Figure 4.

MDSCs have suppressive effect for T cells and induce a polarization of helper T cells. (A) Healthy adult PBMCs were labeled with CFSE and stimulated with Dynabead Human T-Activator CD3 and CD28 in the presence of MDSCs at a 1:1, 1:0.5, and 1:0.25 (PBMCs: MDSCs) ratio. After 6 days, cells were then harvested, stained with anti-human CD3 (PE-Cy7), anti-human CD4 (APC) and anti-human CD8 (efluor450) antibodies. The cells were analyzed by FACSCanto II device. (B) CD4⁺ T cells were isolated from healthy adult PBMCs and 1 × 10⁶ CD4⁺ T cells were stimulated with 0.5 μg/mL Dynabead Human T-Activator CD3 and CD28 in the presence or absence of 2 × 10⁶ MDSCs at a 1:2 (CD4⁺ T cells: MDSCs) ratio in 12 well plates for 3 days. After 3 days, the cells were stained with fluorochrome-conjugated anti-human CD3 (PE-Cy7), anti-human CD4 (FITC), anti-human CD25 (APC), anti-human IL-17 (PerCP-Cy5.5) and anti-human FoxP3 (PE) antibodies. (C) Human IL-17 and IFN-γ was measured in the culture supernatants of (B). Data are mean ± S.E.M. of three independent experiments, each performed in triplicate. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.