Figure 4.

Distinct CD4⁺ T cell subsets contribute to the generation of Tfh with heterogeneous functional profiles

(A) Mean fluorescence intensity of the CXCR5 marker expressed by CXCR5⁺ PD-1⁺ cells derived from (1) naive, (2) MemPD-1^neg, (3) MemPD-1^neg and Tfh.

(B) Frequency of IL-21- and/or IFNγ-positive cells among CXCR5⁺ PD-1⁺ cells at day 3.

(C–E) Representative flow plots showing CXCR3, ICOS, and CD40L expression by CXCR5⁺ PD-1⁺ cells (left panel) and frequency of CXCR3-, ICOS-, and CD40L-positive cells among CXCR5⁺ PD-1⁺ cells at day 3 (right panel).

(F) Ex vivo cells or their respective Tfh^D3 counterparts obtained after 3 days of splenocyte culture were co-cultured with autologous B cells for 7 days.

(G) Box plots represent the frequency of CD27⁺ CD38⁺ cells among CD19⁺ cells, the concentration of total immunoglobulins and the absolute number of live B cells after co-culture.

(H) Quantification of IgG1, IgG4, and IgA in the co-culture supernatants. Each symbol (A–H) represents an individual donor. (A–H) A Wilcoxon matched pairs test was performed, ∗, p < 0.05; ∗∗, p < 0.005; ∗∗∗, p < 0.001.