Abstract:
Fish, comprising over 27,000 species, represent the oldest vertebrate group and possess both innate and adaptive immune systems. The susceptibility of most wild fish to parasitic infections and related diseases is well-established. Among all vertebrates, the digestive tract creates a remarkably favorable and nutrient-rich environment, which, in turn, renders it susceptible to microparasites and macroparasites. Consequently, metazoan parasites emerge as important disease agents, impacting both wild and farmed fish and resulting in substantial economic losses. Given their status as pathogenic organisms, these parasites warrant considerable attention. Helminths, a general term encompassing worms, constitute one of the most important groups of metazoan parasites in fish. This group includes various species of platyhelminthes (digeneans, cestodes), nematodes, and acanthocephalans. In addition, myxozoans, microscopic metazoan endoparasites, are found in water-dwelling invertebrates and vertebrate hosts. It is worth noting that several innate immune cells within the fish alimentary canal and certain visceral organs (e.g., liver, spleen, and gonads) play active roles in the immune response against parasites. These immune cells include macrophages, neutrophils, rodlet cells, and mast cells also known as eosinophilic granular cells. At the site of intestinal infection, helminths often impact mucous cells number and alter mucus composition. This paper presents an overview of the state of the art on the occurrence and characteristics of innate immune cells in the digestive tract and other visceral organs in different fish-parasite systems. The data, coming especially from studies employed immunohistochemical, histopathological, and ultrastructural analyses, provide evidence supporting the involvement of teleost innate immune cells in modulating inflammatory responses to metazoan and protozoan parasitic infections.
摘要:
鱼,包括超过27,000个物种,代表最古老的脊椎动物群体,拥有先天和适应性免疫系统。大多数野生鱼类对寄生虫感染和相关疾病的易感性是公认的。在所有脊椎动物中,消化道创造了一个非常有利和营养丰富的环境,which,反过来,使其对微寄生虫和大型寄生虫敏感。因此,后生寄生虫作为重要的疾病因子出现,影响野生和养殖鱼类,造成巨大的经济损失。鉴于它们作为病原生物的地位,这些寄生虫值得相当关注。蠕虫,包含蠕虫的一般术语,构成鱼类中最重要的后生动物寄生虫群之一。该组包括各种鸭嘴兽(双族,cestodes),线虫,和棘头动物。此外,粘液虫,微观后生动物内寄生虫,在居住在水中的无脊椎动物和脊椎动物宿主中发现。值得注意的是,鱼类消化道和某些内脏器官内的几种先天免疫细胞(例如,肝脏,脾,脾和性腺)在针对寄生虫的免疫反应中发挥积极作用。这些免疫细胞包括巨噬细胞,中性粒细胞,Rodlet细胞,肥大细胞也称为嗜酸性粒细胞。在肠道感染部位,蠕虫通常会影响粘液细胞数量并改变粘液组成。本文概述了不同鱼类寄生虫系统中消化道和其他内脏器官中先天免疫细胞的发生和特征。数据,特别是来自免疫组织化学的研究,组织病理学,和超微结构分析,提供证据支持硬骨鱼先天免疫细胞参与调节后生动物和原生动物寄生虫感染的炎症反应。