Fig. 4

Circulating monocytes from PDAC patients are able to restrain T cell proliferation in vitro. a Freshly isolated PMNs (CD66b⁺ cells, orange box) and monocytes (CD14⁺ cells, blue box) from PDAC patients analysed by flow cytometry and haematoxylin-eosin staining. b Functional assay reflecting the different ability of PMNs and monocytes to affect T cells proliferation when co-cultured in vitro with CD3/CD28-activated-PBMCs at different ratios. All values are normalized on the activated PBMCs in the absence of myeloid cells (grey bar) and reported as percentage of Cell Trace⁺CD3⁺ cells. Statistical analysis was performed by ANOVA test. c Functional assay performed (at 1:3 ratio of PBMCs:CD14⁺ cells) on monocytes of PDAC patients (n = 26) compared to HDs (n = 8), reported as percentage of CD3⁺ proliferating cells (right panel) and graphed as proliferation peaks of Cell Trace⁺CD3⁺cells after the co-culture (left panel). Among all PDAC patients, “Suppressive CD14⁺ cells” (blue) and “Non-suppressive CD14⁺ cells” (red) were grouped based on the quantitative analysis of the in vitro immunosuppressive function. Statistical analysis was performed by ANOVA test. d Different ability of suppressive and non-suppressive monocytes to limit CD3⁺ T cell proliferation at different cell ratios. Statistical analysis was performed by ANOVA test. e Pearson correlation between MDSC4 and MDSC1 among CD14⁺ cells of PDAC patients. f Pro-metastatic potential of suppressive CD14⁺ cells. Statistical analysis was performed by Pearson Chi-Square test