title: The adjuvant effect of low frequency ultrasound when applied with an inactivated Aeromonas salmonicida vaccine to rainbow trout (Oncorhynchus mykiss).
abstract: Vaccine adjuvants are classified according to their properties of either inducing the persistence of antigens within the animal after immunisation and/or activation of the animal's immune response. The adjuvant effect of low intensity low frequency sonophoresis (LFS) was tested in rainbow trout using an Aeromonas salmonicida bacterin vaccine administered by immersion vaccination using LFS at 37 kHz. The adjuvant effect obtained with LFS was compared with that of normal immersion or intraperitoneal injection vaccination. Quantitative PCR was used to measure bacterial DNA in vaccinated fish up to 35 days post-vaccination, while RT-qPCR was used to assess gene expression during the early and late immune response post-vaccination. Results showed that antigen uptake in the gills was significantly higher in the group exposed to low intensity LFS compared to the other two vaccination groups 15 min post-vaccination, but this initially high uptake did not persist over the rest of the experiment. In the kidney, by comparison, the vast majority of the samples analysed did not show the presence or persistence of the bacterin. Showing that the route of vaccine uptake using the A. salmonicida bacterin, does not influence the persistence of the bacterin in the gills or the kidney. On the other hand, LFS induced a higher inflammatory response and T-helper cell activation, characterized by a significant up-regulation of interleukin-8 (IL-8), IL-1ß and CD-4, respectively. The expression of Ig-M, Ig-T and Ig-D was up-regulated in gills (being significant for Ig-M), but not in the spleen and kidney of the sonicated group. Conversely, Ig-M was up-regulated in the spleen of the non-sonicated groups, but not in the sonicated group. This highlights the ability of ultrasound to enhance mucosal immunity. It remains to be established whether the up-regulation of Ig-M in gills would be sufficient to offer protection in fish infected with A. salmonicida.
authors.affiliation: Department of Ecophysiology and Aquaculture, Leibniz-Institute of Freshwater Ecology and Inland, Fisheries, Berlin 12587, Germany; Faculty of Life Sciences, Humboldt University of Berlin, Berlin 10115, Germany. Electronic address: cristobalvet@hotmail.com.
authors.forename: Cristóbal
authors.initials: C
authors.lastname: Cobo Labarca
authors.affiliation: Department of Ecophysiology and Aquaculture, Leibniz-Institute of Freshwater Ecology and Inland, Fisheries, Berlin 12587, Germany.
authors.forename: Mary
authors.initials: M
authors.lastname: Makhutu
authors.affiliation: Leibniz-Institute of Freshwater Ecology and Inland Fisheries, 12587 Berlin, Germany; Department of Biology, Chemistry and Pharmacy, Freie Universität, Berlin, 14195, Germany.
authors.forename: Alexander E
authors.initials: AE
authors.lastname: Lumsdon
authors.affiliation: Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Near Edinburgh, Scotland, UK.
authors.forename: Kim D
authors.initials: KD
authors.lastname: Thompson
authors.affiliation: Bandeli Nandelin Electronic GmbH & Co. KG, Berlin 12207, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Jung
authors.affiliation: Department of Ecophysiology and Aquaculture, Leibniz-Institute of Freshwater Ecology and Inland, Fisheries, Berlin 12587, Germany; Department of Endocrinology, Institute of Biology, Humboldt University, Berlin, Germany.
authors.forename: Werner
authors.initials: W
authors.lastname: Kloas
authors.affiliation: Department of Ecophysiology and Aquaculture, Leibniz-Institute of Freshwater Ecology and Inland, Fisheries, Berlin 12587, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Knopf
mesh_terms: D000276:Adjuvants, Immunologic; D048409:Aeromonas salmonicida / Q000276:immunology*; D000818:Animals; D001428:Bacterial Vaccines / Q000276:immunology*; D004269:DNA, Bacterial; D005393:Fish Diseases / Q000517:prevention & control*; D029941:Fish Proteins; D005667:Furunculosis / Q000517:prevention & control*; D015870:Gene Expression; D005880:Gills / Q000276:immunology; D007101:Immersion; D007072:Immunoglobulin D / Q000235:genetics; D007075:Immunoglobulin M / Q000235:genetics; D007136:Immunoglobulins / Q000235:genetics; D007274:Injections, Intraperitoneal; D016209:Interleukin-8 / Q000235:genetics / Q000276:immunology; D007668:Kidney; D017686:Oncorhynchus mykiss / Q000276:immunology*; D060888:Real-Time Polymerase Chain Reaction; D013154:Spleen / Q000276:immunology; D000069453:Ultrasonic Waves; D014611:Vaccination; D015164:Vaccines, Inactivated / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D001428:Bacterial Vaccines; D004269:DNA, Bacterial; D029941:Fish Proteins; D007072:Immunoglobulin D; D007075:Immunoglobulin M; D007136:Immunoglobulins; D016209:Interleukin-8; D015164:Vaccines, Inactivated; C569864:immunoglobulin T, teleost
keywords: Bacterin; DIP; Fish; Immersion; Sonophoresis