Fig. 7

Spike-specific CXCR3⁺ T_FH cells were more able than spike-specific CXCR3⁻ T_FH cells to support ASCs differentiation in vitro. a Diagram of T_FH cells or non-T_FH cells coculturing with autologous memory B cells. b Representative flow plots of spike-specific ASCs after coculturing T_FH cells or non-T_FH cells with autologous memory B cells from healthy controls, convalescents, and vaccinees in the presence of SEB (100 ng/mL) for 6 days. c–e Comparison of total ASCs, spike-specific ASCs, and spike-specific IgG in the supernatant between T_FH and non-T_FH cells after coculture with autologous memory B cells from healthy controls (n = 6), convalescents (n = 5), and vaccinees (n = 9). f Comparison of the total ASCs, spike-specific ASCs, and spike-specific IgG from before (n = 7) and after (n = 7) the third booster dose. g Diagram of CXCR3⁺ T_FH cells or CXCR3⁻ T_FH cells coculturing with autologous memory B cells. h Representative flow plots of spike-specific ASCs after coculturing of CXCR3⁺ or CXCR3⁻ T_FH cells with autologous memory B cells from healthy controls, convalescents, and vaccinees in the presence of SEB (100 ng/mL) for 6 days. i–k Comparison of frequencies of total ASCs, spike-specific ASCs, and spike-specific IgG in the supernatant between CXCR3⁺ T_FH cells and CXCR3⁻ T_FH cells after coculturing with autologous memory B cells from healthy controls (n = 8), convalescents (n = 9), and vaccinees (n = 7) in the presence of SEB (100 ng/mL) for 6 days. For (c–f) and (i–k), paired t test was used to analyze the differences between the two groups. *P < 0.05; **P < 0.01. P < 0.05 was considered to be a two-tailed significant difference; ns, not significant