Table 2.
The effects of extracellular vesicle PD-L1 on tumor cells
| Type of tumor | Target cell | Effect | References |
|---|---|---|---|
| Direct effects | |||
| Prostate cancer | CD4+/CD8+T cells | Inhibition of T-cell activation and activity; the percentage of the depletion marker Tim3 increased, while that of the activation marker granzyme B percentage decreased | [9] |
| Melanoma | CD8+T cells | Inhibited the proliferation, cytokine production and cytotoxicity of CD8+T cells | [8] |
| Breast cancer | T cells | Inhibited the indicators of T-cell activation, such as NF-κB activation, as well as PHA-induced interleukin 2 (IL-2) secretion | [123] |
| Head and neck cancer | CD8+T cells | Inhibited the expression of CD69 (a marker of T-cell activation) | [124] |
| Pancreatic cancer | Exo-PD-L1 expression negatively correlated with postoperative survival time in patients with pancreatic ductal adenocarcinoma | [125] | |
| Glioblastoma | CD4+/CD8+T cells | The expression of CD69 and CD25 and proliferative ability in CD4+ and CD8+ T cells decreased | [114] |
| Gastric cancer | CD4+/CD8+T cells | Inhibition of T-cell proliferation and negative correlation with granzyme B | [126] |
| Non-small cell lung cancer | Jurkat cells/CD8+T cells | Decreased the production of INF-γ and induced apoptosis | [127] |
| Indirect effects | |||
| Glioblastoma | Monocytes | Extracellular vesicles of gastric cancer cells induce PD-L1 expression on neutrophils to inhibit T-cell-mediated immunity | [133] |
| Gastric cancer | Neutrophils | EVs of gastric cancer cells induce PD-L1 expression on neutrophils to inhibit T cell immunity | [134] |
| Chronic lymphocytic leukemia | Monocytes | CLL-derived exosomes increased PD-L1 expression; increased CCL2, CCL4, and IL-6 secretion from monocytes | [138] |
| Liver Cancer | Macrophages | Hepatoma cells release mir-23a-3p-containing exosomes and upregulate the expression of PD-L1 in macrophages, thereby reducing the ratio of CD8+ T cells and promoting T-cell apoptosis | [139] |
| Non-small cell lung cancer | Macrophages | Exosomes derived from non-small cell lung cancer cells promote the expression of PD-L1 on the surface of macrophages, and then inhibit tumor immunity | [137] |