The α_E⁺ Tregs from WT and FucTVII^–/– mice show similar Foxp3 expression and in vitro suppressive capacity. (A) Intracellular expression of Foxp3 in α_E⁺ Tregs from DO11.10 (WT) and DO11.10 × FucTVII^–/– mice is shown. Representative histogram plots from 3 independently analyzed mice were selected. (B) In vitro suppressive capacity of α_E⁺ Treg subsets from DO11.10 and DO11.10 × FucTVII^–/– mice on naive T-cell proliferation was determined after 72 hours of coculture with CFSE-labeled responder cells at a 1:1 ratio. Culture of CFSE-labeled responder cells alone (medium) served as control. Representative histogram plots of CFSE profiles from CFSE⁺CD4⁺ T cells are shown. Quantification of suppressive capacity is based on the CFSE geometric mean of total CFSE⁺CD4⁺ T cells (n = 3; mean ± SD; 1 representative of 2 independent experiments).