College of Veterinary Medicine, College of Animal Science and Technology, Jilin Provincial Key Laboratory of Animal Microecology and Healthy Breeding, Jilin Provincial Engineering Research Center of Animal Probiotics, Key Laboratory of Animal Production and Product Quality Safety of Ministry of Education, Jilin Agricultural University, Changchun, China.
College of Veterinary Medicine, College of Animal Science and Technology, Jilin Provincial Key Laboratory of Animal Microecology and Healthy Breeding, Jilin Provincial Engineering Research Center of Animal Probiotics, Key Laboratory of Animal Production and Product Quality Safety of Ministry of Education, Jilin Agricultural University, Changchun, China.
Fish Shellfish Immunol. 2024 Dec;155:109986. doi: 10.1016/j.fsi.2024.109986. Epub 2024 Oct 24.
Largemouth bass virus (LMBV) is an infectious pathogen that causes high mortality rates in largemouth bass, and outbreaks of this virus can significantly harm the aquaculture industry. Currently, no vaccine has been developed that can effectively prevent the transmission of LMBV. In this study, we constructed a recombinant Lactobacillus plantarum (L. plantarum) strain capable of expressing the MCP gene of LMBV and displaying this protein on its surface; then, we evaluated the immunoprotective effect of this recombinant bacterium on largemouth bass. Western blotting, immunofluorescence, and flow cytometry confirmed that MCP was successfully expressed and anchored on the surfaces of NC8 cells. Immunization of largemouth bass with NC8-pSIP409-pgsA'-MCP via the oral feeding route induced CD4, CD8, IL-1β, and IL-6 gene expression. In addition, NC8-pSIP409-pgsA'-MCP at different CFUs increased the survival of largemouth bass after LMBV infection; in particular, NC8-pSIP409-pgsA'-MCP (10 CFU) resulted in approximately 30 % survival. NC8-pSIP409-pgsA'-MCP immunization alleviated the pathological changes in the liver and spleen, exerting a more advantageous protective effect. These data suggest that the recombinant L. plantarum strain NC8-pSIP409-pgsA'-MCP can increase the resistance of largemouth bass to LMBV infection and that this strain is a promising candidate oral vaccine for the prevention of LMBV infection.
大口黑鲈病毒（LMBV）是一种传染性病原体，可导致大口黑鲈死亡率升高，该病毒的爆发会对水产养殖业造成严重危害。目前，尚未开发出能够有效预防 LMBV 传播的疫苗。在这项研究中，我们构建了一种能够表达 LMBV 的 MCP 基因并在其表面展示该蛋白的重组植物乳杆菌（L. plantarum）菌株，然后评估了该重组菌对大口黑鲈的免疫保护效果。Western blot、免疫荧光和流式细胞术证实 MCP 成功表达并锚定在 NC8 细胞表面。通过口服途径用 NC8-pSIP409-pgsA'-MCP 对大口黑鲈进行免疫接种可诱导 CD4、CD8、IL-1β 和 IL-6 基因表达。此外，不同 CFU 的 NC8-pSIP409-pgsA'-MCP 增加了大口黑鲈在 LMBV 感染后的存活率；特别是，NC8-pSIP409-pgsA'-MCP（10 CFU）可导致约 30%的存活率。NC8-pSIP409-pgsA'-MCP 免疫接种可减轻肝脏和脾脏的病理变化，发挥更有利的保护作用。这些数据表明，重组 L. plantarum 菌株 NC8-pSIP409-pgsA'-MCP 可以提高大口黑鲈对 LMBV 感染的抵抗力，该菌株是预防 LMBV 感染的一种有前途的口服疫苗候选物。
