Laboratory of Molecular Genetics, Department of Biotechnology and Bioindustry Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan 70101, Taiwan; Laboratory of Molecular Genetics, Institute of Biotechnology, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan 70101, Taiwan.
Laboratory of Molecular Genetics, Institute of Biotechnology, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan 70101, Taiwan.
Fish Shellfish Immunol. 2018 Mar;74:551-558. doi: 10.1016/j.fsi.2018.01.029.
Viral nervous necrosis caused by nervous necrosis virus (NNV) is one of the most severe diseases resulting in high fish mortality rates and high economic losses in the giant grouper industry. Various NNV vaccines have been evaluated, such as inactivated viruses, virus-like particles (VLPs), recombinant coat proteins, synthetic peptides of coat proteins, and DNA vaccines. However, a cheaper manufacturing process and effective protection of NNV vaccines for commercial application are yet to be established. Hence, the present study developed a novel subunit vaccine composed of a carrier protein, receptor-binding domain of Pseudomonas exotoxin A, and tandem-repeated NNV coat protein epitopes by using the structural basis of epitope prediction and the linear array epitope (LAE) technique. On the basis of the crystal structure of the NNV coat protein, the epitope was predicted from the putative target cell receptor-binding region to elicit neutralizing immune responses. The safety of the LAE vaccine was evaluated, and all vaccinated fish survived without any physiological changes. The coat protein-specific antibody titers in the vaccinated fish increased after vaccine administration and exerted NNV-neutralizing effects. The efficacy tests revealed that the relative percent survival (RPS) of LAE antigen formulated with adjuvant was above 72% and LAE vaccine was effective for preventing NNV infection in giant grouper. This study is the first to develop an NNV vaccine by using epitope repeats, which provided effective protection to giant grouper against virus infection. The LAE construct can be used as a vaccine design platform against various pathogenic diseases.
神经坏死病毒（NNV）引起的病毒性神经坏死病是导致巨型石斑鱼产业中鱼类死亡率高和经济损失大的最严重疾病之一。已经评估了各种 NNV 疫苗，如灭活病毒、病毒样颗粒（VLPs）、重组外壳蛋白、外壳蛋白的合成肽和 DNA 疫苗。然而，一种更便宜的制造工艺和对 NNV 疫苗的有效保护，以便商业应用，尚未建立。因此，本研究开发了一种新型亚单位疫苗，该疫苗由载体蛋白、假单胞菌外毒素 A 的受体结合结构域和串联重复的 NNV 外壳蛋白表位组成，使用了表位预测的结构基础和线性阵列表位（LAE）技术。基于 NNV 外壳蛋白的晶体结构，从假定的靶细胞受体结合区域预测表位，以引发中和免疫反应。评估了 LAE 疫苗的安全性，所有接种疫苗的鱼都存活下来，没有任何生理变化。接种疫苗后，鱼体内的外壳蛋白特异性抗体滴度增加，并产生 NNV 中和作用。功效测试表明，用佐剂配制的 LAE 抗原的相对存活率（RPS）高于 72%，LAE 疫苗可有效预防巨型石斑鱼感染 NNV。本研究首次利用表位重复开发了 NNV 疫苗，为巨型石斑鱼提供了针对病毒感染的有效保护。LAE 构建体可作为针对各种致病性疾病的疫苗设计平台。
