Fig. 4

Th2 cell polarization requires strong IL-2 signaling, which is prevented by IL-6. A–I CTV-labeled WT.4get (CD45.1⁺) and Tbx21^−/−.4get (CD45.2⁺) CD4⁺ T cells from naïve mice were mixed 1:1 and stimulated in vitro with plate-bound anti-CD3 and soluble anti-CD28 for 48 hours. Anti-IL-2 Abs (JES6-1A12 and S4B6), anti-CD25 (PC-61.5.3), or rIL-6 was added at the indicated concentrations for an additional 72 hours. CTV profiles and frequencies of pSTAT5⁺, CD25⁺, and IL-4-GFP⁺ cells in WT (A, B, D–E, G, H) and Tbx21^−/− (A, C, D, F, G, I) CD4⁺ T cells. J, K CTV-labeled WT.4get CD4⁺ T cells from naïve mice were activated in vitro with plate-bound anti-CD3 and soluble anti-CD28 for 48 hours. Anti-IL-2 Abs (0.025 □g/ml), rIL-6 (0.2 ng/ml), or both were added for an additional 72 hours. CTV profiles (J) and frequencies of pSTAT5⁺, CD25⁺, and IL-4-GFP⁺ cells J, K. Data are representative of four independent experiments. All values were obtained in triplicate, and the data are shown as the mean±S.D