Fig. 1: CD39 expression is higher on IL-10⁺ B cells than IL-10⁻ B cells from tonsils and peripheral blood mononuclear cells.

a A representative FACS plot showing IL-10⁺ and IL-10⁻ B cells in the blood of healthy subjects (upper panel). Cells were gated based on isotype antibody staining. Summarized data for the frequency of IL-10⁺ B cells (lower panel). Individual dots represent data generated with cells from different donors (n = 5). b Summary of FACS array data. Heatmap illustrating the expression levels of various cell surface markers on IL-10⁺ and IL-10⁻ B cells. Tonsillar mononuclear cells (MNCs) and peripheral blood mononuclear cells (PBMCs) were stimulated with CpG-B for 48 h. PMA/ionomycin, brefeldin A, and monensin cocktails were added for the last 5 h of the culture. Cells were stained with antibodies specific for cell surface molecules. Cells were then stained for intracellular IL-10 expression. Mean florescence intensity (MFI) was acquired upon subtracting isotype control. Cell surface markers with ΔMFI ≥ 500 between IL-10⁺ and IL-10⁻ B cells are presented. The colored scale shows the expression level (ΔMFI) of each cell surface markers on IL-10⁺ and IL-10⁻ B cells. Purple (ΔMFI > 25% by rank), yellow (ΔMFI = 25–65% by rank), and red (ΔMFI < 65% by rank) colors were used to indicate low to high level of expression. c MFI values of surface IgD, IgM, CD24, CD25, CD27, CD38, CD71, CD73, CD147, and TIM-1 on CD39^high and CD39^low/− B cells. Cells were stained without activation. Data generated with cells from different healthy subjects (n = 5) were combined. Error bars are mean ± SD in a. P values were determined with a two-tailed unpaired t test in a and a paired t test in c.