目前大多数嵌合抗原受体（CAR）T细胞是通过病毒转导生成的，这会导致CAR的持续表达并可能引起严重的不良反应。正在开发基于信使RNA的方法来制造CAR T细胞以克服这些挑战。然而，向T细胞输送mRNA的最常用方法是电穿孔，这可能对细胞有毒。作者设计和构建了一个使用噬菌体MS2系统与外泌体上高表达的蛋白质溶酶体相关膜蛋白2同工酶B相结合的外泌体传递平台。作者的传递平台实现了对目标细胞的mRNA的特异性装载和传递，并实现了特定蛋白的表达，而抗CD3 / CD28单链变量片段（scFv）在外泌体膜外表达有效地激活了原代T细胞，类似于商业磁珠。通过设计的外泌体递送CAR mRNA和抗CD3 / CD28 scFv，可用于体外生产具有癌细胞杀伤能力的CAR T细胞。作者的结果表明，构建的外泌体递送平台具有直接将原代T细胞转化为CAR T细胞的潜在应用，并为体内生产CAR T细胞提供了一种新策略。版权所有©2023国际细胞和基因治疗协会。由Elsevier Inc.出版。保留所有权利。

Most current chimeric antigen receptor (CAR) T cells are generated by viral transduction, which induces persistent expression of CARs and may cause serious undesirable effects. Messenger RNA (mRNA)-based approaches in manufacturing CAR T cells are being developed to overcome these challenges. However, the most common method of delivering mRNA to T cells is electroporation, which can be toxic to cells.The authors designed and engineered an exosome delivery platform using the bacteriophage MS2 system in combination with the highly expressed protein lysosome-associated membrane protein 2 isoform B on exosomes.The authors' delivery platform achieved specific loading and delivery of mRNA into target cells and achieved expression of specific proteins, and anti-CD3/CD28 single-chain variable fragments (scFvs) expressed outside the exosomal membrane effectively activated primary T cells in a similar way to commercial magnetic beads.The delivery of CAR mRNA and anti-CD3/CD28 scFvs via designed exosomes can be used for ex vivo production of CAR T cells with cancer cell killing capacity. The authors' results indicate the potential applications of the engineered exosome delivery platform for direct conversion of primary T cells to CAR T cells while providing a novel strategy for producing CAR T cells in vivo.Copyright © 2023 International Society for Cell & Gene Therapy. Published by Elsevier Inc. All rights reserved.