Valero Yulema, García-Alcázar Alicia, Esteban M Ángeles, Cuesta Alberto, Chaves-Pozo Elena
Centro Oceanográfico de Murcia, Instituto Español de Oceanografía (IEO), Carretera de la Azohía s/n. Puerto de Mazarrón, 30860 Murcia, Spain.
Department of Cell Biology and Histology, Faculty of Biology, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, 30100 Murcia, Spain.
Fish Shellfish Immunol. 2015 May;44(1):203-13. doi: 10.1016/j.fsi.2015.02.015. Epub 2015 Feb 21.
Antimicrobial peptides (AMPs) have a crucial role in the fish innate immune response, being considered a fundamental component of the first line of defence against pathogens. Moreover, AMPs have not been studied in the fish gonad since this is used by some pathogens as a vehicle or a reservoir to be transmitted to the progeny, as occurs with nodavirus (VNNV), which shows vertical transmission through the gonad and/or gonadal fluids, but no study has looked into the gonad of infected fish. In this framework, we have characterized the antimicrobial response triggered by VNNV in the testis of European sea bass, a very susceptible species of the virus, and in the gilthead seabream, which acts as a reservoir, both in vivo and in vitro, and compared with that present in the serum and brain (target tissue of VNNV). First, our data show a great antiviral response in the brain of gilthead seabream and in the gonad of European sea bass. In addition, for the first time, our results demonstrate that the antimicrobial activities (complement, lysozyme and bactericidal) and the expression of AMP genes such as complement factor 3 (c3), lysozyme (lyz), hepcidin (hamp), dicentracin (dic), piscidin (pis) or β-defensin (bdef) in the gonad of both species are very different, but generally activated in the European sea bass, probably related with the differences of susceptibility upon VNNV infection, and even differs to the brain response. Furthermore, the in vitro data suggest that some AMPs are locally regulated playing a local immune response in the gonad, while others are more dependent of the systemic immune system. Data are discussed in the light to ascertain their potential role in viral clearance by the gonad to avoid vertical transmission.
抗菌肽（AMPs）在鱼类先天免疫反应中起着关键作用，被认为是抵御病原体的第一道防线的基本组成部分。此外，尚未在鱼类性腺中对抗菌肽进行研究，因为一些病原体将其用作传播给后代的载体或储存库，如诺达病毒（VNNV），它通过性腺和/或性腺液进行垂直传播，但尚无研究调查受感染鱼类的性腺。在此框架下，我们对欧洲海鲈（该病毒的一个非常易感物种）和作为储存库的金头鲷的睾丸中由VNNV引发的抗菌反应进行了体内和体外表征，并与血清和大脑（VNNV的靶组织）中的反应进行了比较。首先，我们的数据显示金头鲷大脑和欧洲海鲈性腺中存在强烈的抗病毒反应。此外，我们的结果首次表明，这两个物种性腺中的抗菌活性（补体、溶菌酶和杀菌活性）以及补体因子3（c3）、溶菌酶（lyz）、铁调素（hamp）、双心杀菌素（dic）、鱼杀菌肽（pis）或β-防御素（bdef）等抗菌肽基因的表达差异很大，但在欧洲海鲈中通常被激活，这可能与VNNV感染的易感性差异有关，甚至与大脑反应也不同。此外，体外数据表明，一些抗菌肽受到局部调节，在性腺中发挥局部免疫反应，而另一些则更依赖于全身免疫系统。我们根据这些数据讨论了它们在性腺清除病毒以避免垂直传播方面的潜在作用。
