Figure 1. Vaccination increases the frequency of activated pTfh cells.
A) Gating strategy to identify pTfh cells, defined by co-expression of PD-1 and CXCR5 on CD4+ T cells. We measured ICOS, CD38, and Ki-67 on pTfh cells. A representative individual pre and post-vaccination is shown. B) The frequency of CD4+ T cells with the pTfh phenotype did not significantly change pre and post-vaccination for the pooled cohort. C–E) The frequency of ICOS+ pTfh cells (C) CD38+ pTfh cells (D) and Ki67+ pTfh cells increase increased post-vaccination. (Wilcoxon signed rank test).