(A) Representative CFSE dilution profiles of gated CFSE⁺CD4⁺CD25⁺CD127^– Tregs from Cd18^wt (left panel) and Cd18^hypo mice (right panel). (B) Representative CFSE dilution profile of gated CFSE⁺CD4⁺CD25⁺CD127^– Tregs from skin DLNs of Cd18^wt (left panel) and Cd18^hypo (middle panel) mice 7 days after adoptive transfer into affected Cd18^hypo recipients or of gated CFSE⁺CD4⁺CD25⁺CD127^– Tregs from Cd18^hypo mice 7 days after adoptive transfer into Cd18^wt recipients (right panel). Numbers on the top left of A and B indicate the percentage of CFSE-labeled proliferating cells. Numbers on the top right of A and B indicate the percentage of undivided CFSE-labeled cells. To investigate in vitro suppressive function of Tregs on Tresp cells, CD4⁺CD25⁺CD127^– Tregs were pooled from spleens of Cd18^wt or Cd18^hypo mice (4 animals for each group) and cultured with CFSE-labeled CD4⁺CD25^– Tresp cells derived from either affected Cd18^hypo mice (C) or Cd18^wt mice (D). A total of 1 × 10⁵ Tresp cells were incubated alone (gray bar, ratio 1:0) or with decreasing numbers of Tregs from Cd18^wt or affected Cd18^hypo mice (the ratio of Tregs/Tresp cells was at 1:1, 2:1, 4:1, 8:1, and 16:1). After 3 days cells were harvested and analyzed by flow cytometry. Representative data are shown, which had been reproduced in 3 independent experiments.