Kim Jong-Oh, Kim Jae-Ok, Kim Wi-Sik, Oh Myung-Joo
Department of Aqualife Medicine, College of Fisheries and Ocean Science, Chonnam National University, Yeosu 550-749, Republic of Korea.
J Microbiol Biotechnol. 2015 Oct;25(10):1761-7. doi: 10.4014/jmb.1507.07004.
Sevenband grouper, Epinephelus septemfasciatus, is becoming an important aquaculture species in Korea. However, viral nervous necrosis disease is a large problem causing mass mortality in sevenband grouper aquaculture. Recombinant protein vaccines are one of the best methods to reduce these economic losses. However, the cell-based expression method mainly produces inclusion bodies and requires additional procedures. In this study, we expressed a recombinant viral coat protein of sevenband grouper nervous necrosis virus (NNV) using a cell-free protein synthesis system. The purified recombinant NNV coat protein (rNNV-CP) was injected into sevenband grouper at different doses followed by a NNV challenge. Nonimmunized fish in the first trial (20 μg/fish) began to die 5 days post-challenge and reached 70% cumulative mortality. In contrast, immunized fish also starting dying 5 days postchallenge but lower cumulative mortality (10%) was observed. Cumulative morality in the second trial with different doses (20, 4, and 0.8 μg/fish) was 10%, 40%, and 50%, respectively. These results suggest that rNNV-CP can effectively immunize sevenband grouper depending on the dose administered. This study provides a new approach to develop a recombinant vaccine against NNV infection for sevenband grouper.
七带石斑鱼（Epinephelus septemfasciatus）正成为韩国重要的水产养殖品种。然而，病毒性神经坏死病是七带石斑鱼水产养殖中导致大规模死亡的一个大问题。重组蛋白疫苗是减少这些经济损失的最佳方法之一。然而，基于细胞的表达方法主要产生包涵体，并且需要额外的步骤。在本研究中，我们使用无细胞蛋白质合成系统表达了七带石斑鱼神经坏死病毒（NNV）的重组病毒衣壳蛋白。将纯化的重组NNV衣壳蛋白（rNNV-CP）以不同剂量注射到七带石斑鱼体内，随后进行NNV攻毒。第一次试验中未免疫的鱼（20μg/鱼）在攻毒后5天开始死亡，累积死亡率达到70%。相比之下，免疫的鱼在攻毒后5天也开始死亡，但观察到较低的累积死亡率（10%）。第二次试验中不同剂量（20、4和0.8μg/鱼）的累积死亡率分别为10%、40%和50%。这些结果表明，rNNV-CP可以根据给药剂量有效地免疫七带石斑鱼。本研究为开发针对七带石斑鱼NNV感染的重组疫苗提供了一种新方法。
