Fig. 1

The gating strategy of B cells and CD4⁺T cells populations. CD19⁺cells were gated. Plasma cells were determined as CD19⁺ CD20⁻ CD38⁺ CD27⁺ cells. Class switch B cells (CSB: CD19⁺ IgD⁻ CD27⁺), Non class switch B cell (NCSB: CD19⁺ IgD⁺ CD27⁺), Double negative B cell (DNB: CD19⁺ IgD⁻ CD27⁻), Naive B cell (NB: CD19⁺ IgD⁺ CD27⁻) subsets were gated based on gated B cells. Two subsets of regulatory B cells (Breg) cells were determined as CD19⁺ CD24⁺ CD38^high and CD19⁺ CD24⁺ CD27⁺ cells. Then CD3⁺ CD4⁺ cells were gated. Follicular helper T cells (Tfh cells) were determined as CD3⁺CD4⁺ CXCR5⁺PD-1^high cells. Th1, Th2 and Th17 cells were identified as CXCR6⁻CXCR3⁺ (Th1), CXCR6⁻CXCR3⁻ (Th2) and CXCR6⁺CXCR3⁻ (Th17) within CD3⁺CD4⁺ group. CD80, CD86 and CD40 were gated based on gated CD19⁺cells. CD28 and CTLA4 were gated based on gated CD3⁺ CD4⁺ cells. ICOS and IL-21 were gated based on gated Tfh cells