IgA is produced in large quantities at mucosal surfaces by IgA⁺ plasma cells (PC), protecting the host from pathogens, and restricting commensal access to the subepithelium. It is becoming increasingly appreciated that IgA⁺ PC are not constrained to mucosal barrier sites. Rather, IgA⁺ PC may leave these sites where they provide both host defense and immunoregulatory function. In this review, we will outline how IgA⁺ PC are generated within the mucosae and how they subsequently migrate to their “classical” effector site, the gut lamina propria. From there we provide examples of IgA⁺ PC displacement from the gut to other parts of the body, referencing examples during homeostasis and inflammation. Lastly, we will speculate on mechanisms of IgA⁺ PC displacement to other tissues. Our aim is to provide a new perspective on how IgA⁺ PC are truly fantastic beasts of the immune system and identify new places to find them.

中文翻译：

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神奇的 IgA 浆细胞以及在哪里可以找到它们

IgA 由 IgA ⁺浆细胞 (PC)在粘膜表面大量产生，保护宿主免受病原体侵害，并限制共生进入上皮下。人们越来越认识到 IgA ⁺ PC 不受粘膜屏障位点的限制。相反，IgA ⁺ PC 可能会离开这些位点，在那里它们提供宿主防御和免疫调节功能。在这篇综述中，我们将概述 IgA ⁺ PC如何在粘膜内产生，以及它们如何随后迁移到它们的“经典”效应部位，即肠道固有层。从那里我们提供了 IgA ^{+ 的}例子PC 从肠道转移到身体其他部位，参考体内平衡和炎症期间的例子。最后，我们将推测 IgA ⁺ PC 置换到其他组织的机制。我们的目标是提供一个新的视角，了解 IgA ⁺ PC如何真正成为免疫系统的神奇野兽，并确定可以找到它们的新位置。