Online supplemental material

Fig. S1 shows the frequency of CD25⁺ cells in human lymph node tissue. Fig. S2 shows IL-21 production by the different T_F cell subsets. Fig. S3 compares T reg cell– and T_FH cell–associated protein expression among CD25⁺ T_F cells and the more classical FOXP3⁺ T_FR cells. Fig. S4 shows that CD25⁺ T_F-mediated repression of T_FH cells is IL-10 independent, as well as repression of εGLTs in IgG⁺ and IgM⁺ memory B cells. Fig. S5 shows Pearson correlation analyses between the frequency of CD25⁺ T_F cells in tonsil versus IgG4 serum titers.