Distribution of mononuclear cells in different healthy human tissues. Mononuclear cells were isolated from healthy human PB, BM, liLNs, inLNs, and SPL samples and analyzed by flow cytometry. (A) Distribution of CD3^posCD4^pos helper T cells (T4), CD3^posCD8^pos T cells (T8), CD19^pos B cells (B), CD56^posCD3^neg NK cells (NK), and CD14^pos monocytes (Mo). Data are depicted as percentages of cell type within the CD45^pos mononuclear gate. Each line represents 1 sample (N = 4-8 for each tissue). (B) Representative examples of CD25/CD127 staining on CD4^pos T cells and FoxP3 expression on CD25^posCD127^neg (gray filled histograms) and CD25^negCD127^pos cells (black line histograms). (C) Summary of percentages of CD25^posCD127^neg Tregs within CD4^pos T cells (N = 10-14 for each tissue). Data were compared using 1-way ANOVA and no significant differences were found.