Jalali Seyed Amir Hossein, Sepehre Nia Saeed, Beyraghdar Kashkooli Omid, Soleimanin-Zad Sabihe
Department of Natural Resources, Isfahan University of Technology, Isfahan, 84156-83111, Iran; Research Institute for Biotechnology and Bioengineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran.
Department of Natural Resources, Isfahan University of Technology, Isfahan, 84156-83111, Iran.
Fish Shellfish Immunol. 2025 Mar;158:110127. doi: 10.1016/j.fsi.2025.110127. Epub 2025 Jan 17.
Infectious hematopoietic necrosis virus (IHNV) is a serious pathogen in the salmonid aquaculture industry and leads to economic losses in the world. This study aimed to develop a new oral DNA vaccine designed to protect rainbow trout against infection by IHNV. Fish were administered via the oral route by the attenuated Salmonella enterica serovar Typhimurium as a carrier of pcDNA3.1-IHNG (glycoprotein (G)) plasmid for 7 days and finally, fish were challenged by 10 pfu ml IHNV. The results revealed that the antigen gene was identified in different tissues of rainbow trout at 15-, 30-, and 45 days post-vaccination (dpv). Also, the recombinant vaccine elicited both an innate and specific immune response, resulting in a significant upregulation of the expression levels of ifn-1, mx-1, vig-1, igm, and igt. In addition, serum levels of neutralizing antibodies were observed to be elevated in the vaccinated fish, in contrast to the unvaccinated fish, following 30 dpv. Compared to trout that received empty S. Typhimurium, notable differences in cumulative percentage mortality were evident among the vaccinated fish. The relative percent survival (RPS) was recorded at 58.2 % for the group that received oral vaccine, while the group that received empty S. Typhimurium exhibited an RPS of 18.2 %. Therefore, our results showed that this bacterial vector can be a candidate carrier for pcDNA3.1-IHNG plasmid that may be employed to confer protection to rainbow trout against IHNV.
传染性造血器官坏死病毒（IHNV）是鲑科水产养殖业中的一种严重病原体，在全球范围内造成经济损失。本研究旨在开发一种新型口服DNA疫苗，以保护虹鳟鱼免受IHNV感染。通过口服途径给鱼施用减毒的肠炎沙门氏菌血清型鼠伤寒沙门氏菌作为pcDNA3.1-IHNG（糖蛋白（G））质粒的载体，持续7天，最后用10 pfu/ml的IHNV对鱼进行攻毒。结果显示，在接种疫苗后15天、30天和45天，在虹鳟鱼的不同组织中鉴定出了抗原基因。此外，重组疫苗引发了先天性和特异性免疫反应，导致ifn-1、mx-1、vig-1、igm和igt的表达水平显著上调。另外，与未接种疫苗的鱼相比，在接种疫苗的鱼中观察到中和抗体的血清水平在接种后30天升高。与接受空的鼠伤寒沙门氏菌的鳟鱼相比，接种疫苗的鱼在累积死亡率百分比上有明显差异。接受口服疫苗的组的相对存活率（RPS）记录为58.2%，而接受空的鼠伤寒沙门氏菌的组的RPS为18.2%。因此，我们的结果表明，这种细菌载体可以作为pcDNA3.1-IHNG质粒的候选载体，可用于保护虹鳟鱼免受IHNV感染。
