Fig. 3.

Immune evasion orchestrated by pancreatic cancer cells and stromal cells. The secretion and immunomodulation of pro-tumorigenic cytokines by pancreatic cancer cells and stromal cells are tightly regulated by oncogenic KRAS- or mutant TP53-dependent pathways. Pancreatic cancer cells secrete cytokines and, chemokines and recruit immunosuppressive cells, including MDSCs, TAMs, Treg cells, and neutrophils, which suppress the activity and functions of CD8⁺ cytotoxic T cells. Pancreatic cancer cells also evade the immune system by expressing PDL-1 to promote CD8⁺ T cell exhaustion. Immune cell infiltration also releases cytokines and growth factors that directly stimulate tumor growth by promoting angiogenesis and increasing the invasive ability of pancreatic cancer cells