The mucosal organs of fishes are directly exposed to their aquatic environment, which is suited to the colonization and growth of microorganisms, and thus these barriers are considered to play an important role in maintaining homeostasis and preventing entry of invasive pathogens. Research on fish mucosal immunity have shown that mucosal organs such as gills, skin, intestines and olfactory organs harbor lymphoid cells, including T and B cells as well as dendritic-like cells. Findings related to immune responses following direct administration of antigens into the mucosal organs could help to shed light upon the development of fish mucosal vaccines. The present review highlights vaccine delivery via mucosal organs, in particular focusing on methods other than those of typical mucosal vaccine platforms, such as oral and immersion vaccines. In addition, we propose the hypothesis that mucosal tissues are important sites for generating cell-mediated immunity following vaccination with extracellular antigens.

中文翻译：

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鱼疫苗的粘膜递送：粘膜免疫后的局部和全身免疫。

鱼类的粘膜器官直接暴露于适合微生物定植和生长的水生环境中，因此这些屏障被认为在维持体内平衡和防止侵入性病原体进入方面起着重要作用。对鱼类粘膜免疫的研究表明，粘膜器官（如腮，皮肤，肠和嗅觉器官）具有淋巴样细胞，包括T和B细胞以及树突状细胞。将抗原直接施用到粘膜器官后，与免疫反应相关的发现可能有助于阐明鱼粘膜疫苗的开发。本综述着重介绍了通过粘膜器官递送疫苗的方法，特别是针对典型的粘膜疫苗平台以外的方法，如口服和浸没疫苗。