Huang Zhenyu, Liu Naicheng, Xue Mingyang, Xu Chen, Fan Yuding, Meng Yan, Jiang Nan, Li Yiqun, Liu Wenzhi, He Yang, Zhou Yong
Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, Hubei, China.
Key Laboratory of Sichuan Province for Fishes Conservation and Utilization in the Upper Reaches of the Yangtze River, Neijiang Normal University, Neijiang, Sichuan, China.
Front Immunol. 2025 Jan 29;16:1515684. doi: 10.3389/fimmu.2025.1515684. eCollection 2025.
Immunoglobulin M (IgM) and IgM B cells are key components of the humoral immune system, providing defense against pathogen invasion. While the role of IgM in the systemic and mucosal immune responses of fish to parasites and bacteria has been partially investigated, its function in viral infections remains underexplored. This study successfully developed a largemouth bass () model for ranavirus immersion infection. Our findings revealed that viral infection caused significant pathological changes in the gill and head kidney tissues, along with a marked upregulation of adaptive immune gene expression. Interestingly, fish that survived an initial viral infection exhibited minimal mortality and low viral loads in the gill and head kidney tissues when exposed to a higher viral concentration. Notably, in these fish with secondary infections, there was a significant increase in IgM protein levels in both the blood and gill mucus, as well as a pronounced accumulation of IgM B cells in the gill and head kidney tissues. Additionally, the serum contained high levels of virus-specific IgM, which demonstrated the ability to neutralize the virus. These findings highlight the crucial role of IgM in the immune response to viral infections in largemouth bass and suggest its potential as a target for enhancing viral resistance in aquaculture.
免疫球蛋白M（IgM）和IgM B细胞是体液免疫系统的关键组成部分，为抵御病原体入侵提供防御。虽然IgM在鱼类对寄生虫和细菌的全身及黏膜免疫反应中的作用已得到部分研究，但其在病毒感染中的功能仍未得到充分探索。本研究成功建立了一个针对蛙病毒浸泡感染的大口黑鲈（ ）模型。我们的研究结果表明，病毒感染导致鳃和头肾组织出现显著的病理变化，同时适应性免疫基因表达明显上调。有趣的是，在初次病毒感染中存活下来的鱼，当暴露于更高病毒浓度时，其死亡率极低，鳃和头肾组织中的病毒载量也很低。值得注意的是，在这些继发感染的鱼中，血液和鳃黏液中的IgM蛋白水平显著增加，鳃和头肾组织中IgM B细胞也明显积聚。此外，血清中含有高水平的病毒特异性IgM，证明其具有中和病毒的能力。这些发现突出了IgM在大口黑鲈对病毒感染的免疫反应中的关键作用，并表明其作为增强水产养殖中病毒抗性靶点的潜力。
