Figure 1.

Generated M-MDSCs have an immature myeloid phenotype that is stable upon stimulation.A, schematic overview of myeloid generation protocols. Phenotype of harvested cells was determined by flow cytometry, shown are (B) MFI and percentage positive cells of lineage markers (n = 7–13), (C) expression of phenotype markers with and without maturation cocktail treatment consisting of IL-1β, TNFα, IL-6, and PGE-2 (n = 3), (D) MFI and percentage positive cells of costimulatory receptors (n = 3–9) and (E) MFI and percentage positive cells of co-inhibitory markers PD-L1 and MerTK (n = 3–7). F, M-MDSCs were stimulated with IFNγ (10 ng/ml), lipopolysacharide (100 ng/ml), Zymosan (1 × 10⁶ beads/ml), or PGE-2 (3,5 μg/ml), and after 48 h, phenotypic maturity was assessed. HLA-DR MFI of treated cells was divided by MFI of untreated cells (n = 3–4). One way ANOVA of unmatched values in all graphs except for the two way ANOVA of unmatched values in panel C. All obtained p-values were adjusted by bonferroni correction. Mean + SD are shown in all graphs ∗∗∗∗p < 0.0001, ∗∗∗p < 0.001, ∗∗p < 0.01, ∗p < 0.05, ns = non significant. MDSC, myeloid-derived suppressor cell; MFI, mean fluorescence intensity; M-MDSC, monocyte-derived-MDSC.