Decreasing activation signal strength results in increased functionality of Th17 cells
(A) CD4+ T cells from normal human donors were isolated and expanded with either CD3/CD28 or CD3/ICOS artificial APC beads and Th17 polarizing cytokines. (B) Percentages of IFNγ and IL-17A cytokine-producing Th17 cells expanded for 9 days after activation with either CD3/CD28 (top) or CD3/ICOS (bottom) beads at indicated bead:T cell ratios, as assessed by flow cytometry. (C) Average percentage of IFNγ+IL-17A+Th17 cells (±SEM) at day 10 post-activation, n = 3. (D) Average percentages (±SEM) of IL-17A, IL-22, IFNγ, and IL-2 cytokine-producing Th17 cells activated with a range of αCD3/αICOS bead:T cell ratios as determined by flow cytometry. Shaded area indicates the range of observed optimal cytokine production containing the three highest averages for each cytokine (n = 6 healthy donors). Statistical analysis was performed using two-way ANOVA with Tukey’s multiple comparisons test (∗p < 0.05, ∗∗p < 0.01, ∗∗∗∗p < 0.001).