Harnessing EV communication to restore antitumor immunity

Restoring effective anti-tumor immune responses to cure cancer is a promising strategy, but challenging to achieve due to the intricate crosstalk between tumor and immune cells. While it is established that tumor cells acquire traits to escape immune recognition, the involvement of extracellular vesicles (EVs) in curbing immune cell activation is rapidly emerging. By assisting cancer cells in spreading immunomodulatory signals in the form of (glyco)proteins, lipids, nucleic acids and metabolic regulators, EVs recently emerged as versatile mediators of immune suppression. Blocking their action might reactivate immune cell function and natural antitumor immune responses. Alternatively, EV communication may be exploited to boost anti-tumor immunity. Indeed, novel insights into EV biology paved the way for efficient ex vivo production of 'rationally engineered' EVs that function as potent antitumor vaccines or carry out specific functional tasks. In this review we discuss the latest findings on immune regulation by cancer EVs and explore how EV-mediated communication can be either targeted or harnessed to restore immunity as a means for cancer therapy.