Host iNKT cells are required for GVHD protection after α-GalCer-lipo treatment. (A) T cell–depleted BM cells (BMCs) and Tcons isolated from C57BL/6 Jα18^−/− mice (H2^b) were transferred into WT BALB/c mice (H2^d) together with purified Foxp3^GFP+ Tregs that were obtained from C57BL/6 Foxp3^GFP+ mice (H2^b). (B) T cell–depleted BMCs and Tcons were obtained from WT C57BL/6 donor mice (H2^b) and transferred into BALB/c Jα18^−/− mice (H2^d) together with C57BL/6 Foxp3^GFP+ Tregs (H2^b). Ctrl-lipo (blue) or α-GalCer-lipo (red) was injected right after cell transfer. Pooled data from 2 independent experiments. **P < .01 by log-rank test between 2 indicated groups.