Fig. 1

Phenotypic and transcriptional distinction between B cell subsets in Peyer’s patches. a Flow cytometry of PPs live CD3^-CD19⁺B220⁺ B lymphocytes (gated as shown in Fig. S1A) and separated into the small and large B cell subsets by forward scatter area and expressed as mean FSC-A (size), and the number of small-B and large-B cells per mg tissue (n = 6 mice left panel; n = 24 mice right panel). b Imaging flow cytometry of the areas (μm²) of small-B and large-B cell from three independent experiments. c, d Immunohistochemistry of PPs stained with anti-B220 (magenta), anti-CD138 (yellow) and Hoechst (blue) in c or anti-B220 (white), anti-GL7 (green), anti-Ki67 (cyan), anti-IgA (yellow), and anti-IgD (blue) in d. Scale Bars equal 100 μm or 10 μm in closed-up reviews. e Enrichment of gene ontology categories (Biological Process, BP) for genes differentially expressed in large B (upper panel) versus small B cells (lower panel) determined by microarray of lin^-CD19⁺B220⁺ cells sorted on FSC-A (n = 4 samples per group), the number of genes in each functional category is shown. Data were adjusted by false discovery rate control (FDR). f, g Displays of heat maps of genes expression by q-RT-PCR in sorted small and large B cells. The expression was normalized to the mean value of large B and each column represents one sample. h, i Heat maps and histograms depicting expression of surface markers on small and large B cells (n = 6 mice per group). The frequency of indicated markers (normalized to the mean value of large B cells). i MFI of B cells positive for GL7 and S1PR1, and percentage in each subset. Data are presented as mean ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001 using two-tailed Student’s t test