FIGURE 3. Expansion of Foxp3⁺ Treg correlates inversely with TCR signaling via Akt/mTOR/S6.

A, upper panels, CD4⁺ BDC2.5 T cells were stained for expression of phosphorylated S6 ribosomal protein (pS6) after 18hrs stimulation with G4DC plus indicated dose of AV10 peptide. A, lower panels, pS6 and Foxp3 in CD4⁺ DO11.10 T cells at 18hrs stimulation with G4DC plus OVA³²³. B, pS6 MFI (left) and % CD4⁺ Foxp3⁺ T cells (right) expression, measured by flow cytometry, in BDC2.5 T cells after 18hr, 3d and 7d stimulation with AV10-loaded G4DC. A and B are representative of ≥3 similar experiments. C, pS6 at 18hrs and Foxp3 at 7 days in BDC2.5 T cells stimulated with G4DC and varying doses of AV10. Graph shows the mean and standard deviation from three independent experiments. D, Inverse relationship of 18hr P-S6 and 7d Foxp3. C&D, Data points derive from three separate experiments. 18 hr pS6 levels were normalized within each experiment to unstimulated control T cells.