Increased ratio of splenic donor Tregs to total donor Tcons in the presence of NK cells. (A) The percentage of donor Tregs (CD45.1⁺CD4⁺CD25⁺Foxp3⁺) reisolated from Tcon + NK groups was significantly higher in spleen and mLN (***P < .001 and *P < .05, respectively; pLN was NS) compared with Tcon. (B) Absolute donor Treg cell numbers were higher in the Tcon group compared with the Tcon + NK group (spleen, **P < .01; mLN, NS; pLN, *P < .05). Inset shows the same mLN and pLN data as large graph at higher magnification to visualize relative differences. (C) Ratios of donor Tregs/total donor Tcons (CD4⁺ and CD8⁺) were significantly higher in Tcon + NK animals than Tcon animals in the spleen (***P < .001). Results were mixed in the lymph node (mLN, NS; pLN, *P < .05). All data are from day 4 after T-cell transplantation, are averaged from 4 mice, and are representative of 3 independent experiments.