing ATAC-seq signals between day-10 (D10) and day-21 (D21) tdTomato- LZ GC B cells at top 500 intact AICE peaks, partial AICE peaks and ISRE peaks, respectively. Data are shown as mean ± s.d. of biological replicates (n=3). P values by two-sided Kolmogorov-Smirnov tests. k, IGV tracks showing ATAC-seq signals at Prdm1 and Cd28 loci in tdTomato- D10 and D21 LZ GCs. l, IGV tracks showing ATAC-seq signals at PAX5 and BACH2 loci in tdTomato+ D10 and D21 LZ GCs. m-n, Representative histogram (m) and summary data (n) of IRF4 expression in day 14 and day 28 MBCs post NP-KLH immunization. Each symbol indicates one mouse (n=9 for day 14; n=11 for day28). P values by two-sided paired t tests.