[PDF][PDF] Tumor-derived exosomes drive immunosuppressive macrophages in a pre-metastatic niche through glycolytic dominant metabolic reprogramming

SM Morrissey, F Zhang, C Ding, DE Montoya-Durango… - Cell metabolism, 2021 - cell.com
SM Morrissey, F Zhang, C Ding, DE Montoya-Durango, X Hu, C Yang, Z Wang, F Yuan…
Cell metabolism, 2021cell.com
One of the defining characteristics of a pre-metastatic niche, a fundamental requirement for
primary tumor metastasis, is infiltration of immunosuppressive macrophages. How these
macrophages acquire their phenotype remains largely unexplored. Here, we demonstrate
that tumor-derived exosomes (TDEs) polarize macrophages toward an immunosuppressive
phenotype characterized by increased PD-L1 expression through NF-kB-dependent,
glycolytic-dominant metabolic reprogramming. TDE signaling through TLR2 and NF-κB …
Summary
One of the defining characteristics of a pre-metastatic niche, a fundamental requirement for primary tumor metastasis, is infiltration of immunosuppressive macrophages. How these macrophages acquire their phenotype remains largely unexplored. Here, we demonstrate that tumor-derived exosomes (TDEs) polarize macrophages toward an immunosuppressive phenotype characterized by increased PD-L1 expression through NF-kB-dependent, glycolytic-dominant metabolic reprogramming. TDE signaling through TLR2 and NF-κB leads to increased glucose uptake. TDEs also stimulate elevated NOS2, which inhibits mitochondrial oxidative phosphorylation resulting in increased conversion of pyruvate to lactate. Lactate feeds back on NF-κB, further increasing PD-L1. Analysis of metastasis-negative lymph nodes of non-small-cell lung cancer patients revealed that macrophage PD-L1 positively correlates with levels of GLUT-1 and vesicle release gene YKT6 from primary tumors. Collectively, our study provides a novel mechanism by which macrophages within a pre-metastatic niche acquire their immunosuppressive phenotype and identifies an important link among exosomes, metabolism, and metastasis.
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