Inhibition of Th17 differentiation by anti-CD28 mAb is not correlated with a expansion of Foxp3⁺ T cells.

<p>Purified CD4⁺ T cells were stimulated with plate-bound anti-CD3 in the presence or the absence of soluble anti-CD28 mAb under Th17 polarizing conditions. (A) The proportion of Foxp3⁺CD4⁺ T cells. Data from 8 independent experiments are shown. (B and C) CD4⁺, CD4⁺CD25⁻ T cells and CD4⁺CD25⁻ T plus CD4⁺CD25⁺ T cells (at 1/1, 4/1 CD25⁻/CD25⁺ T cell ratios) were stimulated as described. Numbers indicate the percentage of IL-17 and IFN-γ-expressing CD4⁺ T cells (B) and IL-17 and Foxp3-expressing cells (C). One of 2 representative experiments is shown. P values were calculated using the two-tailed, paired Student's <i>t</i> test, **, P<0.01.