Expression data from developing regulatory T cells

CD25+ regulatory T cells develop in the thymus (nTregs), but may also be generated in the periphery upon stimulation of naive CD4 T cells under appropriate conditions (iTregs). The mechanisms that regulate the generation of peripheral iTregs are largely unknown. We used microarrays to gain insights into the molecular program of extrathymic Treg development Human iTregs were generated in vitro from CD4CD25- naive T cells in the presence of autologous feeder cells and interleukin (IL)-4. Total RNA was isolated at start and from purified CD25+ and CD25- T cells at days 3, 5, 7, and 10 of culture and used for DNA microarrays. CD25+ T cells generated in the absence of IL-4 constituted activated effector T cells (Teffs) lacking regulatory capacity and were therefore used to control for Treg-specific gene expression.