Department of Cell Biology and Histology, Faculty of Biology, Campus Regional de Excelencia Internacional "Campus Mare Nostrum", University of Murcia, 30100 Murcia, Spain.
Centro Oceanográfico de Murcia, Instituto Español de Oceanografía (IEO), Carretera de la Azohía s/n, Puerto de Mazarrón, 30860 Murcia, Spain.
Fish Shellfish Immunol. 2014 Feb;36(2):545-51. doi: 10.1016/j.fsi.2014.01.001. Epub 2014 Jan 9.
Mucosal surfaces of fish, including skin, gill and gut, contain numerous immune substances poorly studied that act as the first line of defence against a broad spectrum of pathogens. This study aimed to identify and characterize for the first time different constitutive humoral defence mechanisms of the skin mucus of gilthead seabream (Sparus aurata). To do this, the levels of total immunoglobulin M, several enzymes and proteins (peroxidase, lysozyme, alkaline phosphatase, esterases, proteases and antiproteases), as well as the bactericidal activity against opportunist fish pathogens (Vibrio harveyi, Vibrio angillarum, Photobacterium damselae) and non-pathogenic bacteria (Escherichia coli, Bacillus subtilis) were measured in the skin mucus and compared with those found in the serum. This study demonstrates that gilthead seabream skin mucus contains lower levels of IgM, similar levels of lysozyme, alkaline phosphatase and proteases, and higher esterase, peroxidase and antiprotease activities than serum. In addition, skin mucus revealed stronger bactericidal activity against tested fish pathogen bacteria compared to the serum activity, while human bacteria can even grow more in the presence of mucus. The results could be useful for better understanding the role of the skin mucus as a key component of the innate immune system with potential application for the aquaculture.
鱼类的黏膜表面，包括皮肤、鳃和肠道，含有大量尚未充分研究的免疫物质，这些物质充当着抵御广谱病原体的第一道防线。本研究旨在首次鉴定和描述真鲷（Sparus aurata）皮肤黏液中不同的固有体液防御机制。为此，我们测量了皮肤黏液中总免疫球蛋白 M 以及几种酶和蛋白质（过氧化物酶、溶菌酶、碱性磷酸酶、酯酶、蛋白酶和抗蛋白酶）的水平，并比较了它们与血清中的水平。此外，还测量了皮肤黏液对机会性病原体（哈维氏弧菌、鳗弧菌、美人鱼发光杆菌）和非致病性细菌（大肠杆菌、枯草芽孢杆菌）的杀菌活性，并与血清中的杀菌活性进行了比较。本研究表明，与血清相比，真鲷皮肤黏液中的 IgM 水平较低，溶菌酶、碱性磷酸酶和蛋白酶水平相似，但酯酶、过氧化物酶和抗蛋白酶活性较高。此外，皮肤黏液对测试的鱼类病原体细菌的杀菌活性比血清中的杀菌活性更强，而在黏液存在的情况下，人类细菌甚至可以更旺盛地生长。这些结果有助于更好地理解皮肤黏液作为先天免疫系统关键组成部分的作用，具有水产养殖应用的潜力。
