title: Characterization and mucosal responses of interleukin 17 family ligand and receptor genes in channel catfish Ictalurus punctatus.
abstract: Interleukin (IL) 17 family cytokines are important mediators of mucosal immune responses, tightly regulated by signals from the complex milieu of pathogenic and commensal microbes, epithelial cells and innate and adaptive leukocytes found at tissue barriers. In mammals, IL17 ligand expression has been linked not only to protective immunity but also excessive tissue inflammation and damage in the gut and lungs. To better understand the scope and action of the IL17 family in channel catfish Ictalurus punctatus, we identified and characterized seven IL17 ligands and four IL17 receptor (IL17R) homologues from transcriptomic and genomic databases. To gain insight into the mucosal actions of the IL17A/Fs-associated pathway in inflammatory processes, the expression profiles of three IL17A/Fs and their putative receptors IL17RA and IL17RC in mucosal tissues of catfish following experimental challenge with Edwardsiella ictaluri and Flavobacterium columnare were investigated. Bacterial challenge induced higher expression of the catfish IL17A/Fs as early at 4 h post-infection, particularly in gill tissue. In contrast, in the catfish intestine, where IL17 function is best understood in mouse models, IL17A/F expression showed minimal early responses to E. ictaluri infection. Instead, a significant up-regulation of IL17 ligands and receptors was observed in the intestine at 7 d, highlighting species and tissue-specific regulation of the IL17 family.
authors.affiliation: School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, AL 36849, USA; Jiangsu Key Laboratory of Marine Biotechnology, Huaihai Institute of Technology, Lianyungang 222005, China.
authors.forename: Xingqiang
authors.initials: X
authors.lastname: Wang
authors.affiliation: School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, AL 36849, USA.
authors.forename: Chao
authors.initials: C
authors.lastname: Li
authors.affiliation: School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, AL 36849, USA.
authors.forename: Wilawan
authors.initials: W
authors.lastname: Thongda
authors.affiliation: School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, AL 36849, USA.
authors.forename: Yupeng
authors.initials: Y
authors.lastname: Luo
authors.affiliation: United States Department of Agriculture, Stuttgart National Aquaculture Research Center, Stuttgart, AR 72160, USA.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Beck
authors.affiliation: School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, AL 36849, USA. Electronic address: peatmer@auburn.edu.
authors.forename: Eric
authors.initials: E
authors.lastname: Peatman
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D005786:Gene Expression Regulation / Q000502:physiology*; D007059:Ictaluridae; D020381:Interleukin-17 / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D053722:Receptors, Interleukin-17 / Q000235:genetics / Q000378:metabolism*
chemical_list: D020381:Interleukin-17; D053722:Receptors, Interleukin-17
keywords: Catfish; Interleukin 17; Interleukin 17 receptor; Mucosal immunity