文献类型：期刊文献

英文题名：NK-lysin from Oreochromis niloticus improves antimicrobial defence against bacterial pathogens

作者：Huang, Yu[1,2,3];Zheng, Qi[1,2,3];Niu, Jinzhong[1,2,3];Tang, Jufen[1,2,3];Wang, Bei[1,2,3];Abarike, Emmanuel Delwin[1,2,3];Lu, Yishan[1,2,3];Cai, Jia[1,2,3];Jian, Jichang[1,2,3]

机构：[1]Guangdong Ocean Univ, Coll Fishery, Zhanjiang 524088, Peoples R China;[2]Guangdong Prov Key Lab Pathogen Biol & Epidemiol, Zhanjiang 524088, Peoples R China;[3]Guangdong Key Lab Control Dis Aquat Econ Anim, Zhanjiang 524088, Peoples R China

年份：2018

卷号：72

起止页码：259

外文期刊名：FISH & SHELLFISH IMMUNOLOGY

收录：SCI-EXPANDED(收录号：WOS:000423644600030)、、Scopus(收录号：2-s2.0-85032983793)、WOS

基金：This work was supported by National Natural Science Foundation of China (Grant no. 31302226, 31572651), Technology Planning Project of Guangdong Province of China (grant no. 2015A020209181) and Excellent Doctoral Dissertation Breeding Project of Guangdong Ocean University (Grant no. 201602).

语种：英文

外文关键词：Oreochromis niloticus; NK-Lysin; Streptococcus agalactiae; Antibacterial activity; Antimicrobial peptide

外文摘要：NK-lysin, an effector of cytotoxic T cells and natural killer cells, is a potent antimicrobial peptide widely distributed in mammals. Homologues of NK-lysin have been discovered in several teleost species, but only several of their natural functions was recorded so far. Here we identified an NK-lysin from Nile tilapia (Oreochromis niloticus), On-NKL, and analysed its expression model and biological effects on pathogen infection. The open reading frame of On-NKL sequence spans 432 bp, codes for 143 amino acids and shares 27%-62% overall sequence identities with NK-lysin of other species. The deduced mature peptide of On-NKL possesses a saposin B domain and six well-conserved cysteine residues that essential for antimicrobial activity by forming three intrachain disulphide bonds. The results of qRT-PCR showed that On-NKL expression was observed in multiple tissues and head kidney leucocytes and nonspecific cytotoxic cells (NCCs) and is most abundant in gills. After bacterial challenge, On-NICL expression significantly varied in different tissues and NCCs. Following bacterial infection, On-NKL-overexpressing fish featured significantly lower pathogen loads in tissues than control fish. On-NKL-overexpressing fish also exhibited 33.3% relative percent survival compare with control groups. Findings suggested that On-NKL could be the potential effector of NCCs and act as immune-related gene that enhances antimicrobial defence.