三级淋巴器官（TLO），也称为三级或异位淋巴结构或组织，是典型淋巴器官以外部位的淋巴细胞聚集，是在自身免疫、微生物感染、癌症、衰老和慢性炎症过程中通过淋巴新生而产生的。移植，是本次综述的重点。比较淋巴结和 TLO 的细胞组成、组织、血管成分和迁移信号调节。移植后 TLO (PT-TLO) 的这些特征通过各种器官中的个别例子进行了描述，包括心脏、肾脏、气管、肺、动脉、皮肤、腿部、手和面部，以及许多物种（包括人类、小鼠、大鼠）和猴子。诱导和维持 TLO 的要求包括持续暴露于自身抗原、同种异体抗原、肿瘤抗原、缺血再灌注、肾毒性药物和衰老。关于它们在器官排斥中的功能，已经提出了几种分期方案。 PT-TLO 通常与器官排斥有关，但在某些情况下有助于耐受。 PT-TLO 在癌症中的作用是在免疫抑制的情况下考虑的。此外，TLO 可能与淋巴瘤的发生有关。 PT-TLO 研究面临的挑战涉及分期、影像学以及抑制排斥和鼓励耐受的治疗操作机会。版权所有 © 2023 作者。由 Wolters Kluwer Health, Inc. 出版

Tertiary lymphoid organs (TLOs), also known as tertiary or ectopic lymphoid structures or tissues, are accumulations of lymphoid cells in sites other than canonical lymphoid organs, that arise through lymphoid neogenesis during chronic inflammation in autoimmunity, microbial infection, cancer, aging, and transplantation, the focus of this review. Lymph nodes and TLOs are compared regarding their cellular composition, organization, vascular components, and migratory signal regulation. These characteristics of posttransplant TLOs (PT-TLOs) are described with individual examples in a wide range of organs including heart, kidney, trachea, lung, artery, skin, leg, hand, and face, in many species including human, mouse, rat, and monkey. The requirements for induction and maintenance of TLOs include sustained exposure to autoantigens, alloantigens, tumor antigens, ischemic reperfusion, nephrotoxic agents, and aging. Several staging schemes have been put forth regarding their function in organ rejection. PT-TLOs most often are associated with organ rejection, but in some cases contribute to tolerance. The role of PT-TLOs in cancer is considered in the case of immunosuppression. Furthermore, TLOs can be associated with development of lymphomas. Challenges for PT-TLO research are considered regarding staging, imaging, and opportunities for their therapeutic manipulation to inhibit rejection and encourage tolerance.Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc.