Figure 6.

IL-6 and IL-27 inhibit Treg cell suppressive function ex vivo. Treg cells (CD4⁺CD25^HighCD127^Low) cells were FACS-sorted and co-cultured with CFSE-labeled, FACS-sorted CD4⁺CD25⁻ Teff cells in the presence exogenous IL-6 or IL-27. Cells were stimulated with human αCD3/αCD28 coated beads (Treg Suppression Inspector; MACS Miltenyl Biotec) at a 1:2 bead: cell ratio for 96 h. Treg and Teff were plated at a ratio of 0:1 or 1:8, (A) The effects of rhIL-6 on the suppressive function of Treg cells. (B) The effects of rhIL-27 on the suppressive function of Treg cells. (C) The impact of IL-6 and IL-27 on the proliferative response of Teff cells activated in the absence of Treg cells. (D) Gp130^High and gp130^Low Treg cells (CD4⁺CD25⁺CD127^Low) were FACS-sorted and stimulated with human αCD3/αCD28 coated beads for 48 h in the presence of CD4⁺CD25⁻ Teff cells at a 1:4 Treg:Teff ratio. Where indicated, rIL-6 (10 ng/mL) or rIL-27 (10 ng/mL) was added. Helios expression was assessed by flow cytometry. Data are representative of at least three independent experiments performed on cells isolated from different healthy individuals. Statistical analysis was done with the one-way ANOVA followed by the Dunnett post-test. **p < 0.01, ***p < 0.001, ****p < 0.0001.