文献类型：期刊文献

英文题名：Siglec7 functions as an inhibitory receptor of non-specific cytotoxic cells and can regulate the innate immune responses in a primitive vertebrate (Oreochromis niloticus)

作者：Zhang, Zhiqiang[1,2]; Li, Xing[1]; Huang, Meiling[1]; Huang, Yongxiong[1]; Tan, Xuyan[1]; Dong, Yuhang[1]; Huang, Yu[1,2,3]; Jian, Jichang[1,2,3]

机构：[1] College of Fishery, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, Zhanjiang, China; [2] Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China; [3] Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, Shenzhen, China

年份：2024

卷号：278

外文期刊名：International Journal of Biological Macromolecules

收录：EI(收录号：20243416924128)、Scopus(收录号：2-s2.0-85201697826)

语种：英文

外文关键词：Cell membranes - Cytotoxicity - Histology - Immune system - Macroinvertebrates - Macrophages - Mammals - Pathogens

外文摘要：In mammals, siglec7, an integral component of the siglecs, is principally found on the surface of natural killer (NK) cells, macrophages, and monocytes, where it interacts with various pathogens to perform immunological regulatory activities. Nonetheless, the immune defense and mechanism of siglec7 in early vertebrates remain unknown. In this study, we identified siglec7 from Oreochromis niloticus (OnSiglec7) and revealed its immune functions. Specifically, OnSiglec7 was abundantly expressed in immune-related tissues of healthy tilapia and its transcription level was strongly activated after being challenged with A. hydrophila, S. agalactiae, and Poly: IC. Meanwhile, OnSiglec7 protein was purified and analyzed, which could recognize multiple pathogens through binding and agglutinating activity. Moreover, OnSiglec7-positive cells were mainly distributed in non-specific cytotoxic cells (NCC) of tilapia HKLs and showed cell membrane localization. Furthermore, OnSiglec7 blockage affected multiple innate immune responses (inflammation, apoptosis, and pyroptosis process) by regulating the activation of MAPK, NF-κB, TLR, and JAK-STAT pathways. Finally, OnSiglec7 blockage also greatly enhanced the cytotoxic effect of tilapia NCC. Summarily, this study uncovers immune functions and mechanisms of siglec7 in primitive vertebrates, thereby enhancing our understanding of the systemic evolution and ancient functions of other siglecs within the host's innate immune system (to our knowledge). ? 2024