FIG. 3.

Fewer cytokine-producing cells in the draining lymph nodes of TGF-β–expressing grafts. Spleen, draining RLNs (dRLNs), and control RLNs (cRLNs) were harvested 5 days after transplantation and restimulated for 5 h with phorbol myristic acid and ionomycin. IL-10 (A) and IFN-γ (B) production was assessed by intracellular staining for flow cytometry and was lower in the CD4⁺ and CD8⁺ T-cell populations in mice receiving TGF-β–expressing grafts than in those receiving WT grafts. Differences between groups (technical triplicates) were assessed using the Student t test, and the results are representative of four independent experiments, each comparing one recipient of WT islets and one recipient of TGF-β–expressing islets. The ratio of IL-10 to IFN-γ–positive cells in the spleen and dRLNs was assessed in CD8⁺ T cells (left) and CD4⁺ T cells (right) (C). NS, not significant. *P ≤ 0.05, ***P ≤ 0.001.