Li Fuyan, Ge Hui, Lin Peng, Wang Yilei, Jiang Yonghua, Zhang Ziping, Chen Yun, Feng Jianjun
State Key Laboratory of Mariculture Breeding, Key Laboratory of Healthy Mariculture for the East China Sea, Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, Fisheries College, Jimei University, Xiamen, Fujian Province, 361021, China.
State Key Laboratory of Mariculture Breeding, Key Laboratory of Healthy Mariculture for the East China Sea, Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, Fisheries College, Jimei University, Xiamen, Fujian Province, 361021, China; Key Laboratory of Cultivation and High-value Utilization of Marine Organisms in Fujian Province, Fisheries Research Institute of Fujian, Xiamen, 361012, China.
Fish Shellfish Immunol. 2025 Oct;165:110440. doi: 10.1016/j.fsi.2025.110440. Epub 2025 May 21.
Vibrio harveyi, a major aquatic pathogen prevalent in tropical and subtropical waters, causes substantial economic losses in global mariculture. This study focused on developing subunit vaccines targeting the outer membrane proteins of a new highly virulent strain of V. harveyi, which are recognized as key protective antigens. We performed whole-genome sequencing of a highly virulent endemic strain, followed by systematic screening and identification of immunogenic OMPs. Two candidate antigens, OmpW and OmpK, were successfully expressed and purified using a prokaryotic expression system. To assess the protective efficacy of the vaccine, pearl gentian grouper (Epinephelus lanceolatus × Epinephelus fuscoguttatus) were immunized via intraperitoneal injection, followed by a challenge with a virulent strain of V. harveyi. Comprehensive genomic characterization of the pathogen indicated the presence of a wide array of virulence-associated genes, from which 17 antigenic proteins were selected as potential candidates for vaccine development. Compared to the GST control group, grouper immunized with recombinant OmpW or OmpK showed significantly higher serum antibody titers (P < 0.05) and substantial upregulation (2.15-48.6 fold) of key immune-related genes (MHCII and IL1β) in head kidney tissues. Notably, vaccinated fish exhibited a 38.7-50 % increase in serum lysozyme activity, confirming the activation of innate immune mechanisms. These findings collectively demonstrate that OmpW and OmpK provide comprehensive immune protection through synergistic enhancement of both adaptive (specific antibody production) and innate (lysozyme-mediated) immune responses. Histopathological examination confirmed the protective effects, showing significantly reduced inflammatory lesions and cellular necrosis in vital organs (head kidney, spleen, and liver) of immunized fish. Our results demonstrate that recombinant OmpW and OmpK proteins induce comprehensive immune protection through synergistic activation of both humoral and cellular immune pathways, establishing a foundation for developing effective V. harveyi subunit vaccines.
哈维氏弧菌是一种主要流行于热带和亚热带水域的水生致病菌，在全球海水养殖中造成了巨大的经济损失。本研究聚焦于开发针对一种新的高毒力哈维氏弧菌菌株外膜蛋白的亚单位疫苗，这些外膜蛋白被认为是关键的保护性抗原。我们对一株高毒力地方菌株进行了全基因组测序，随后对免疫原性外膜蛋白进行了系统筛选和鉴定。使用原核表达系统成功表达并纯化了两种候选抗原OmpW和OmpK。为评估疫苗的保护效果，通过腹腔注射对珍珠龙胆石斑鱼（鞍带石斑鱼×棕点石斑鱼）进行免疫，随后用一株哈维氏弧菌强毒株进行攻毒。对该病原体的全面基因组特征分析表明存在大量与毒力相关的基因，从中选择了17种抗原蛋白作为疫苗开发的潜在候选物。与谷胱甘肽S-转移酶（GST）对照组相比，用重组OmpW或OmpK免疫的石斑鱼血清抗体滴度显著更高（P<0.05），头肾组织中关键免疫相关基因（MHCII和IL1β）大幅上调（2.15 - 48.6倍）。值得注意的是，接种疫苗的鱼血清溶菌酶活性提高了38.7 - 50%，证实了先天免疫机制的激活。这些发现共同表明，OmpW和OmpK通过协同增强适应性（特异性抗体产生）和先天（溶菌酶介导）免疫反应提供全面的免疫保护。组织病理学检查证实了保护作用，显示免疫鱼重要器官（头肾、脾脏和肝脏）的炎症病变和细胞坏死显著减少。我们的结果表明，重组OmpW和OmpK蛋白通过体液和细胞免疫途径的协同激活诱导全面的免疫保护，为开发有效的哈维氏弧菌亚单位疫苗奠定了基础。
