Macrophages foster anti-tumor immunity by ZEB1-dependent cytotoxic T cell chemoattraction.

Tumor-associated macrophages (TAMs) dynamically influence anti-tumor immunity. Understanding TAM function is therefore critical to design immunotherapies. By combining syngeneic models of colorectal and pancreatic cancer with cell type-specific deletion of the epithelial-to-mesenchymal transition driver Zeb1, which is expressed in subsets of TAMs, we discovered that ZEB1 is an intrinsic regulator of TAM-controlled T cell trafficking and anti-tumor immune responses. ZEB1 supports secretion of a subset of chemokines via the constitutive pathway, including CXCL10, CCL2 and CCL22, by regulating their biosynthesis, vesicular transport and release. This elevates cytotoxic T cell (CTL) recruitment in vitro and fosters immunosurveillance by CTLs in tumors and metastases as well in an organotypic model for therapeutic CD8 + T cell addition. Our study identifies ZEB1 in TAMs as a facilitator of anti-tumor immunity, suggests a window of opportunity for cytokine-guided CTL tropism and reinforces the importance of onco-immunological context, particularly in the design of macrophage- and/or cytokine-depleting strategies.