Figure 8. Suppressive function of Cd28-ΔTregs.

(A) In vitro suppression assay. Sorted WT naive cells were stimulated by soluble CD3 and T cell–depleted splenocytes with the addition of different ratios of WT Tregs or Cd28-ΔTregs. Tregs were sorted from 4-week-old mice. Teff, effector T cells. (B) In vivo colitis induction. Weight loss of Rag1^–/– mice adoptively transferred with sorted CD4⁺CD45RB^hi effector T cells with or without WT Tregs or Cd28-ΔTregs. A total of 6 mice were analyzed for each group. Data represent mean ± SEM. (C) H&E staining of the colons of mice in B. Original magnification, ×100. (D and E) Representative analysis of donor CD45.1⁺CD4⁺ effector cells and regulatory cells in the colons of mice in B. (F) Sorted WT Tregs or Cd28-ΔTregs were labeled with CellTrace Violet and adoptively transferred to Rag1^–/– hosts. Lymph node cells were analyzed 7 days after transfer. Data are representative of 3 experiments.