Abstract

Ectopic lymphoid structures (ELS) or tertiary lymphoid organs are structures with the organization similar to the one of secondary lymphoid organs, formed in non-lymphoid tissues. They are considered to be an important site for the lymphocytic physiological and pathological role in conditions such are chronic infections, autoimmune diseases, cancer, and allograft rejection. Although similar to the secondary lymphoid tissues, the initiation of ELS formation is not preprogramed and requires chronic inflammation, expression of homeostatic chemokines, and lymphotoxin beta receptor activation. Importantly, while ELS formation may be considered beneficiary in antimicrobial and antitumor immunity, the persistence of these active lymphoid structures within the tissue increase the chance for development of autoimmunity and lymphoma. This paper is providing an overview of biological mechanisms involved in ELS formation, as well as the overview of the pathophysiological role of these structures. In addition, the paper discusses the possibility to therapeutically target ELS formation, bearing in mind their bivalent nature and role in different pathophysiological conditions.

摘要

异位淋巴结构 (ELS) 或三级淋巴器官是组织类似于二级淋巴器官之一的结构，在非淋巴组织中形成。它们被认为是在慢性感染、自身免疫性疾病、癌症和同种异体移植排斥等疾病中发挥淋巴细胞生理和病理作用的重要部位。虽然类似于次级淋巴组织，但 ELS 形成的启动不是预先编程的，需要慢性炎症、稳态趋化因子的表达和淋巴毒素 β 受体激活。重要的是，虽然 ELS 的形成可能被认为有利于抗菌和抗肿瘤免疫，但组织内这些活跃的淋巴结构的持续存在增加了自身免疫和淋巴瘤发展的机会。本文概述了 ELS 形成所涉及的生物学机制，以及这些结构的病理生理作用的概述。此外，本文讨论了治疗靶向 ELS 形成的可能性，同时牢记它们的二价性质和在不同病理生理条件下的作用。