mESC-derived TEP treatment results in enhanced numbers of total, naive, and regulatory T cells in the spleen after allo-BMT. (A-E) Lethally irradiated C57BL/6 mice were injected intrathymically with mESC-derived EpCAM1⁺, EpCAM1⁻ cells, or PBS, and intravenously with TCD-BM from BALB/c mice as in Figure 1B. Thirty days after BMT, the numbers of splenic (A-B) total, (C-D) donor-origin naive CD4⁺ and CD8⁺ T cells, and (E) donor-origin regulatory T cells (CD4⁺ CD25⁺ FoxP3⁺) were evaluated by flow cytometry. (F) Groups of mice were injected intrathymically with biotin at 30 days after BMT. After 24 hours of in vivo labeling, the export of thymus-derived T cells into the spleen was evaluated. Means ± SDs are presented (n = 5-6). ***P < .001. The data are representative of 3 independent experiments.