TCR avidity and CD28 co-stimulation signals regulate Th17 development.

<p>(A) Purified CD4⁺ T were stimulated with plate-bound anti-CD3 (5 µg/ml) and titrated doses of soluble anti-CD28 mAb under Th17 polarizing conditions. Cells were stained intracellularly for IL-17 and IFN-γ expression. The data shown is one representative experiment out of two. (B) CD4⁺ T cells were stimulated with titrated doses of plate-bound anti-CD3 in the presence or absence of soluble anti-CD28 mAb (2 µg/ml). Data represent the mean±SD of four independent experiments. (C) Cumulative data of viable CD4⁺ T cell recovery after stimulation with anti-CD3 (5 µg/ml) the presence or absence of anti-CD28 mAb (2 µg/ml). Data are the mean±SD of 3 (LNs) to 20 (spleen) independent experiments. (D) CD4⁺ T cells were stimulated with coated anti-CD3 (10 µg/ml) in the presence or absence of soluble anti-CD28 under Th17 conditions and analyzed at different time points for the percentage of apoptotic cells (Annexin V binding positivity). Mean values±SD obtained from at least three separate experiments are presented. P values were calculated using the two-tailed, paired Student's <i>t</i> test, *, P<0.05; **, P<0.01.