The Role of Tumor-Derived Exosomes (TEX) in Shaping Anti-Tumor Immune Competence

Emerging studies suggest that extracellular vesicles (EVs) mediating intercellular communication in the tumor microenvironment (TME) play a key role in driving cancer progression. Tumor-derived small EVs or exosomes (TEX) enriched in immunosuppressive proteins or in microRNAs targeting suppressive pathways in recipient cells contribute to reprogramming the TME into a cancer-promoting milieu. The adenosinergic pathway is an acknowledged major contributor to tumor-induced immune suppression. TEX carry the components of this pathway and utilize ATP to produce adenosine (ADO). TEX-associated ADO emerges as a key factor in the suppression of T cell responses to therapy. Here, the significance of the ADO pathway in TEX is discussed as a highly effective mechanism of cancer-driven immune cell suppression and of resistance to immune therapies.