α-GalCer-lipo administration enhances the in vivo expansion of transferred Tregs. Flow-sorted Foxp3^GFP+Luc+ cells were injected into recipient mice at 1:10 Treg/Tcon ratio at the time of BMT. Recipient mice were treated with Ctrl-lipo or α-GalCer-lipo. (A) Survival curve. (B) Images of photons from Foxp3^GFP+Luc+ cells in 1 representative experiment. White X indicates mice already dead at the analysis. (C) Mean ± standard error of the mean for total flux (photons per second [p/s]) from transferred Foxp3^Luc+ cells in indicated groups. Data pooled from 3 independent experiments. **P < .01 calculated by log-rank test between indicated 2 groups (A) or by 2-way analysis of variance between Ctrl-lipo and α-GalCer-lipo at indicated time point (C), ***P < .001 by 2-way analysis of variance between Ctrl-lipo and α-GalCer-lipo at indicated time point. BMC, BM cell; TBI, total-body irradiation.