title: The effect of adjuvant and microbial challenge on the expression of antimicrobial polypeptides in channel catfish (Ictalurus punctatus).
abstract: While antimicrobial polypeptides (AMPPs) are increasingly recognized as one of the most important components of innate immunity, there is very little information in vertebrates that documents their upregulation to levels that are microbicidal in vivo. Here we demonstrate that intraperitoneal injection of either Freund's complete adjuvant (FCA) or live Tetrahymena pyriformis (a parasitic ciliate) upregulated AMPP expression in channel catfish skin. FCA induced significant upregulation of total antibacterial activity, anti-Edwardsiella ictaluri activity (the fraction of antibacterial activity active against E. ictaluri), and HLP-1 (the major AMPP in channel catfish skin). Tetrahymena induced a similar upregulation, except that HLP-1 was not significantly induced and the response appeared to be more transient than FCA immunostimulation. AMPP levels were increased up to five-fold higher than resting levels and levels expressed were well within concentrations known to be inhibitory to many important pathogens in vitro. These results provide encouragement that AMPP upregulation may be a promising tool in aquaculture for enhancing the resistance of fish to disease.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA.
authors.forename: Eman
authors.initials: E
authors.lastname: Zahran
authors.forename: Jung-Kil
authors.initials: JK
authors.lastname: Seo
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Noga
mesh_terms: D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000235:genetics / Q000276:immunology*; D020610:Edwardsiella ictaluri / Q000276:immunology; D004756:Enterobacteriaceae Infections / Q000276:immunology / Q000662:veterinary; D005393:Fish Diseases / Q000276:immunology*; D005620:Freund's Adjuvant / Q000276:immunology*; D005786:Gene Expression Regulation; D007059:Ictaluridae / Q000235:genetics* / Q000276:immunology*; D007113:Immunity, Innate / Q000276:immunology; D013769:Tetrahymena pyriformis / Q000276:immunology*; D015854:Up-Regulation
chemical_list: D023181:Antimicrobial Cationic Peptides; D005620:Freund's Adjuvant