title: Defensive response of European sea bass (Dicentrarchus labrax) against Listonella anguillarum or Photobacterium damselae subsp. piscicida experimental infection.
abstract: Sea bass were experimentally infected with Listonella anguillarum or Photobacterium damselae subsp. piscicida (Phdp). At 24 and 72h post-infection, the expression analysis of immune-relevant genes (IL-1β, IL-6, IL-8, Hepcidin), the transcriptional level and detection of HSP70, and the quantification of serum iron were investigated in association with the histological analysis and the bacterial recognition in tissues by immunohistochemistry. At 15 days post-infection, the specific antibody response was detected in surviving fish, as well as the transcriptional levels of TcR and BcR sequences. Both experimental infections were characterized by a similar acute response, whereas different histological and immunohistochemistry evidences were observed. In particular, the early reaction appeared suitable for the clearance of L. anguillarum, thus limiting the histological lesions, the bacterial dissemination and the further development of acquired immunity in surviving fish. On the contrary, the innate response appeared not enough to resolve the Phdp infection, which was characterized by tissue damage, bacterial widespread and substantial detection of specific humoral immunity in surviving fish, also associated to lymphocytes clonal expansion. Besides the opportunistic conditions involved in fish vibriosis and pasteurellosis, the comparison between these experimental infection models seems to suggest that the rate of development of the acquired immunity is strictly linked to the activation of the host innate response combined to the degree of bacterial virulence.
authors.affiliation: Faculty of Veterinary Medicine, University of Teramo, Piazza A. Moro 45, 64100 Teramo, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Mosca
authors.affiliation: Department of Veterinary Medical Sciences, University of Bologna, Viale Vespucci 2, 47042 Cesenatico, FC, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Ciulli
authors.affiliation: Section of Veterinary Pathology, Department of Food Science, University of Udine, Via Sondrio 2/a, 33100 Udine, Italy.
authors.forename: Donatella
authors.initials: D
authors.lastname: Volpatti
authors.affiliation: Functional Comparative Anatomy & Developmental Biology, Dept. Ecology & Biology, Block D, University of Tuscia, 01100 Viterbo, Italy.
authors.forename: Nicla
authors.initials: N
authors.lastname: Romano
authors.affiliation: Department of Veterinary Medical Sciences, University of Bologna, Viale Vespucci 2, 47042 Cesenatico, FC, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Volpe
authors.affiliation: Section of Veterinary Pathology, Department of Food Science, University of Udine, Via Sondrio 2/a, 33100 Udine, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Bulfon
authors.affiliation: Faculty of Veterinary Medicine, University of Teramo, Piazza A. Moro 45, 64100 Teramo, Italy.
authors.forename: Marcella
authors.initials: M
authors.lastname: Massimini
authors.affiliation: Functional Comparative Anatomy & Developmental Biology, Dept. Ecology & Biology, Block D, University of Tuscia, 01100 Viterbo, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Caccia
authors.affiliation: Section of Veterinary Pathology, Department of Food Science, University of Udine, Via Sondrio 2/a, 33100 Udine, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Galeotti
authors.affiliation: Faculty of Veterinary Medicine, University of Teramo, Piazza A. Moro 45, 64100 Teramo, Italy. Electronic address: pgtiscar@unite.it.
authors.forename: Pietro G
authors.initials: PG
authors.lastname: Tiscar
mesh_terms: D000818:Animals; D001492:Bass; D005393:Fish Diseases / Q000276:immunology / Q000382:microbiology*; D015964:Gene Expression Regulation, Bacterial / Q000276:immunology*; D016905:Gram-Negative Bacterial Infections / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000276:immunology; D060226:Head Kidney / Q000276:immunology; D064451:Hepcidins / Q000235:genetics / Q000276:immunology; D007150:Immunohistochemistry / Q000662:veterinary; D007378:Interleukins / Q000235:genetics / Q000276:immunology; D053526:Listonella / Q000276:immunology*; D010776:Photobacterium / Q000276:immunology*; D012313:RNA / Q000737:chemistry / Q000235:genetics; D011897:Random Allocation; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D013154:Spleen / Q000276:immunology; D013950:Thymus Gland / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000276:immunology
chemical_list: D018840:HSP70 Heat-Shock Proteins; D064451:Hepcidins; D007378:Interleukins; D014409:Tumor Necrosis Factor-alpha; D012313:RNA
keywords: Acute response; Adaptive immunity; Infection; Sea bass