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-CD45RbHi/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-CD45RbLoCD62L-CD44+ (RbLoTem) or CD4+FoxP3- CD45RbHiCD62L+CD44- (RbHiTn) cells. * = p0.05. 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.