Li Shouhu, Li Xincang, Yuan Rui, Chen Xiaoxue, Chen Shouxu, Qiu Yu, Yang Qingfeng, Wang Meng, Shi Jiangao, Zhang Shuo
Key Laboratory of Oceanic and Polar Fisheries, Ministry of Agriculture and Rural Affairs; East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, 300 Jungong Road, Shanghai, 200090, China; College of Marine Science, Shanghai Ocean University, 999 Huan Road, Shanghai, 200090, China.
Key Laboratory of Oceanic and Polar Fisheries, Ministry of Agriculture and Rural Affairs; East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, 300 Jungong Road, Shanghai, 200090, China.
Fish Shellfish Immunol. 2023 Jan;132:108457. doi: 10.1016/j.fsi.2022.108457. Epub 2022 Nov 29.
Infectious hematopoietic necrosis virus (IHNV) and infectious pancreatic necrosis virus (IPNV) are typical pathogens of rainbow trout Oncorhynchus mykiss, and the concurrent infection of the two viruses is very common among modern trout hatcheries, which has caused huge economic losses to the rainbow trout farming industry. To prevent and control the spread of IHNV and IPNV in juvenile trout simultaneously, in this study a bivalent recombinant adenovirus vaccine with IHNV Glycoprotein (G) and IPNV VP2 genes was developed. After immunizing juvenile trout with this bivalent vaccine via the immersion route, the expression levels of IHNV G and IPNV VP2 and the representative immune genes in vaccinated and control rainbow trout were tested to evaluate the correlation of immune responses with the expression of viral genes. The neutralizing antibody level induced by this bivalent vaccine as well as the protection efficacy of the vaccine against IHNV and IPNV was also evaluated. The results showed that IHNV G and IPNV VP2 were successfully expressed in juvenile trout, and all the innate and adaptive immune genes were up-regulated. This indicated that the level of the innate and adaptive immune responses were significantly increased, which might be induced by the high expression of the two viral proteins. Compared with the controls, high levels of neutralizing antibodies against IHNV and IPNV were induced in the vaccinated trout. Besides, the bivalent recombinant adenovirus vaccine showed high protection rate against IHNV, with the relative percent survival (RPS) of 81.25%, as well as against IPNV, with the RPS of 78.95%. Taken together, our findings clearly demonstrated that replication-defective adenovirus can be developed as a qualified vector for fish vaccines and IHNV G and IPNV VP2 were two suitable antigenic genes that could induce effective immune protection against these two pathogens. This study provided new insights into developing bivalent vectored vaccines and controlling the spread of IHNV and IPNV simultaneously in juvenile trout.
传染性造血器官坏死病毒（IHNV）和传染性胰腺坏死病毒（IPNV）是虹鳟Oncorhynchus mykiss的典型病原体，这两种病毒的混合感染在现代鳟鱼孵化场中非常普遍，给虹鳟养殖业造成了巨大经济损失。为了同时预防和控制IHNV和IPNV在幼鱼中的传播，本研究开发了一种携带IHNV糖蛋白（G）和IPNV VP2基因的二价重组腺病毒疫苗。通过浸泡途径用该二价疫苗免疫幼鱼后，检测了免疫组和对照组虹鳟中IHNV G、IPNV VP2及代表性免疫基因的表达水平，以评估免疫反应与病毒基因表达的相关性。同时还评估了该二价疫苗诱导的中和抗体水平以及疫苗对IHNV和IPNV的保护效果。结果表明，IHNV G和IPNV VP2在幼鱼中成功表达，所有先天免疫和适应性免疫基因均上调。这表明先天免疫和适应性免疫反应水平显著提高，可能是由这两种病毒蛋白的高表达诱导的。与对照组相比，免疫后的鳟鱼诱导产生了高水平的抗IHNV和IPNV的中和抗体。此外，二价重组腺病毒疫苗对IHNV显示出高保护率，相对存活率（RPS）为81.25%，对IPNV的RPS为78.95%。综上所述，我们的研究结果清楚地表明，复制缺陷型腺病毒可被开发为合格的鱼类疫苗载体，IHNV G和IPNV VP2是两种合适的抗原基因，可诱导针对这两种病原体的有效免疫保护。本研究为开发二价载体疫苗以及同时控制IHNV和IPNV在幼鱼中的传播提供了新的见解。
