Fig. 3

Activation of human B cells negatively regulates TGF-β1 production. a Frequencies of TGF-β1-producing B cells from human blood. Cells were cultured with medium or with combined CpG-B + anti-Ig for 24 h. PMA/ionomycin and monensin were added 5 h before the end of the culture. Cells were stained for surface CD19 and CD27 and intracellular TGF-β1 (top panels) or matched isotype control (bottom panels). The representative dot plots show frequencies of TGF-β1-producing cells among CD19⁺CD27⁻ or CD19⁺CD27⁺ B cells. b The bar graph indicates mean (± SEM) percentages of B cells that labeled positively for TGF-β1 (n = 6). Percentages presented are corrected for isotype control staining. c Line plot of frequencies of TGF-β1-producing cells among CD19⁺CD27⁻ or CD19⁺CD27⁺ B cells. Paired data are shown interconnected. d The bar graph indicates quantification (mean ± SEM) of TGF-β1 staining in both CD19⁺CD27⁻ and CD19⁺CD27⁺ B cells (n = 6). Geometric MFI were normalized to the isotype control. e The line plot shows normalized TGF-β1 MFI by cells among CD19⁺CD27⁻ and CD19⁺CD27⁺ B cells. Paired data are shown interconnected. Significant differences using Student’s t test between sample means are indicated