周伟东+周勇+刘奕+张立强+邓平+艾桃山+曾令兵+喻运珍+喻婷

摘要：以ISKNV MCP基因为目的基因，克隆到真核表达质粒pcDNA3.1（+）中，构建成DNA疫苗pcMCP，对鳜鱼（Siniperca chuatsi）pcMCP DNA疫苗进行浸泡免疫效果研究。结果表明，pcMCP DNA疫苗能够刺激免疫系统，对非特异性免疫和IgM的表达都具有激活作用。免疫后血液中白细胞含量、白细胞吞噬能力和SOD活力都显著提高，14 d时均达到最大。IgM和Mx基因的mRNA表达研究显示，72 h大量表达，96 h达到最大，分别是对照组的3.05倍和2.02倍。攻毒试验显示，浸泡免疫能够有效保护ISKNV感染的鳜鱼，在第11天，浸泡免疫组的累计死亡率仅为40%，而对照组死亡率都达到了100%，pcMCP浸泡免疫降低了ISKNV感染的鳜鱼死亡率。

关键词：鳜鱼（Siniperca chuatsi）；DNA疫苗；浸泡免疫；传染性脾肾坏死病毒

中图分类号：S942.5 文献标识码：A 文章编号：0439-8114（2017）14-2731-05

DOI：10.14088/j.cnki.issn0439-8114.2017.14.034

Abstract：In this study， ISKNV MCP gene was cloned into eukaryotic expression plasmid pcDNA3.1（+） to construct DNA vaccine，pcMCP，to study the immune effect of DNA vaccine. The results showed that immersion immunity by pcMCP DNA vaccine could stimulate the immune system. After immunization，White blood cell content，leukocyte phagocytosis and SOD were significantly improved，and they reached the maximum at 14th day. The mRNA level of IgM and Mx gene was expressed at 72 h，and reached the maximum at 96 h， and they were upto 3.05 fold and 2.02 fold respectively，compared with control group. Challenge test， immersion immunization could effectively protect the ISKNV infected mandarin fish. at the eleventh day，the total death rate of immersion immunization groupwas only 40%， the control groups were mortality rate reached 100%. So these results showed that immersion immunity of DNA vaccine reduced death of ISKNV infected Mandarin fish.

Key words：mandarin fish（Siniperca chuatsi）； DNA vaccine； immersion immunization； infectious spleen and kidney necrosis virus

病毒性疾病对水产养殖业造成的损失呈上升趋势，且大多缺乏针对性的治疗药物和手段，疫苗防控作为疾病控制方法越来越受到水产养殖业的重视[1，2]。目前，大量使用的注射免疫方式使得水产疫苗在水产养殖业的应用和推广受到了很大的限制。因此，开发使用简单、成本低廉的DNA疫苗和免疫方式對水产养殖业尤为重要。研究表明，基于黏膜系统的疫苗能够提高病原体感染后试验动物的生存能力[3，4]。DNA疫苗不仅能够通过黏膜系统使鱼体产生足够的免疫保护力，同时还能够刺激机体非特异性免疫产生额外的免疫保护力[5-8]。

鳜鱼病毒病对中国的鳜鱼养殖业造成很大危害，其主要病原是传染性脾肾坏死病毒（Infectious spleen and kidney necrosis virus，ISKNV）。……