CD8+FoxP3+ Treg display a distinct phenotype compared with CD4+FoxP3+ Treg. B6D2F1 recipients were lethally irradiated and transplanted with BM and T cells from B6.FoxP3-GFP donors 24 hours later. (A) At day 5 after transplantation, phenotyping was performed in the spleen and mLN. Representative plots from 2 experiments are shown from the spleen. (B) At day 5 after transplantation, B6.FoxP3-GFP mean fluorescence intensity was assessed. ***P < .001. Displayed results are from 6 mice, and similar results were confirmed at day 7 and day 12. (C) At day 7, spleens were removed and analyzed for expression of IL-10, IFN-γ, and IL-17 after phorbol myristate acetate and ionomycin stimulation. Concatenated plots from 2 replicate experiments are shown with quadrant statistics representing mean. Graph represents percentage of FoxP3 cells expressing the cytokine indicated. (D) Cytolytic activity of donor B6 FoxP3− and CD8 FoxP3+ T cells from transplanted B6D2F1 recipients in 51Cr release assays against host-type P815 mastocytoma. Results represent replicate wells from 2 experiments.
