Mechanisms of IFN-mediated induction of IL-10 from T cells in Th17-polarizing conditions.

<p>(<b>A</b>). Proliferation of IL-10⁺ and IL-17⁺ CD4 T cells upon IFNβ treatment. Purified CD4 T cells were labeled with 5 µM of CFSE (carboxyfluorescein diacetate succinimidyl ester) and stimulated under the Th17 polarizing condition in the presence of IFNβ. After 3 days of culture, cells were stained for CD4, IL-10 and IL-17 and analyzed by FACS. Shown are representative CFSE profiles as well as intracellular IL-10 or IL-17 staining on gated CD4 cells. (<b>B</b>). Induction of IL-10 by IFNβ in fully differentiated Th17 cells. Naive CD4⁺ T cells were stimulated under the Th17-polarizing condition. After 3 days, T cells were re-cultured again for two more rounds under the same Th17 culture condition. In the third round of Th17 differentiation, T cells were treated with or without IFNβ. Expression of IL-17 and IL-10 was measured by intracellular cytokine staining and FACS analysis. Data are representative of three experiments with similar results.