Figure 1.

Role of exosomes in tumor microenvironment

After EV uptake, interferon (IFN) β induces IFN stimulating genes in recipient macrophages via IFN α/β receptors, and it can induce monocytes to differentiate into macrophages, which can extend the life span of cancer patients. TDE increases PD-L1 expression through NF-κB-dependent glycolytic-led metabolic reprogramming, and promotes glucose to lactate conversion through the PKM pathway via TLR2, the lactic acid is increased, lactic acid further feeds back NF-κB, thereby increasing PD-L1, thereby polarizing macrophages to an immunosuppressive phenotype.