title: A synthetic peptide derived from the D1 domain of flagellin induced the expression of proinflammatory cytokines in fish macrophages.
abstract: Flagellin is the main protein component of flagellum in Gram negative and positive bacteria, and it is also the ligand that activates the Toll-like receptor 5 (TLR5) in fish and mammals. In higher vertebrates, flagellin induces the activation of the membrane-bound TLR5 (TLR5M), which promotes the expression of proinflammatory cytokines and chemokines, and other immunological functions. We have previously reported that recombinant flagellin from Vibrio anguillarum and its ND1 domain are able to upregulate the expression of genes encoding major the proinflammatory mediators in gilthead seabream and rainbow trout macrophages. Considering the key role of D1 domain of flagellin for binding to TLR5M and its immunostimulatory activity, we designed and chemically synthesized a peptide derived of this region. The effects of the synthetic peptide were evaluated in vitro using head kidney macrophages from gilthead seabream (Sparus aurata L., Perciformes, Sparidae) and rainbow trout (Oncorhynchus mykiss W., Salmoniformes, Salmonidae). In both species the expression of genes encoding the proinflammatory cytokines interleukin-1β (IL-1β) and tumour necrosis factor-α (TNF-α), and the chemokine IL-8, was induced upon stimulation of macrophages with the D1 domain synthetic peptide. IL-1β and IL-8 were the most upregulated genes and to a lesser extent TNF-α. Interestingly, however, the induction activity of the synthetic peptide was higher in gilthead seabream than in rainbow trout macrophages. The results were confirmed at the protein levels for IL-8. Collectively, these results suggest that synthetic peptide derived from flagelling could be a promising approach for the immunostimulation and vaccination of farmed fish.
authors.affiliation: Grupo de Marcadores Inmunológicos, Laboratorio de Genética e Inmunología Molecular, Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile; Laboratorio de Biotecnología y Patología Acuática, Instituto de Patología Animal, Universidad Austral de Chile, Valdivia, Chile; Centro FONDAP, Interdisciplinary Center for Aquaculture Research (INCAR), Chile. Electronic address: rgstegmaier@gmail.com.
authors.forename: Roxana
authors.initials: R
authors.lastname: González-Stegmaier
authors.affiliation: Núcleo de Biotecnología Curauma (NBC), Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile.
authors.forename: Fanny
authors.initials: F
authors.lastname: Guzmán
authors.affiliation: Institute for Research in Biomedicine, and CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine, Barcelona Science Park, Barcelona, Spain; Department of Organic Chemistry, University of Barcelona, Barcelona, Spain; School of Chemistry, Yachay Tech, Yachay City of Knowledge, 100199, Urcuqui, Ecuador.
authors.forename: Fernando
authors.initials: F
authors.lastname: Albericio
authors.affiliation: Instituto de Bioquímica y Microbiología, Universidad Austral de Chile, Valdivia, Chile; Escuela de Tecnología Médica, Universidad Santo Tomas, Valdivia, Chile.
authors.forename: Franz
authors.initials: F
authors.lastname: Villarroel-Espíndola
authors.affiliation: Laboratorio de Biotecnología y Patología Acuática, Instituto de Patología Animal, Universidad Austral de Chile, Valdivia, Chile; Centro FONDAP, Interdisciplinary Center for Aquaculture Research (INCAR), Chile.
authors.forename: Alex
authors.initials: A
authors.lastname: Romero
authors.affiliation: Department of Cell Biology and Histology, Faculty of Biology, University of Murcia, IMIB-Arrixaca, 30100, Murcia, Spain.
authors.forename: Victoriano
authors.initials: V
authors.lastname: Mulero
authors.affiliation: Grupo de Marcadores Inmunológicos, Laboratorio de Genética e Inmunología Molecular, Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile. Electronic address: lmercado@ucv.cl.
authors.forename: Luis
authors.initials: L
authors.lastname: Mercado
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016207:Cytokines / Q000235:genetics* / Q000378:metabolism; D029941:Fish Proteins / Q000235:genetics* / Q000378:metabolism; D005408:Flagellin / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D007113:Immunity, Innate; D008264:Macrophages / Q000276:immunology; D017686:Oncorhynchus mykiss / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D021541:Sea Bream / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D015854:Up-Regulation; D014733:Vibrio / Q000235:genetics / Q000502:physiology*
chemical_list: D016207:Cytokines; D029941:Fish Proteins; D005408:Flagellin; C416532:flaB flagellin
keywords: Cytokines; Fish immunology; Flagellin; Immunomodulatory peptide; TLR5