title: Enhancing gilthead seabream immune status and protection against bacterial challenge by means of antigens derived from Vibrio parahaemolyticus.
abstract: In an attempt to control the proliferation of the pathogenic bacterium Vibrio parahaemolyticus in gilthead seabream (Sparus aurata), the immunostimulant effect of lysate and ToxA from this bacterium was evaluated. Fish were intraperitoneally injected twice (first injection, day 1 of the experiment; second injection, day 7) and sampled after one week (on days 8 and 15). Afterwards, all fish specimens were experimentally infected with V. parahaemolyticus and mortality was recovered for 1 week. Fish injected with lysate, ToxA and phosphate buffer saline (control) showed 100%, 50% and 0% survival, respectively, when challenged with the pathogen. Skin mucus immune parameters and immune-related gene expression in skin and spleen were also evaluated. The results showed that mucus immune parameters were enhanced in the lysate and ToxA groups compared with the values obtained for fish from the control group. Expression of IL-1β, TNF-α, C3 and IgM genes was significantly up-regulated in the lysate and ToxA groups, principally after infection with the bacterium. Interestingly, TLR5 gene expression increased in fish immunized with lysate. The most prominent histological characteristic in gut from infected fish was the presence of a great number of intraepithelial leucocytes as well as inflammation of the submucosa, while severe hydropic degeneration and hemosiderosis were detected in liver from infected fish. Injection of lysate or ToxA had a protective effect against the deleterious consequences of subsequent infection with V. parahaemolyticus in gut and liver. The findings underline the potential of lysate and ToxA as potent preventive antigens against this kind of vibriosis.
authors.affiliation: Immunology & Vaccinology Group, Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Instituto Politécnico Nacional 195, Playa Palo de Santa Rita Sur, La Paz, B.C.S. 23090, Mexico.
authors.forename: Martha
authors.initials: M
authors.lastname: Reyes-Becerril
authors.affiliation: Immunology & Vaccinology Group, Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Instituto Politécnico Nacional 195, Playa Palo de Santa Rita Sur, La Paz, B.C.S. 23090, Mexico.
authors.forename: Crystal
authors.initials: C
authors.lastname: Guluarte
authors.affiliation: Fish Innate Immune System Group, Department of Cell Biology & Histology, Faculty of Biology, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, Spain.
authors.forename: Diana
authors.initials: D
authors.lastname: Ceballos-Francisco
authors.affiliation: Immunology & Vaccinology Group, Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Instituto Politécnico Nacional 195, Playa Palo de Santa Rita Sur, La Paz, B.C.S. 23090, Mexico. Electronic address: eangulo@cibnor.mx.
authors.forename: Carlos
authors.initials: C
authors.lastname: Angulo
authors.affiliation: Fish Innate Immune System Group, Department of Cell Biology & Histology, Faculty of Biology, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, Spain. Electronic address: aesteban@um.es.
authors.forename: M Ángeles
authors.initials: MÁ
authors.lastname: Esteban
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001427:Bacterial Toxins / Q000008:administration & dosage / Q000276:immunology*; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000276:immunology*; D005393:Fish Diseases / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D015870:Gene Expression; D007113:Immunity, Innate / Q000187:drug effects; D007274:Injections, Intraperitoneal / Q000662:veterinary; D009093:Mucus / Q000276:immunology; D021541:Sea Bream; D012867:Skin / Q000276:immunology; D014735:Vibrio Infections / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary*; D014736:Vibrio parahaemolyticus / Q000276:immunology*
chemical_list: D000276:Adjuvants, Immunologic; D001427:Bacterial Toxins; D001428:Bacterial Vaccines
keywords: Gene expression; Gilthead seabream; Lysate; Mucosal immunity; PirA-like; ToxA; Vibrio parahaemolyticus