Fish mucosal surface is a significant interface for pathogens to infect from an aqueous environment. In addition to mucosal innate and adaptive immune factors, epithelial cells are considered as a significant physical barrier against microbial invasion. Previously, we identified a mammalian CD46-like complement regulatory protein (Tecrem) in teleost and detected its expression on epithelial cells derived from fin, suggesting its physiological role on the fish surface. This study examines the homeostatic roles of Tecrem in maintaining the fish epithelium, by analyzing the expression behavior of Tecrem on the fin-derived epithelial cell lines (KF-1 from the common carp and CFS from ginbuna crucian carp) using monoclonal and polyclonal anti-Tecrem antibodies. Expression of KF-1 protein was associated with the adhesion of KF-1, and the adhesion was enhanced by anti-Tecrem treatments of the cells. Stimulation of the epithelial cells with anti-Tecrem enhanced wound healing, protein expression of tight-junction proteins, and cell density of the KF-1 and CFS monolayer culture. These results suggest that Tecrem on epithelial cells play a homeostatic role in maintaining intactness of the surface epithelial barrier, implying that modification of Tecrem expression may develop a novel tool to improve the first-line defense against pathogens in aquaculture.

中文翻译：

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Tecrem（一种 CD46 样补体激活调节蛋白）对鲤鱼上皮细胞的稳态功能

鱼类粘膜表面是病原体从水环境感染的重要界面。除了粘膜先天性和适应性免疫因素外，上皮细胞被认为是抵御微生物入侵的重要物理屏障。以前，我们在硬骨鱼中鉴定了一种哺乳动物 CD46 样补体调节蛋白 (Tecrem)，并检测了其在来自鳍的上皮细胞上的表达，表明其在鱼类表面上的生理作用。本研究通过使用单克隆和多克隆抗细胞因子分析 Tecrem 在鳍源上皮细胞系（鲤鱼的 KF-1 和银鲫的 CFS）上的表达行为，检验了 Tecrem 在维持鱼上皮细胞中的稳态作用。 Tecrem 抗体。KF-1 蛋白的表达与 KF-1 的粘附有关，并且通过细胞的抗 Tecrem 处理增强了粘附。用抗 Tecrem 刺激上皮细胞可增强伤口愈合、紧密连接蛋白的蛋白质表达以及 KF-1 和 CFS 单层培养物的细胞密度。这些结果表明上皮细胞上的 Tecrem 在维持表面上皮屏障的完整性方面发挥着稳态作用，这意味着 Tecrem 表达的修饰可能会开发一种新的工具来改善水产养殖中对病原体的一线防御。