文献类型： 外文期刊

作者： Hao, Dong-fang ¹ ; Wang, Guang-hua ¹ ; Li, Ning-qiu ³ ; Liu, Hong-mei ¹ ; Wang, Chang-biao ¹ ; Liu, Wen-qing ¹ ; Yan, Xue ¹ ; Zhang, Min ¹ ;

作者机构： 1.Qingdao Agr Univ, Sch Marine Sci & Engn, Qingdao 266109, Shandong, Peoples R China

2.Pilot Natl Lab Marine Sci & Technol, Lab Marine Biol & Biotechnol, Qingdao 266109, Shandong, Peoples R China

3.Chinese Acad Fishery Sci, Pearl River Fisheries Res Inst, Key Lab Fishery Drug Dev, Key Lab Aquat Anim Immune Technol,Minist Agr, Guangzhou 510380, Guangdong, Peoples R China

关键词： NK-Lysin; SsNKLP27; Antibacterial; Antiviral; Immunoregulatory

期刊名称：FISH & SHELLFISH IMMUNOLOGY （ 影响因子：4.622； 五年影响因子：4.799 ）

ISSN： 1050-4648

年卷期： 2022 年 123 卷

页码：

收录情况： SCI

摘要： Natural killer lysin (NK-lysin) is a small molecule antimicrobial peptide secreted by natural killer cells and T lymphocytes. In this study, we characterized a cDNA sequence encoding an NK-lysin homologue (SsNKL1) from black rockfish, Sebastes schlegelii. The open reading frame (ORF) of SsNKL1 encodes a putative protein of 149 amino acids and shares 44%-87% overall sequence identities with other teleost NK-lysins. SsNKL1 possesses conserved NK-lysin family features, including a signal sequence and a surfactant-associated protein B (SapB) domain, sequence analysis revealed that SsNKL1 is most closely related to false kelpfish (Sebastiscus marmoratus) NK-lysin (with 87% sequence identity). SsNKL1 transcripts were detected in all the tested tissues, with the highest level in the kidney, followed by the spleen and gills. Upon Listonella anguillarum infection, the mRNA expression of SsNKL1 in the black rockfish was significantly up-regulated in the liver and kidney. The derived peptide SsNKLP27 from SsNKL1 was synthesized, and its biological function was studied. SsNKLP27 showed direct antibacterial activity against Gram-negative and Gram-positive bacteria, including Staphylococcus aureus, Bacillus subtilis, L. anguillarum, Vibrio parahaemolyticus, Vibrio alginolyticus and Vibrio vulnificus. SsNKLP27 treatment facilitated the bactericidal process of erythromycin by enhancing the permeability of the outer membrane. In the process of interaction with the target bacterial cells, SsNKLP27 changed the permeability and retained the morphological integrity of the cell membrane, then penetrated into the cytoplasm, and induced the degradation of genomic DNA and total RNA. In vivo studies showed that administration of SsNKLP27 before bacterial and viral infection significantly reduced the transmission and replication of pathogens in tissues. In vitro analysis showed that SsNKLP27 could enhance the respiratory burst ability and regulate the expression of some immune-related genes of macrophages. In summary, these results provided new insights into the function of NKlysins in teleost fish and support that SsNKLP27 is a new broad-spectrum antimicrobial peptide that has a potential application prospect in aquaculture against pathogenic infection.