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Tumor-Derived Exosomes Drive Immunosuppressive Macrophages In A Pre-Metastatic Niche Through Nf-Kβ Dependent Glycolytic Metabolic Reprogramming., Samantha M. Morrissey

Electronic Theses and Dissertations

The formation of a pre-metastatic niche is a fundamental requirement for primary tumor metastasis. One of the defining characteristics of a pre-metastatic niche is infiltration of immunosuppressive macrophages. However, how these macrophages acquire their immunosuppressive phenotype remains largely unexplored. Here, we demonstrate that tumor-derived exosomes (TDE) polarize macrophages towards an immunosuppressive phenotype characterized by increased PD-L1 expression through NF-kB-dependent metabolic reprogramming in mice and humans. While NF-κB has previously been shown to act as a direct transcription factor for PD-L1, we report a novel mechanism where TDE-induced NF-κB activation drives PD-L1 expression by augmenting the glycolytic capacity of macrophages through …