Figure 2.

Diagrammatic representation of T cell suppressive effects of EV/exosomal PD-L1. Tumor cells and potentially other cells in the tumor microenvironment release extracellular vesicles including exosomes. These may carry PD-L1 depending on its expression status in the originating cell. PD-L1 is presented on the surface of EVs, where is can act systemically and locally to impair T cell activation via binding of PD1, and subsequent blockade of T cell receptor signaling and tumor cell killing.