Strategies to Target the Tumor-Associated Macrophages in the Immunosuppressive Microenvironment of Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is a critical disease requiring the development of novel effective therapeutic approaches due to its increasing global incidence and associated low survival rates. While immunotherapy, including immune checkpoint inhibitors, has shown efficacy against various tumors, developing an effective treatment approach for PDAC poses a challenge. This is primarily attributed to the complex and distinctive immune evasion mechanisms of PDAC. Recent studies have revealed that tumor-associated macrophages (TAMs) play a crucial role in enhancing immune evasion in PDAC. This role is mediated through multiple pathways, including cytokine secretion and the activation or suppression of diverse immune cells. A clear understanding of how macrophages contribute to PDAC proliferation could lead to the development of novel immune therapy approaches targeting TAMs. In this review, we summarized the multifaceted activities and roles of TAMs in PDAC and explored the potential effect of immunotherapeutic approaches on PDAC, with a particular focus on chimeric antigen receptor (CAR) macrophages. This review was based on promising findings from recent studies on CAR macrophage-based immunotherapy for solid tumors.