PD-1 Is a Selective Marker of Human Follicular T Cells
(A) Representative PD-1 expression levels determined by flow cytometry on electronically gated subsets of leukocytes in non-inflamed human tonsil.
(B) Median PD-1 expression (median fluorescence intensity) across major leukocyte subsets identified in 2 independent non-inflamed human tonsils.
(C) PD-1 expression across major leukocytes subsets identified in 3 healthy human PBMCs.