Xu Zhen, Takizawa Fumio, Parra David, Gómez Daniela, von Gersdorff Jørgensen Louise, LaPatra Scott E, Sunyer J Oriol
Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, 413 Rosenthal building, 3800 Spruce Street, Philadelphia, Pennsylvania 19104, USA.
Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
Nat Commun. 2016 Feb 12;7:10728. doi: 10.1038/ncomms10728.
Gas-exchange structures are critical for acquiring oxygen, but they also represent portals for pathogen entry. Local mucosal immunoglobulin responses against pathogens in specialized respiratory organs have only been described in tetrapods. Since fish gills are considered a mucosal surface, we hypothesized that a dedicated mucosal immunoglobulin response would be generated within its mucosa on microbial exposure. Supporting this hypothesis, here we demonstrate that following pathogen exposure, IgT(+) B cells proliferate and generate pathogen-specific IgT within the gills of fish, thus providing the first example of locally induced immunoglobulin in the mucosa of a cold-blooded species. Moreover, we demonstrate that gill microbiota is predominantly coated with IgT, thus providing previously unappreciated evidence that the microbiota present at a respiratory surface of a vertebrate is recognized by a mucosal immunoglobulin. Our findings indicate that respiratory surfaces and mucosal immunoglobulins are part of an ancient association that predates the emergence of tetrapods.
气体交换结构对于获取氧气至关重要，但它们也构成了病原体进入的通道。针对特殊呼吸器官中病原体的局部黏膜免疫球蛋白反应仅在四足动物中有所描述。由于鱼鳃被视为黏膜表面，我们推测在接触微生物时，其黏膜内会产生专门的黏膜免疫球蛋白反应。为支持这一假设，我们在此证明，病原体暴露后，IgT(+) B细胞在鱼鳃内增殖并产生病原体特异性IgT，从而提供了冷血动物黏膜中局部诱导免疫球蛋白的首个实例。此外，我们证明鳃微生物群主要被IgT覆盖，从而提供了此前未被认识到的证据，即脊椎动物呼吸表面存在的微生物群被黏膜免疫球蛋白所识别。我们的研究结果表明，呼吸表面和黏膜免疫球蛋白是四足动物出现之前就已存在的古老关联的一部分。
