文献类型：期刊文献

英文题名：LECT2 Protects Nile Tilapia (Oreochromis niloticus) Against Streptococcus agalatiae Infection

作者：Li, Qi[1];Zhang, Zhiqiang[1];Fan, Weiqi[1];Huang, Yongxiong[1];Niu, Jinzhong[1];Luo, Guoling[1];Liu, Xinchao[1];Huang, Yu[1,2,3];Jian, Jichang[1,2,3]

机构：[1]Guangdong Ocean Univ, Coll Fishery,Southern Marine Sci & Engn Guangdong, Key Lab Control Dis Aquat Anim Guangdong Higher E, Guangdong Prov Key Lab Pathogen Biol & Epidemiol, Zhanjiang, Peoples R China;[2]Qingdao Natl Lab Marine Sci & Technol, Lab Marine Biol & Biotechnol, Qingdao, Peoples R China;[3]Guangdong Prov Engn Res Ctr Aquat Anim Hlth Asses, Shenzhen, Peoples R China

年份：2021

卷号：12

外文期刊名：FRONTIERS IN IMMUNOLOGY

收录：SCI-EXPANDED(收录号：WOS:000657440300001)、、WOS

基金：This work was supported by the National Key R&D Program of China (No. 2018YFD0900501), the National Natural Science Foundation of China (No. U20A2065, 32073006, 32002426), the Fund of Southern Marine Science and Engineering Guangdong Laboratory (Zhanjiang) (No. ZJW-2019-06).

语种：英文

外文关键词：LECT2; Nile tilapia; Streptococcus agalactiae; immune response; CLR

外文摘要：Leukocyte cell-derived chemotaxin 2 (LECT2) is a multifunctional cytokine that especially plays an important role in innate immune. However, the roles of LECT2 in the immune response of the economically important fish Nile tilapia (Oreochromis niloticus) against bacterial infection remains unclear. In this study, a lect2 gene from Nile tilapia (On-lect2) was identified, and its roles in the fish's immune response against bacterial infection were determined and characterised. On-lect2 contains an open reading frame of 456 bp that encodes a peptide of 151 amino acids, as well as the conservative peptidase M23 domain. On-LECT2 is 62%-84% identical to other fish species and about 50% identical to mammals. The highest transcriptional level of On-lect2 was detected in the liver, whereas the lowest levels were detected in the other tissues. Moreover, the On-LECT2 protein is located mainly in the brain and head kidney. The transcriptional levels of On-lect2 substantially increased in the head kidney, brain, liver and spleen after Streptococcus agalactiae infection. Knockdown On-lect2 led to higher mortality due to liver necrosis or haemorrhage and splenomegaly. In vitro analysis indicated that the recombinant protein of On-LECT2 improved phagocytic activity of head kidney-derived macrophages. In vivo challenge experiments revealed several functions of On-LECT2 in the immune response of Nile tilapia against bacterial infection, including promotion of inflammation, reduction of tissue damages and improvement of survival rate.