College of Life Science, Henan Normal University, Xinxiang, Henan, 453007, China.
Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, Nanjing, 210046, China.
Fish Shellfish Immunol. 2019 Sep;92:583-589. doi: 10.1016/j.fsi.2019.06.042. Epub 2019 Jun 24.
Toll-like receptors (TLRs) play an important role in the activation of innate immune response in animals. In this study, we identified a TLR from the oriental river prawn, Macrobrachium nipponense (MnToll1) and investigated its functions in immunity. The MnToll1 protein shares similar structural characteristics with other known Toll family proteins. MnToll1 transcripts are broadly distributed in all of the examined tissues, and its expression level was significantly up-regulated by bacterial challenge. RNAi-mediated knockdown of MnToll1 significantly impaired the survivability of Vibrio-challenged prawns. RNAi experiments also revealed that the expression of several antimicrobial peptide genes were regulated by MnToll1. Moreover, we found the extracellular region of MnToll1 could directly bind to bacteria and bacterial glycoconjugates. These findings suggest that MnToll1 function as a pattern recognition receptor to recognize invading pathogen and initiate downstream gene expression, to participate in antibacterial defense of M. nipponense.
Toll-like 受体（TLRs）在动物固有免疫反应的激活中起着重要作用。在这项研究中，我们从日本沼虾（Macrobrachium nipponense）中鉴定出一种 Toll 受体（MnToll1），并研究了其在免疫中的功能。MnToll1 蛋白与其他已知的 Toll 家族蛋白具有相似的结构特征。MnToll1 转录本广泛分布于所有检测到的组织中，其表达水平在细菌刺激下显著上调。MnToll1 的 RNAi 介导敲低显著降低了对虾对弧菌的存活率。RNAi 实验还表明，几种抗菌肽基因的表达受 MnToll1 调控。此外，我们发现 MnToll1 的细胞外区域可以直接结合细菌和细菌糖缀合物。这些发现表明，MnToll1 作为一种模式识别受体，识别入侵病原体并启动下游基因表达，参与日本沼虾的抗菌防御。
