外泌体是纳米级的细胞外囊泡，广泛存在于各种生物体液中。作为信使，外泌体传递来自供体细胞的特征性生物信息，促进它们的积累以及随后将信息转移到肿瘤免疫细胞。免疫疗法是癌症治疗的前沿策略，但由于严重的副作用和有限的疗效，尚未充分发挥其潜力。外泌体拥有抗原和免疫刺激分子，可以作为无细胞疫苗来诱导抗肿瘤免疫。此外，鉴于其稳定性、低免疫原性和靶向能力，外泌体通过递送货物（包括非编码核糖核酸（RNA）、膜蛋白、化疗剂和免疫细胞死亡诱导剂）而成为肿瘤免疫治疗中理想的药物递送系统。外泌体还可以被设计为精确靶向肿瘤细胞。然而，外泌体作为肿瘤免疫治疗的后起之秀，也受到一些挑战的阻碍，包括其分离和纯化缺乏统一的技术标准、需要提高外泌体负载量以实现外泌体的高效递送以及临床试验的扩大等。目前还处于起步阶段。未来需要长期、多中心、大规模的临床试验来评估外泌体的性能。尽管如此，外泌体在肿瘤免疫治疗中表现出了令人鼓舞的表现。在这篇综述中，我们总结了外泌体在肿瘤免疫治疗中的潜力和挑战，旨在阐明外泌体作为新时代肿瘤免疫治疗工具的作用。版权所有 © 2023 作者。由 Elsevier Masson SAS 出版。保留所有权利。

Exosomes are nano-scale extracellular vesicles that are found widely in various biological fluids. As messengers, exosomes deliver characteristic biological information from donor cells, facilitating their accumulation and subsequent transfer of information to tumor immune cells. Immunotherapy is a cutting-edge strategy for cancer therapy, but it has not yet reached its full potential owing to severe side effects and limited efficacy. Exosomes possess antigens and immunostimulatory molecules and can serve as cell-free vaccines to induce antitumor immunity. In addition, given their stability, low immunogenicity, and targeting ability, exosomes represent ideal drug delivery systems in tumor immunotherapy by delivering cargoes, including non-coding ribonucleic acids (RNAs), membrane proteins, chemotherapeutic agents, and immune cell death inducers. Exosomes can also be engineered to precisely target tumor cells. However, as a rising star in tumor immunotherapy, exosomes are also impeded by some challenges, including the lack of uniform technical standards for their isolation and purification, the need to improve exosomal cargo loading for efficient exosome delivery, and the expansion of clinical trials, which are currently in their infancy. Long-term, multi-center, and large-scale clinical trials are needed to evaluate the performance of exosomes in the future. Nonetheless, exosomes have demonstrated encouraging performance in tumor immunotherapy. In this review, we summarize the potential and challenges of exosomes in tumor immunotherapy, with the aim to shed light on exosomes as new-era tumor immunotherapy tools.Copyright © 2023 The Authors. Published by Elsevier Masson SAS.. All rights reserved.