title: Flagellin from Marinobacter algicola and Vibrio vulnificus activates the innate immune response of gilthead seabream.
abstract: Adjuvants have emerged as the best tools to enhance the efficacy of vaccination. However, the traditional adjuvants used in aquaculture may cause adverse alterations in fish making necessary the development of new adjuvants able to stimulate the immune system and offer strong protection against infectious pathogens with minimal undesirable effects. In this respect, flagellin seems an attractive candidate due to its ability to strongly stimulate the immune response of fish. In the present study, we have evaluated the ability of recombinant flagellin from Marinobacter algicola (MA) and Vibrio vulnificus (Vvul), a non-pathogenic and a pathogenic bacteria, respectively, to stimulate the innate immune system of gilthead seabream (Sparus aurata L.) and compare the effect with that of the classical flagellin from Salmonella enterica serovar Typhimurium (Salmonella Typhimurium, STF). Intraperitoneal injection of MA and Vvul resulted in a strong inflammatory response characterized by increased reactive oxygen species production and the infiltration of acidophilic granulocytes at the injection site. Interestingly, however, only flagellin from MA consistently induced the expression of the gene encoding pro-inflammatory interleukin-1β. These effects were further confirmed in vitro, where a dose-dependent activation of macrophages and acidophilic granulocytes by MA and Vvul flagellins was observed. In contrast, STF flagellin was found to be less potent in both in vivo and in vitro experiments. Our results suggest the potential use of MA and Vvul flagellins as immunostimulants and adjuvants for fish vaccination.
authors.affiliation: Department of Cell Biology and Histology, Faculty of Biology, University of Murcia and IMIB-Arrixaca, Murcia, Spain.
authors.forename: Jana
authors.initials: J
authors.lastname: Montero
authors.affiliation: Department of Biotechnology, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid, Spain.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Gómez-Casado
authors.affiliation: Oceanographic Centre of Murcia, Spanish Oceanographic Institute (IEO), Puerto de Mazarrón, Murcia, Spain.
authors.forename: Alicia
authors.initials: A
authors.lastname: García-Alcázar
authors.affiliation: Department of Cell Biology and Histology, Faculty of Biology, University of Murcia and IMIB-Arrixaca, Murcia, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Meseguer
authors.affiliation: Department of Cell Biology and Histology, Faculty of Biology, University of Murcia and IMIB-Arrixaca, Murcia, Spain. Electronic address: vmulero@um.es.
authors.forename: Victoriano
authors.initials: V
authors.lastname: Mulero
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D000818:Animals; D017756:Aquaculture; D001424:Bacterial Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000276:immunology; D005393:Fish Diseases / Q000276:immunology / Q000517:prevention & control*; D005408:Flagellin / Q000008:administration & dosage*; D007113:Immunity, Innate; D053520:Marinobacter / Q000737:chemistry*; D010586:Phagocytes / Q000276:immunology; D021541:Sea Bream / Q000276:immunology*; D041261:Vibrio vulnificus / Q000737:chemistry*
chemical_list: D000276:Adjuvants, Immunologic; D001428:Bacterial Vaccines; D005408:Flagellin
keywords: Adjuvant; Fish; Flagellin; Immunostimulants; Seabream; Teleosts