Figure 4.

Kinetics and activation of cTreg and cTfr cells after vaccination with YF‐17D. PBMCs isolated before (day 0) and at the indicated time points after YF‐17D vaccination were analysed by flow cytometry (see Supplementary figure 1 for the gating strategy). (a–c) Representative contour plots and quantification of frequencies of (a) circulating CXCR5⁻ Treg and CXCR5⁺ Tfr cells, (b) activated CD38⁺ cTreg and (c) activated CD38⁺ CXCR5⁺ Tfr cells are shown. Gate frequencies indicate the frequency in regard to the parent gate. Gate frequencies in brackets indicate the frequency of the population in regard to the reference population as indicated above. Pooled data from four independent experiments with 5 to 10 study participants each are presented as Tukey boxplots showing the median with the 25th and 75th percentile (n = 33) and whiskers and outliers calculated as highest and lowest observation below/above 1.5 times interquartile range. Data points below/above 1.5 times interquartile range are displayed individually. Statistical analysis was performed using RM one‐way ANOVA and Dunnett's multiple comparison analysis to compare indicated time points to day 0. ***P < 0.0002, ****P < 0.0001.