title: NKLP27: a teleost NK-lysin peptide that modulates immune response, induces degradation of bacterial DNA, and inhibits bacterial and viral infection.
abstract: NK-lysin is an antimicrobial protein produced by cytotoxic T lymphocytes and natural killer cells. In this study, we examined the biological property of a peptide, NKLP27, derived from tongue sole (Cynoglossus semilaevis) NK-lysin. NKLP27 is composed of 27 amino acids and shares little sequence identity with known NK-lysin peptides. NKLP27 possesses bactericidal activity against both Gram-negative and Gram-positive bacteria including common aquaculture pathogens. The bactericidal activity of NKLP27 was dependent on the C-terminal five residues, deletion of which dramatically reduced the activity of NKLP27. During its interaction with the target bacterial cells, NKLP27 destroyed cell membrane integrity, penetrated into the cytoplasm, and induced degradation of genomic DNA. In vivo study showed that administration of tongue sole with NKLP27 before bacterial and viral infection significantly reduced pathogen dissemination and replication in tissues. Further study revealed that fish administered with NKLP27 exhibited significantly upregulated expression of the immune genes including those that are known to be involved in antibacterial and antiviral defense. These results indicate that NKLP27 is a novel antimicrobial against bacterial and viral pathogens, and that the observed effect of NKLP27 on bacterial DNA and host gene expression adds new insights to the action mechanism of fish antimicrobial peptides.
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China; College of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China; Graduate University of the Chinese Academy of Sciences, Beijing, China.
authors.forename: Mo-fei
authors.initials: MF
authors.lastname: Li
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China; Collaborative Innovation Center of Deep Sea Biology, Zhejiang University, Hangzhou, China.
authors.forename: Li
authors.initials: L
authors.lastname: Sun
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D001424:Bacterial Infections / Q000235:genetics / Q000276:immunology / Q000662:veterinary; D004269:DNA, Bacterial / Q000378:metabolism; D005393:Fish Diseases / Q000276:immunology / Q000382:microbiology / Q000821:virology; D029941:Fish Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D005412:Flatfishes / Q000235:genetics / Q000276:immunology*; D015870:Gene Expression; D054884:Host-Pathogen Interactions / Q000235:genetics / Q000276:immunology; D008969:Molecular Sequence Data; D011510:Proteolipids / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D011552:Pseudomonas Infections / Q000235:genetics / Q000276:immunology / Q000662:veterinary; D011551:Pseudomonas fluorescens; D017386:Sequence Homology, Amino Acid; D013290:Streptococcal Infections / Q000235:genetics / Q000276:immunology / Q000662:veterinary; D014733:Vibrio / Q000378:metabolism / Q000472:pathogenicity; D014735:Vibrio Infections / Q000235:genetics / Q000276:immunology / Q000662:veterinary; D014777:Virus Diseases / Q000235:genetics / Q000276:immunology / Q000662:veterinary
chemical_list: D023181:Antimicrobial Cationic Peptides; D004269:DNA, Bacterial; D029941:Fish Proteins; C093238:NK-lysin; D011510:Proteolipids