Fig 1. IL-10 production by Tregs is synergistically enhanced by CD4⁺FoxP3^-CD45Rb^LoCD44⁺CD62L^- T cells.

Tregs and various CD4⁺ T cell subsets were cultured in vitro with plate-bound anti-CD3ε antibody for 3 days, unless otherwise specified, to measure their cytokine responses by ELISA. (A) Comparison of mono- and co-cultures of magnetic bead purified (M) CD4⁺ Tconv and CD4⁺CD25⁺ Tr cells vs. flow sorted (Fl) CD4⁺CD25⁺ Tr cells. (B) Time course of cytokine production from co-cultures of flow-sorted Tconv and CD25⁺ Tregs. (C) Co-cultures of flow-sorted 50k Tconv and varied Tregs at indicated ratios. (D) 1:1 Cultures of flow sorted CD4⁺FoxP3⁺ Tregs and CD4⁺FoxP3^-CD45Rb^Hi/Lo cells, showing IL-10, IFNγ, and IL-2 production by ELISA. (E) 1:1 cultures of CD4⁺CD25⁺FoxP3⁺ Tregs and CD4⁺CD25^-FoxP3^-CD62L⁺CD44⁺ (Tcm), CD4⁺CD25^-FoxP3^-CD62L^-CD44⁺ (Tem), and CD4⁺CD25^-FoxP3^-CD62L⁺CD44^- (Tn) cells. (F) 1:1 cultures of CD4⁺CD25^-FoxP3⁺ Tregs and Tcm, Tem, or Tn cells. (G) 1:1 cultures of CD4⁺FoxP3⁺ Tregs and CD4⁺FoxP3^-CD45Rb^LoCD62L^-CD44⁺ (Rb^LoTem) or CD4⁺FoxP3^- CD45Rb^HiCD62L⁺CD44^- (Rb^HiTn) cells. * = p<0.05; # = p>0.05. P value calculated from Student’s T-Test. Error bars show mean with SEM. For A-B and D-F, n = 3 experiments. For C, n = 6 experiments. For G, n = 4 experiments.