Higher Tregs frequency and reduced donor T-cell proliferation in αDR3 group during the effector phase. 5 × 10⁵ donor T cells from αDR3 or isotype mAb–treated CD45.1⁺ C57BL/6 mice and 5 × 10⁶ TCD-BM cells from C57BL/6 mice were transplanted into lethally irradiated Balb/c mice. (A) The frequencies of FoxP3⁺ cells in donor CD4⁺ T cells in peripheral blood were analyzed on days 20, 40, and 60 after BMT. FoxP3⁺(%) of CD45.1⁺ CD4⁺ T cells of either group were compared by multiple Student t tests with Holm-Sidak correction. These are the combined results of 2 experiments (n=11 [day 20], 9 [day 40], 8 [day 60] for isotype and n = 9 [day 20], 9 [day 40], 8 [day 60] for αDR3 group; ***P < .001, ****P < .0001). (B) LNs and spleen were harvested on day 28 after in vivo BrdU labeling. BrdU uptakes of CD45.1⁺ FoxP3^– CD4⁺ (left) and CD45.1⁺ CD8⁺ T cells (right) are shown (*P < .05, **P < .01, ***P < .001). These are the combined results of 2 experiments (n= 6 [LN], 13 [spleen] for isotype and n = 5 [LN], 13 [spleen] for αDR3 group). (C-D) Serum levels of TNFα (C) and IFNγ (D) were measured in recipient mice on day 28 by multiplex assay. The combined results of 2 independent experiments are shown (n = 13 in each group; **P < .01; NS, not significant).