Figure 4.

Presence of Bregs at the tumour site. Multiparametric flow cytometry analysis of tumour cell suspension of patient no. 11. Bregs were defined as CD19⁺CD5⁺CD38⁺ cells producing IL10 and GZMB. (a) Dot plots showing the gating strategy CD19⁺ B cells were defined inside live CD45⁺ cells, and the CD5⁺CD38⁺ double-positive population was identified among the live CD19⁺ B cells. The percentage of cells producing IL10 and GZMB was evaluated by intracellular staining in the CD5⁺CD38⁺ subpopulation among unstimulated cells (b) and cells stimulated overnight with LPS and PMA/ionomycin (c). The basal production of IL10 and GZMB is boosted by stimulation. The percentage of positive cells is shown in each plot.