Fish Immunology and Pathology Laboratory, Animal Health Research Center (CISA-INIA), Valdeolmos, Madrid, Spain.
Sci Rep. 2020 Oct 8;10(1):16810. doi: 10.1038/s41598-020-73999-w.
As B cells are singularly equipped with a B cell receptor (BCR) and a range of innate receptors, they are able to integrate both antigen-specific and innate signals, with the latter being essential to reach an adequate level of activation. Whether teleost B cells sense pathogens through innate mechanisms has not yet been explored, despite the fact that fish B cells display a wider array of innate receptors than many mammalian B cell subsets. Hence, in the current study, we have investigated the effects of inactivated Aeromonas salmonicida, a Gram negative rainbow trout pathogen, on trout splenic IgM B cells in vitro in the presence or absence of different inhibitors of Toll-like receptor (TLR) signalling, to establish to what degree innate signals are contributing to the activation of B cells in teleosts. Our results demonstrate that most of the effects that A. salmonicida exerts on trout IgM B cells are significantly blocked in the presence of inhibitors of MyD88 and TRIF, important nodes in TLR signal pathways. Thus, the data presented demonstrates that, also in teleost, TLR signalling is essential for the activation of IgM B cells. These results will be useful for the future optimization of novel vaccines and adjuvants.
由于 B 细胞具有独特的 B 细胞受体 (BCR) 和一系列先天受体，因此它们能够整合抗原特异性和先天信号，而后者对于达到足够的激活水平至关重要。尽管鱼类 B 细胞比许多哺乳动物 B 细胞亚群具有更多的先天受体，但尚未探索过硬骨鱼 B 细胞是否通过先天机制感知病原体。因此，在本研究中，我们在存在或不存在不同 Toll 样受体 (TLR) 信号转导抑制剂的情况下，研究了灭活的鲑鱼气单胞菌（革兰氏阴性虹鳟鱼病原体）对体外虹鳟脾脏 IgM B 细胞的影响，以确定先天信号在多大程度上有助于硬骨鱼 B 细胞的激活。我们的结果表明，在存在 MyD88 和 TRIF 抑制剂的情况下，鲑鱼气单胞菌对虹鳟 IgM B 细胞的大多数作用均受到显著抑制，MyD88 和 TRIF 是 TLR 信号通路中的重要节点。因此，所呈现的数据表明，在硬骨鱼中，TLR 信号对于 IgM B 细胞的激活也是必不可少的。这些结果将有助于未来对新型疫苗和佐剂的优化。
