title: Tissue expression and antibacterial activity of host defense peptides in chicken.
abstract: BACKGROUND
  Host defence peptides are a diverse group of small, cationic peptides and are important elements of the first line of defense against pathogens in animals. Expression and functional analysis of host defense peptides has been evaluated in chicken but there are no direct, comprehensive comparisons with all gene family and individual genes.
  
  
  RESULTS
  We examined the expression patterns of all known cathelicidins, β-defensins and NK-lysin in multiple selected tissues from chickens. CATH1 through 3 were predominantly expressed in the bone marrow, whereas CATHB1 was predominant in bursa of Fabricius. The tissue specific pattern of β-defensins generally fell into two groups. β-defensin1-7 expression was predominantly in bone marrow, whereas β-defensin8-10 and β-defensin13 were highly expressed in liver. NK-lysin expression was highest in spleen. We synthesized peptide products of these gene families and analysed their antibacterial efficacy. Most of the host defense peptides showed antibacterial activity against E.coli with dose-dependent efficacy. β-defensin4 and CATH3 displayed the strongest antibacterial activity among all tested chicken HDPs. Microscopic analyses revealed the killing of bacterium by disrupting membranes with peptide treatment.
  
  
  CONCLUSIONS
  These results demonstrate dose-dependent antimicrobial effects of chicken HDPs mediated by membrane damage and demonstrate the differential tissue expression pattern of bioactive HDPs in chicken and the relative antimicrobial potency of the peptides they encode.
authors.affiliation: WCU Biomodulation Major, Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea.|Department of Veterinary Pathobiology, Texas A & M University, College Station, TX, USA.
authors.forename: Mi Ok
authors.initials: MO
authors.lastname: Lee
authors.affiliation: WCU Biomodulation Major, Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea.|College of Pharmacy, Dankook University, Cheonan, Korea.
authors.forename: Hyun-Jun
authors.initials: HJ
authors.lastname: Jang
authors.affiliation: WCU Biomodulation Major, Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea.
authors.forename: Deivendran
authors.initials: D
authors.lastname: Rengaraj
authors.affiliation: WCU Biomodulation Major, Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea.
authors.forename: Seo-Yeong
authors.initials: SY
authors.lastname: Yang
authors.affiliation: WCU Biomodulation Major, Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea.
authors.forename: Jae Yong
authors.initials: JY
authors.lastname: Han
authors.affiliation: Department of Animal Science, Iowa State University, Ames, IA, USA.
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Lamont
authors.affiliation: WCU Biomodulation Major, Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea. jwomack@cvm.tamu.edu.|Department of Veterinary Pathobiology, Texas A & M University, College Station, TX, USA. jwomack@cvm.tamu.edu.
authors.forename: James E
authors.initials: JE
authors.lastname: Womack
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D023181:Antimicrobial Cationic Peptides / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology*; D054804:Cathelicidins / Q000235:genetics / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects; D002645:Chickens; D004926:Escherichia coli / Q000187:drug effects*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D011510:Proteolipids / Q000235:genetics / Q000378:metabolism; D014018:Tissue Distribution; D023083:beta-Defensins / Q000235:genetics / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D054804:Cathelicidins; C093238:NK-lysin; D011510:Proteolipids; D023083:beta-Defensins
keywords: Antimicrobial; Chicken; Host defence peptides (HDPs)