title: Dietary β-glucans differentially modulate immune and stress-related gene expression in lymphoid organs from healthy and Aeromonas hydrophila-infected rainbow trout (Oncorhynchus mykiss).
abstract: Although β-glucans stimulating effects have already been demonstrated on the immune system of numerous animal species, available data remain relatively variable and more research should be done regarding the complexity of underlying mechanisms. In this context, the present study aimed to evaluate the stress and immune-related effects of dietary β-glucans (i.e. Macrogard®) by considering a number of influencing factors such as the dose (0, 0.1, 0.2 and 0.5% in food), feeding duration (15 versus 30 days), tissue (blood, kidney, spleen, gills) and infection status (healthy or infected). Blood parameters (lysozyme, ACH50 activities, leucocyte populations) and mRNA expression level of several immune- and stress-related genes (TFN-α1, IL-1β, IL10, COX-2, TGF-β, MC2R, HSP70) were measured. Our results suggest that spleen may be a highly responsive organ to dietary β-glucans both in healthy or infected fish, and that this organ may therefore significantly contribute to the immune reinforcement induced by such immunostimulatory diet. Our study further reveals that overdoses of β-glucans and/or prolonged medication can lead to a non-reactive physiological status and, consequently, to a poor immune response. All in all, the current data emphasizes the need for further extensive research in the field of dietary β-glucans as a preventive method for farmed fish protection.
authors.affiliation: Research Unit in Environmental and Evolutionary Biology, University of Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium.
authors.forename: Jessica
authors.initials: J
authors.lastname: Douxfils
authors.affiliation: Department of Cell Biology, Physiology and Immunology, Universitat Autonoma de Barcelona, 08193 Barcelona, Spain.
authors.forename: Camino
authors.initials: C
authors.lastname: Fierro-Castro
authors.affiliation: Research Unit in Environmental and Evolutionary Biology, University of Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium.
authors.forename: S N M
authors.initials: SN
authors.lastname: Mandiki
authors.affiliation: Research Unit in Environmental and Evolutionary Biology, University of Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium.
authors.forename: Wakson
authors.initials: W
authors.lastname: Emile
authors.affiliation: Department of Cell Biology, Physiology and Immunology, Universitat Autonoma de Barcelona, 08193 Barcelona, Spain.
authors.forename: Lluis
authors.initials: L
authors.lastname: Tort
authors.affiliation: Research Unit in Environmental and Evolutionary Biology, University of Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium. Electronic address: patrick.kestemont@unamur.be.
authors.forename: Patrick
authors.initials: P
authors.lastname: Kestemont
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage / Q000494:pharmacology*; D016980:Aeromonas hydrophila / Q000502:physiology; D000821:Animal Feed / Q000032:analysis; D000818:Animals; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements / Q000032:analysis; D005393:Fish Diseases / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D016905:Gram-Negative Bacterial Infections / Q000235:genetics / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D007113:Immunity, Innate; D017686:Oncorhynchus mykiss; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D014018:Tissue Distribution; D047071:beta-Glucans / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D000276:Adjuvants, Immunologic; D029941:Fish Proteins; D047071:beta-Glucans
keywords: Aeromonas; Diet; Gene expression; Immunity; Immunostimulant; Infection; Rainbow trout; β-glucans