The Immunomechanical Checkpoint PYK2 Governs Monocyte-to-Macrophage Differentiation in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is characterized by a fibrotic, stiff tumor microenvironment in which tumor-associated macrophages (TAM) drive extracellular matrix remodeling, progression, and immune evasion. The contribution of mechanical cues to monocyte differentiation into TAMs remains largely unexplored. In this study, we show that mechanical force is required for monocyte-to-macrophage differentiation. PYK2, as an immunomechanical checkpoint, de facto governs this differentiation process. We demonstrated that PYK2 senses mechanical signals via PIEZO1 and integrins, triggering F-actin polymerization and translocating to the nucleus to regulate mechanotransduction and differentiation genes (e.g., ACTR3, RELA). Targeted deletion of Ptk2b, which encodes PYK2 impairs the differentiation and polarization of monocyte-derived macrophages, reshapes the PDAC microenvironment, and enhances the efficacy of anti-PD-1 immunotherapy. These findings underscore the critical role of mechanical cues in monocyte differentiation and suggest that targeting PYK2 is a promising strategy to modulate TAM function and improve immunotherapy outcomes in patients with PDAC. SIGNIFICANCE: This study identifies PYK2 as an immunomechanical checkpoint that drives monocyte-to-macrophage differentiation in PDAC via PIEZO1/integrin-mediated mechanical cues. Targeted deletion of Ptk2b (PYK2) reshapes the PDAC microenvironment and enhances the efficacy of anti-PD-1 immunotherapy, suggesting PYK2 as a promising therapeutic target to overcome immunotherapy resistance.