Figure 1.

Polarization and cytokine production of CD4⁺ T cells under the influence of cord blood myeloid‐derived suppressor cells (CB‐MDSC). CB‐MDSC were enriched from cord blood mononuclear cells (CBMC) and added to peripheral blood mononuclear cells (PBMC) isolated from a healthy adult control. After 5 days of culture surface staining (a–c), stimulation for 5 hr with GolgiPlug and intracellular staining for interferon‐γ (IFN‐γ) and interleukin‐4 (IL‐4) (d–f) or intracellular staining for FoxP3 (g, h) was performed and cells were analysed by flow cytometry. (a) Gating strategies for CD4⁺ CD183⁺ CD194⁻ CD196⁻ Th1 cells and CD4⁺ CD183⁻ CD194⁺ CD196⁻ Th2 cells. (b, c) Scatter plots with bars show the percentage of CD183⁺ CD194⁻ CD196⁻ Th1 cells and CD183⁻ CD194⁺ CD196⁻ Th2 cells of CD4⁺ cells without addition of CB‐MDSCs (white bars) and with addition of CB‐MDSCs (grey bars). Bars represent pooled data from 10 independent experiments and each point represents an individual sample. **P < 0·01, ***P = 0·0003; paired t‐test. (d) Density plots for FL‐1 versus IFN‐γ (upper plots) and FL‐1 versus IL‐4 (lower plots) without addition of CB‐MDSCs (w/o MDSC) and with addition of CB‐MDSCs. Cells were pre‐gated for CD4. (e, f) Scatter plots with bars show the percentage of IFN‐γ⁺ cells and IL‐4⁺ cells of CD4⁺ cells without addition of CB‐MDSCs (white bars) and with addition of CB‐MDSCs (grey bars). Bars represent pooled data from 14 independent experiments each point represents an individual sample. ***P = 0·0002, ****P < 0·0001; Wilcoxon matched‐pairs signed rank test and paired t‐test. (g) Density plots for FoxP3 versus CD25 shows gating strategies for CD4⁻ CD25^high FoxP3⁺ regulatory T (Treg) cells without addition of CB‐MDSC (left plot) and with addition of CB‐MDSC (right plot). Cells were pre‐gated for CD4. (h) Scatter plot with bars show percentage of CD4⁻ CD25^high FoxP3⁺ Treg cells without addition of CB‐MDSC (white bar) and with addition of CB‐MDSC (grey bar). n = 10, ****P < 0·0001: paired t‐test.