title: Expression of the Bovine NK-Lysin Gene Family and Activity against Respiratory Pathogens.
abstract: Unlike the genomes of many mammals that have a single NK-lysin gene, the cattle genome contains a family of four genes, one of which is expressed preferentially in the lung. In this study, we compared the expression of the four bovine NK-lysin genes in healthy animals to animals challenged with pathogens known to be associated with bovine respiratory disease (BRD) using transcriptome sequencing (RNA-seq). The expression of several NK-lysins, especially NK2C, was elevated in challenged relative to control animals. The effects of synthetic peptides corresponding to functional region helices 2 and 3 of each gene product were tested on both model membranes and bio-membranes. Circular dichroism spectroscopy indicated that these peptides adopted a more helical secondary structure upon binding to an anionic model membrane and liposome leakage assays suggested that these peptides disrupt membranes. Bacterial killing assays further confirmed the antimicrobial effects of these peptides on BRD-associated bacteria, including both Pasteurella multocida and Mannhemia haemolytica and an ultrastructural examination of NK-lysin-treated P. multocida cells by transmission electron microscopy revealed the lysis of target membranes. These studies demonstrate that the expanded bovine NK-lysin gene family is potentially important in host defense against pathogens involved in bovine respiratory disease.
authors.affiliation: Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, United States of America.
authors.forename: Junfeng
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, United States of America.
authors.forename: Chingyuan
authors.initials: C
authors.lastname: Yang
authors.affiliation: Embrapa Southeast Livestock, São Carlos, Brazil.|Division of Animal Sciences, University of Missouri, Columbia, United States of America.
authors.forename: Polyana C
authors.initials: PC
authors.lastname: Tizioto
authors.affiliation: Department of Physiology and Pharmacology, College of Veterinary Medicine, Texas A&M University, College Station, United States of America.
authors.forename: Huan
authors.initials: H
authors.lastname: Huang
authors.affiliation: Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, United States of America.
authors.forename: Mi O K
authors.initials: MO
authors.lastname: Lee
authors.affiliation: Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, United States of America.
authors.forename: Harold R
authors.initials: HR
authors.lastname: Payne
authors.affiliation: Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, United States of America.
authors.forename: Sara D
authors.initials: SD
authors.lastname: Lawhon
authors.affiliation: Department of Physiology and Pharmacology, College of Veterinary Medicine, Texas A&M University, College Station, United States of America.
authors.forename: Friedhelm
authors.initials: F
authors.lastname: Schroeder
authors.affiliation: Division of Animal Sciences, University of Missouri, Columbia, United States of America.
authors.forename: Jeremy F
authors.initials: JF
authors.lastname: Taylor
authors.affiliation: Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, United States of America.
authors.forename: James E
authors.initials: JE
authors.lastname: Womack
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000494:pharmacology*; D048090:Bovine Respiratory Disease Complex / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology / Q000382:microbiology* / Q000517:prevention & control; D002462:Cell Membrane / Q000378:metabolism*; D002942:Circular Dichroism; D008168:Lung / Q000201:enzymology; D016978:Mannheimia haemolytica / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D046529:Microscopy, Electron, Transmission; D016979:Pasteurella multocida / Q000187:drug effects*; D011510:Proteolipids / Q000235:genetics / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; C093238:NK-lysin; D011510:Proteolipids