Figure 1.

Myeloid-derived suppressor cells express ENO1 on their surface in both PDA patients and tumor-bearing mice. (A) Freshly collected blood from PDA patients and healthy individuals was immediately stained to evaluate the presence of MDSC defined as CD11b⁺CD33^lowCD14⁻HLA-DR^low. In the graph, the percentage of CD11b⁺CD33^low or CD11b⁺CD33^high cells is plotted as whiskers from minimun to maximun value for PDA patients (black whiskers) and age-matched healthy individuals (white whiskers). Mean value for each group is also represented. *, ***p values < 0.05 and 0.0001 significantly discriminate PDA patients from healthy individuals. (B) ENO1 expression was evaluated on the aforementioned myeloid populations and the geometrical mean intensity of fluorescence was evaluated for each PDA patient (black bars) and age-matched healthy individual (white bars) after subtraction of the fluorescence intensity registered with the isotype IgG (Δ geo mean). Bars represent mean ± SEM. (C) Dot plots are representative of the gating strategy for the analysis of MDSC in human blood and of ENO1 expression on human MDSC. (C) MDSC defined as CD11b⁺Gr1⁺ cells were evaluated in the freshly collected blood from KC mice (black whiskers from minimun to maximun value; n = 5) and age-matched Cre mice (white whiskers from minimun to maximun value; n = 5) at different time point as indicated. *, **, ***p values < 0.05, 0.001 and 0.0001 significantly discriminate KC mice from Cre mice. (D) Representative flow cytometry histograms of ENO1 expression on CD11b⁺Gr1⁺ cells cultured or not (green peak) in the presence of LPS for 48 and 72 h and labeled with an anti-ENO1 mAb (blue and orange line peaks respectively) or an isotype ctrl (black peak). One of three independent flow cytometry evaluations is shown.