Tumor-derived exosomes (TEX) are involved in cancer development, metastasis, and disease progression. They can modulate angiogenesis to elevate the malignant degree of tumor cells. TEX carry immunosuppressive factors affecting the antitumor activities of immune cells. Tumor cells as well as immune cells secrete immunologically active exosomes which affect intercellular communication, antigen presentation, activation of immune cells, and immune surveillance. Cell proliferation and immune response suppression create a favorable microenvironment for tumor. TEX can inhibit immune cell proliferation, induce apoptosis of activated CD8+ Teffs, suppress NK cell activity, interfere with monocyte differentiation, and promote Treg as well as MDSC expansion. Exosomes of microenvironment cells may also contribute to the development of drug resistance in cancer therapy. An important role of TEX in modulating the sensitivity of tumor cells to immunotherapy is a promising area of research to make the cancer therapy more successful.

中文翻译：

---

免疫抑制和免疫治疗中的肿瘤衍生外来体。

肿瘤来源的外来体（TEX）参与癌症的发展，转移和疾病的发展。它们可以调节血管生成以提高肿瘤细胞的恶性程度。TEX带有影响免疫细胞抗肿瘤活性的免疫抑制因子。肿瘤细胞和免疫细胞分泌具有免疫活性的外来体，这些外来体会影响细胞间的通讯，抗原呈递，免疫细胞的活化和免疫监视。细胞增殖和免疫应答抑制为肿瘤创造了良好的微环境。TEX可以抑制免疫细胞增殖，诱导活化的CD8 + Teffs凋亡，抑制NK细胞活性，干扰单核细胞分化，并促进Treg和MDSC扩增。微环境细胞的外来体也可能有助于癌症治疗中耐药性的发展。TEX在调节肿瘤细胞对免疫疗法的敏感性中的重要作用是使癌症疗法更加成功的有前途的研究领域。