title: Dietary β-glucan stimulate complement and C-reactive protein acute phase responses in common carp (Cyprinus carpio) during an Aeromonas salmonicida infection.
abstract: The effect of β-glucans as feed additive on the profile of C-reactive protein (CRP) and complement acute phase responses was studied in common carp Cyprinus carpio after exposition to a bacterial infection with Aeromonas salmonicida. Carp were orally administered with β-glucan (MacroGard®) for 14 days with a daily β-glucan intake of 6 mg per kg body weight. Fish were then intraperitoneally injected with either PBS or 1 × 10⁸ bacteria per fish and sampled at time 0, 6, 12, 24, 48, 72, 96 and 120 h post-injection (p.i.) for serum and head kidney, liver and mid-gut tissues. CRP levels and complement activity were determined in the serum samples whilst the gene expression profiles of CRP and complement related genes (crp1, crp2, c1r/s, bf/c2, c3 and masp2) were analysed in the tissues by quantitative PCR. Results obtained showed that oral administration of β-glucan for 14 days significantly increased serum CRP levels up to 2 fold and serum alternative complement activity (ACP) up to 35 fold. The bacterial infection on its own (i.e. not combined with a β-glucan feeding) did have significant effects on complement response whilst CRP was not detectably induced during the carp acute phase reaction. However, the combination of the infection and the β-glucan feeding did show significant effects on both CRP and complement profiles with higher serum CRP levels and serum ACP activity in the β-glucan fed fish than in the control fed fish. In addition, a distinct organ and time dependent expression profile pattern was detected for all the selected genes: a peak of gene expression first occurred in the head kidney tissue (6 h p.i. or 12 h p.i.), then an up-regulation in the liver several hours later (24 h p.i.) and finally up- or down-regulations in the mid-gut at 24 h p.i. and 72 h p.i. In conclusion, the results of this study suggest that MacroGard® stimulated CRP and complement responses to A. salmonicida infection in common carp.
authors.affiliation: Institute of Science and Technology in Medicine, School of Life Sciences, Keele University, ST5 5BG Keele, United Kingdom.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Pionnier
authors.forename: Alberto
authors.initials: A
authors.lastname: Falco
authors.forename: Joanna
authors.initials: J
authors.lastname: Miest
authors.forename: Patrick
authors.initials: P
authors.lastname: Frost
authors.forename: Ilgiz
authors.initials: I
authors.lastname: Irnazarow
authors.forename: Annette
authors.initials: A
authors.lastname: Shrive
authors.forename: Dave
authors.initials: D
authors.lastname: Hoole
mesh_terms: D000210:Acute-Phase Reaction / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D048409:Aeromonas salmonicida / Q000276:immunology; D000818:Animals; D002097:C-Reactive Protein / Q000378:metabolism*; D002347:Carps; D019587:Dietary Supplements / Q000032:analysis; D005393:Fish Diseases / Q000276:immunology* / Q000382:microbiology; D020869:Gene Expression Profiling / Q000662:veterinary; D005786:Gene Expression Regulation; D016905:Gram-Negative Bacterial Infections / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D007113:Immunity, Innate; D007274:Injections, Intraperitoneal / Q000662:veterinary; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D047071:beta-Glucans / Q000276:immunology*
chemical_list: D047071:beta-Glucans; D002097:C-Reactive Protein