Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, China.
Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
Front Immunol. 2020 Nov 16;11:583740. doi: 10.3389/fimmu.2020.583740. eCollection 2020.
The olfactory organs (OOs) of vertebrates play important roles in their extraordinary chemosensory capacity, a process during which they are continuously exposed to environmental pathogens. Nasopharynx-associated lymphoid tissue (NALT) contains B cells and immunoglobulins (Igs), which function as the first defense line against antigens in mammals and also exist in teleosts. However, the immune responses of teleost NALT B cells and Igs during bacterial infection remain largely uncharacterized. In this study, rainbow trout were infected with continuous immersion, after which the adaptive immune responses within NALT were evaluated. could invade trout nasal mucosa and cause histopathological changes in trout OO. Moreover, the accumulation of IgT B cells in trout nasal mucosa was induced by bacterial challenge, which was accompanied by strong bacteria-specific IgT responses in the nasal mucus. Importantly, our study is the first to report local nasal-specific immune responses in teleosts during bacterial challenge by characterizing the local proliferation of IgT B cells and generation of bacteria-specific IgT in trout OOs after infection. In addition to the strong IgT and IgT B cells responses in OO, bacteria-specific IgT and IgM were also detected in serum following bacterial challenge. Taken together, our findings suggest that IgT functions as an important mucosal Ig in teleost NALT and mediates local adaptive immunity during bacterial infection, which is similar to their protective role during parasitic infection.
脊椎动物的嗅觉器官 (OO) 在其非凡的化学感觉能力中发挥着重要作用，在这个过程中，它们会不断接触到环境病原体。鼻相关淋巴组织 (NALT) 含有 B 细胞和免疫球蛋白 (Igs)，它们作为哺乳动物对抗抗原的第一道防线发挥作用，也存在于硬骨鱼中。然而，硬骨鱼 NALT B 细胞和 Igs 的免疫反应在细菌感染期间仍然在很大程度上未被描述。在这项研究中，虹鳟鱼通过连续浸泡感染，然后评估 NALT 内的适应性免疫反应。 可以侵入鲑鱼鼻黏膜并引起鲑鱼 OO 的组织病理学变化。此外，细菌挑战诱导了 IgT B 细胞在鲑鱼鼻黏膜中的积累，这伴随着鼻黏液中强烈的细菌特异性 IgT 反应。重要的是，我们的研究首次通过表征感染后鲑鱼 OO 中 IgT B 细胞的局部增殖和细菌特异性 IgT 的产生，来描述硬骨鱼在细菌挑战期间局部鼻特异性免疫反应。除了 OO 中强烈的 IgT 和 IgT B 细胞反应外，在细菌挑战后还在血清中检测到了细菌特异性 IgT 和 IgM。综上所述，我们的研究结果表明，IgT 在硬骨鱼 NALT 中作为一种重要的黏膜 Ig 发挥作用，并在细菌感染期间介导局部适应性免疫，这与它们在寄生虫感染期间的保护作用相似。
