FIG 2.
The highly immunosuppressive tumor microenvironment of pancreatic ductal adenocarcinoma. Pancreatic tumor cells, myeloid cells (Mo-MDSCs, TAMs, and Gr-MDSCs), and fibroblasts within the tumor microenvironment interact through various ligands, cytokines, and chemokines that disrupt antitumor immunity.48 CAF, cancer-associated fibroblasts; GM-CSF, granulocyte-macrophage colony-stimulating factor; Gr-MDSC, granulocytic MDSC; IL, interleukin; MDSC, myeloid-derived suppressor cell; Mo-MDSC, monocytic MDSC; PD-L1, programmed death ligand-1; PDAC, pancreatic ductal adenocarcinoma; TAM, tumor-associated macrophage; TGF, transforming growth factor; Treg, regulatory T-cell; VEGF, vascular endothelial growth factor.