Low TCR and CD28 stimulation supports T_H17 development.

<p>(A) IL-17 and IFN-γ production of CD4^<b>+</b> T cells stimulated with different amounts of αCD3. Percentage of positive cells is indicated in the dot plot. (B) Depicted is the IL-17 and IFN-γ production of CD4^<b>+</b> T cells stimulated with 0.01 or 1 μg/ml αCD3 (n = 6, <i>M</i> ± SEM, Wilcoxon rank sum test, between IL-17^<b>+</b>CD4^<b>+</b> cells: not significant, between IFN-γ^<b>+</b>CD4^<b>+</b> cells: <i>p</i> = 0.06). (C) Ratio of αCD44-treated and untreated IL-17^<b>+</b>CD4^<b>+</b> or IFN-γ^<b>+</b>CD4^<b>+</b> T cells stimulated with 0.01 or 1 μg/ml αCD3 (n = 3, <i>M</i> ± SEM, paired t test, between IL-17^<b>+</b>CD4^<b>+</b> cells: *<i>p</i> ≤ 0.05, between IFN-γ^<b>+</b>CD4^<b>+</b> cells: not significant). (D and E) Magnetically sorted CD4^<b>+</b> T cells were stimulated four days with allogeneic BMDCs. Co-cultures were left untreated or 1 μg/ml CTLA-4-Ig was added. Percentage of IL-17^<b>+</b>CD4^<b>+</b> T cells of differently treated co-cultures is shown as a representative dot plot (D) and in a bar chart (E: n = 7, <i>M</i> ± SEM; Wilcoxon rank sum test, *<i>p</i> ≤ 0.05). (F) Magnetically sorted CD4^<b>+</b> T cells were stimulated four days with allogeneic BMDCs. Co-cultures were left untreated or were treated with 1 μg/ml CTLA-4-Ig or 10 μg/ml αCD44 or both. IL-17 and IFN-γ production of CD4^<b>+</b> T cells of the differently treated co-cultures is shown as a representative dot plot out of two independent experiments.