Fig. 9: Human basophils drive TFH cell and TFH2 cell differentiation through IL-4, IL-6 and PD-1 dependent mechanisms ex vivo.

Contour plots showing CD3/CD28-activated human CD4⁺ T cells cultured for three days without (a) or with (b) purified human basophils at a 5:1 ratio (left) and the condition-induced TFH differentiation of the CD4 + T cells (right). Basophils were defined as FcεRIα⁺ CRTH2⁺ CCR3⁺ cells and TFH cells were defined as CD4⁺ PD-1⁺ CXCR5⁺ ICOS⁺ cells. c Proportions (%) of TFH cells among CD3/CD28-activated CD4⁺ T cells cultured without (0:1) or with the indicated ratio of purified human basophils (n = 4 per group). d Proportions (%) of TFH cells among CD3/CD28-activated CD4⁺ T cells cultured without or with purified human basophils at a ratio of 1:5 in the absence (–) (blue) or presence of antibodies blocking IL-4 (αIL-4) (red), IL-6 (αIL-6) (orange) or PD-1 (αPD-1) (green) or the corresponding isotype controls (Iso) (blue) (n = 4/3/6/6/6/6/5/5/8/8/8/8). e Contour plots showing subsets of TFH cells as defined in Fig. 1 on cells as in (a, b). f Proportions (%) of TFH2 cells among TFH cells after culture as described in (d) (n = 5/5/8/8/8/8). TFH2 cells were defined as CD4⁺ PD-1⁺ CXCR5⁺ ICOS⁺ CCR6^– CXCR3^– cells. c, d, f Data are presented as individual values in bars representing the mean values ± s.e.m. c One representative experiment out of two with cells from 4 different donors is shown. d, f Results are from three independent experiments. c, d, f Statistical analyses were done by one-way ANOVA test followed by Tukey’s multiple comparisons tests between the indicated groups. P values are shown above each bracket. NS not significant. Source data are provided in the Source Data file.