College of Fisheries and Life Science, Dalian Ocean University, Dalian, 116023, China.
Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.
Fish Shellfish Immunol. 2024 Feb;145:109326. doi: 10.1016/j.fsi.2023.109326. Epub 2023 Dec 21.
Immunoglobulin M (IgM) specifically recognizes various antigens and can activate complement, mediate cytotoxicity, opsonize and agglutinate pathogens to induce phagocytosis, all of which play an important role in immunity. However, the IgM response of common carp (Cyprinus carpio) in the intestinal mucosa after viral infection has not been thoroughly. Therefore, we successfully produced an anti-carp IgM monoclonal antibody and developed a model of viral infection to study the kinetics of immune responses after viral infection. Our results showed that the expression of IL1-β and Igs were dramatically increased, implying that common carp exhibited a significant innate and adaptive immune response to viral infection. Furthermore, we found that the IgM responses varied between the two infection strategies. At 14 days post-infection (DPI), a significant population of IgM B cells were observed in the gut, accompanied by a sharp rise in IgM levels. The immune response to secondary infection started at 7 DPI, suggesting that the IgM response is faster in the gut after re-infection. Importantly, we also explored the variability of different gut compartments to viral infection, and result revealed a stronger immune response in the hindgut than in the foregut and midgut. Overall, our findings indicate that IgM plays an important role in the intestinal immune response following primary and secondary viral infection, in which the hindgut plays a major immune function.
免疫球蛋白 M（IgM）特异性识别各种抗原，并能激活补体、介导细胞毒性、调理和凝集病原体以诱导吞噬作用，所有这些在免疫中都起着重要作用。然而，关于病毒感染后鲤鱼肠道黏膜中的 IgM 反应尚未得到彻底研究。因此，我们成功地生产了抗鲤鱼 IgM 单克隆抗体，并建立了病毒感染模型，以研究病毒感染后免疫反应的动力学。我们的结果表明，IL1-β 和 Igs 的表达显著增加，这表明鲤鱼对病毒感染表现出显著的先天和适应性免疫反应。此外，我们发现两种感染策略之间的 IgM 反应存在差异。在感染后 14 天（DPI），观察到肠道中存在大量 IgM B 细胞，同时 IgM 水平急剧上升。二次感染的免疫反应在 7 DPI 时开始，这表明再次感染后肠道中的 IgM 反应更快。重要的是，我们还探索了不同肠道区域对病毒感染的变异性，结果表明后肠比前肠和中肠具有更强的免疫反应。总的来说，我们的研究结果表明，IgM 在原发性和继发性病毒感染后的肠道免疫反应中起着重要作用，其中后肠发挥着主要的免疫功能。
