Figure 3.

CD28‐driven induction of IL‐17F⁺ CD4⁺ T cells is mediated in part by IL‐2. Bulk CD4⁺ T cells were cultured with anti‐CD3 mAb, IL‐23, and IL‐1β in the presence of increasing doses of anti‐CD28 mAb (0–2 μg/mL). (A) After 3 days, culture supernatant was collected and levels of IL‐2 protein were analysed by ELISA (cumulative data from three independent experiments from n = 4 donors in total). Data are shown as the mean ± SEM. Dashed red line indicates the lower ELISA detection limit, respectively. (B) Bulk CD4⁺ T cells were cultured with anti‐CD3 mAb, IL‐23, and IL‐1β in the absence or presence of anti‐CD28 mAb and anti‐IL‐2 mAb for 3 days. Graphs show cumulative data of the frequencies of total IL‐17A⁺ and IL‐17F⁺ CD4⁺ T cells (B) or IL‐17A⁺IL‐17F⁻, IL‐17A⁺IL‐17F⁺, and IL‐17F⁺IL‐17A⁻ CD4⁺ T cells (C) (data from five independent experiments using n = 8 donors in total). Statistical analysis was performed using Friedman test with comparison to all samples by Dunn's Multiple Comparisons test.