Fig. 1

Gating strategy of two panels for identification of B cell subsets. A lymphocyte gate was selected in the forward scatter area (FSC-A)/side scatter area (SSC-A) scatter plots, then a singlet gate was strictly created in the FSC-A/forward scattering height (FSC-H) scatter plots. A total of 2 × 10⁶ events were collected within the singlet gate with low flow rate for analysis. A A six-colour panel included CD3, CD19, CD20, CD27, CD43 and CD38 antibodies to distinguish CD3⁻CD19⁺D20⁺CD27⁺CD38^lo/intCD43⁺ B1 cells. B The other six-colour panel was designed for CD19, CD27, CD38, IgD, CD5 and CD24 antibodies to identify CD19⁺CD5⁺ B cells, CD19⁺CD24^hiCD38^hi regulatory B cells (Breg), CD19⁺IgD⁻CD27⁻ double negative B cells (DN), CD19⁺IgD⁺CD27⁺ unswitched memory B cells (USwM), CD19⁺IgD⁻CD27⁺CD38⁺ switched memory B cells (SwM), CD19⁺IgD⁻CD38^hiCD27^hi plasmablast (PB), CD19⁺IgD⁺CD27⁻CD38⁻CD24⁺ naïve B cells, CD19⁺IgD⁺CD27⁻CD38⁺CD24^lo mature B cells and CD19⁺IgD⁺CD27⁻CD38^hiCD24^hi Transitional B cells (Tr)