Piazzon Maria C, Galindo-Villegas Jorge, Pereiro Patricia, Estensoro Itziar, Calduch-Giner Josep A, Gómez-Casado Eduardo, Novoa Beatriz, Mulero Victoriano, Sitjà-Bobadilla Ariadna, Pérez-Sánchez Jaume
Instituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC) , Castellón , Spain.
Department of Cell Biology and Histology, Faculty of Biology, Biomedical Research Institute of Murcia (IMIB-Arrixaca-UMU), University of Murcia , Murcia , Spain.
Front Immunol. 2016 Dec 27;7:637. doi: 10.3389/fimmu.2016.00637. eCollection 2016.
Three different immunoglobulin (Ig) isotypes can be found in teleost fish, IgM, IgD, and the teleost-specific IgT. IgM is considered to have a systemic activity, and IgT is attributed a mucosal role, similar to mammalian IgA. In this study, the complete sequence of gilthead sea bream IgM and IgT in their membrane (m) and soluble (s) forms are described for the first time in a perciform fish. Their constitutive gene expression is analyzed in different tissues, and their regulation upon viral, bacterial, parasitic, mucosal vaccination and dietary challenges are studied. GCB IgM and IgT have the prototypical structure when compared to other fish Igs. The constitutive expression of was the highest overall in all tissues, whereas expression was highest in mucosal tissues, such as gills and intestine. and were differentially regulated upon infection. was highly upregulated locally upon infection with the intestinal parasite or systemically after Nodavirus infection. Long-term intestinal parasitic infections increased the serum titer of both isotypes. Mucosal vaccination against subsp. finely regulated the Ig response inducing a systemic increase of IgM titers in serum and a local IgT response in skin mucus when animals were exposed to the pathogen by bath challenge. Interestingly, plant-based diets inhibit IgT upregulation upon intestinal parasitic challenge, which was related to a worse disease outcome. All these results corroborate the mucosal role of IgT and emphasize the importance of a finely tuned regulation of Ig isotypes upon infection, which could be of special interest in vaccination studies.
硬骨鱼中可发现三种不同的免疫球蛋白（Ig）同种型，即IgM、IgD和硬骨鱼特有的IgT。IgM被认为具有全身活性，而IgT被认为具有黏膜作用，类似于哺乳动物的IgA。在本研究中，首次在鲈形目鱼类中描述了金头鲷IgM和IgT的膜（m）型和可溶性（s）型的完整序列。分析了它们在不同组织中的组成型基因表达，并研究了它们在病毒、细菌、寄生虫、黏膜疫苗接种和饮食刺激下的调控情况。与其他鱼类Ig相比，金头鲷IgM和IgT具有典型结构。[此处原文缺失两种Ig的具体指代，无法准确翻译]在所有组织中的组成型表达总体上最高，而[此处原文缺失Ig的具体指代，无法准确翻译]在鳃和肠道等黏膜组织中的表达最高。[此处原文缺失两种Ig的具体指代，无法准确翻译]在感染后受到不同调控。感染肠道寄生虫[此处原文缺失寄生虫名称，无法准确翻译]后，[此处原文缺失Ig的具体指代，无法准确翻译]在局部高度上调，而感染诺达病毒后则在全身上调。长期肠道寄生虫感染会增加两种同种型的血清滴度。针对[此处原文缺失亚种名称，无法准确翻译]亚种的黏膜疫苗接种精细调节了Ig反应，当动物通过浸浴攻击暴露于病原体时，诱导血清中IgM滴度系统性增加以及皮肤黏液中局部IgT反应。有趣的是，植物性饮食会抑制肠道寄生虫攻击时IgT的上调，这与更差的疾病结果有关。所有这些结果证实了IgT的黏膜作用，并强调了感染时对Ig同种型进行精细调节的重要性，这在疫苗接种研究中可能特别有意义。
