肝移植（LT）是终末期肝病或早期肝细胞癌患者的最终治疗方法。在LT方面，由于人同种异体肝脏移植物独特的免疫学特征，5%-20%的选定LT接受者可以实现操作耐受。尽管如此，LT 患者仍然存在排斥的风险。因此，维持免疫稳态对于改善这些患者的临床结果至关重要。在机制上，包括树突状细胞、库普弗细胞、骨髓源性抑制细胞、肝星状细胞、调节性 B 细胞和 CD4 调节性 T 细胞 (Treg) 在内的多种免疫细胞有助于在 LT 后实现耐受。就 Treg 而言，它在成功最小化免疫抑制或实现 LT 后耐受性方面发挥着作用，同时还降低了排斥风险。此外，肠道微生物组沿着肠-肝轴调节全身免疫功能。最近的研究探索了微生物组及其代谢物在各种条件下的变化，包括 LT 后、急性排斥和耐受。某些功能性微生物组和代谢物表现出免疫调节功能，例如 Treg 的增强，影响免疫稳态。因此，了解 LT 的耐受机制、Treg 在耐受和排斥中的作用以及它们与肠道微生物组的相互作用对于 LT 患者的管理至关重要。版权所有 © 2024 Wolters Kluwer Health, Inc. 保留所有权利。

Liver transplantation (LT) is the ultimate treatment for patients with end-stage liver disease or early hepatocellular carcinoma. In the context of LT, because of the unique immunological characteristics of human liver allograft, 5%-20% of selected LT recipients can achieve operational tolerance. Nonetheless, there remains a risk of rejection in LT patients. Maintaining immune homeostasis is thus crucial for improving clinical outcomes in these patients. In mechanism, several immune cells, including dendritic cells, Kupffer cells, myeloid-derived suppressor cells, hepatic stellate cells, regulatory B cells, and CD4+ regulatory T cells (Treg), contribute to achieving tolerance following LT. In terms of Treg, it plays a role in successfully minimizing immunosuppression or achieving tolerance post-LT while also reducing the risk of rejection. Furthermore, the gut microbiome modulates systemic immune functions along the gut-liver axis. Recent studies have explored changes in the microbiome and its metabolites under various conditions, including post-LT, acute rejection, and tolerance. Certain functional microbiomes and metabolites exhibit immunomodulatory functions, such as the augmentation of Treg, influencing immune homeostasis. Therefore, understanding the mechanisms of tolerance in LT, the role of Treg in tolerance and rejection, as well as their interactions with gut microbiome, is vital for the management of LT patients.Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.