title: Differential immune gene expression profiles in susceptible and resistant full-sibling families of Atlantic salmon (Salmo salar) challenged with infectious pancreatic necrosis virus (IPNV).
abstract: This study aims to identify at the expression level the immune-related genes associated with IPN-susceptible and resistant phenotypes in Atlantic salmon full-sibling families. We have analyzed thirty full-sibling families infected by immersion with IPNV and then classified as resistant or susceptible using a multivariate survival analysis based on a gamma-Cox frailty model and the Kaplan-Meier mortality curves. In four families within each group head kidneys were pooled for real-time PCR and one-color salmon-specific oligonucleotide microarray (21K) analysis at day 1 and 5 post-infection. Transcripts involved in innate response (IL-6, IFN-α), antigen presentation (HSP-70, HSP-90, MHC-I), TH1 response (IL-12, IFN-γ, CRFB6), immunosuppression (IL-10, TGF-β1) and leukocyte activation and migration (CCL-19, CD18) showed a differential expression pattern between both phenotypes, except in IL-6. In susceptible families, except for IFN-γ, the expressions dropped to basal values at day 5 post-infection. In resistant families, unlike susceptible families, levels remained high or increased (except for IL-6) at day 5. Transcriptomic analysis showed that both families have a clear differential expression pattern, resulting in a marked down-regulation in immune related genes involved in innate response, complement system, antigen recognition and activation of immune response in IPN-resistant. Down-regulation of genes, mainly related to tissue differentiation and protein degradation metabolism, was also observed in resistant families. We have identified an immune-related gene patterns associated with susceptibility and resistance to IPNV infection of Atlantic salmon. This suggests that a limited immune response is associated with resistant fish phenotype to IPNV challenge while a highly inflammatory but short response is associated with susceptibility.
authors.affiliation: Laboratorio de Inmunología, Centro de Biotecnología Acuícola, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Alameda 3363, Correo 40, Casilla 33, Santiago, Chile; Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain. Electronic address: Felipe.Reyes@uab.cat.
authors.forename: Felipe E
authors.initials: FE
authors.lastname: Reyes-López
authors.affiliation: Departamento de Matemática y Ciencia de la Computación, Universidad de Santiago de Chile, Alameda 3363, Correo 40, Casilla 33, Santiago, Chile.
authors.forename: Jose S
authors.initials: JS
authors.lastname: Romeo
authors.affiliation: Laboratorio de Virología, Centro de Biotecnología Acuícola, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Alameda 3363, Correo 40, Casilla 33, Santiago, Chile; Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
authors.forename: Eva
authors.initials: E
authors.lastname: Vallejos-Vidal
authors.affiliation: Laboratorio de Inmunología, Centro de Biotecnología Acuícola, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Alameda 3363, Correo 40, Casilla 33, Santiago, Chile.
authors.forename: Sebastián
authors.initials: S
authors.lastname: Reyes-Cerpa
authors.affiliation: Laboratorio de Virología, Centro de Biotecnología Acuícola, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Alameda 3363, Correo 40, Casilla 33, Santiago, Chile.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Sandino
authors.affiliation: Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
authors.forename: Lluis
authors.initials: L
authors.lastname: Tort
authors.affiliation: Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain; Institute of Aquaculture, University of Stirling, FK9 4LA Stirling, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Mackenzie
authors.affiliation: Laboratorio de Inmunología, Centro de Biotecnología Acuícola, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Alameda 3363, Correo 40, Casilla 33, Santiago, Chile. Electronic address: monica.imarai@usach.cl.
authors.forename: Mónica
authors.initials: M
authors.lastname: Imarai
mesh_terms: D000818:Animals; D018175:Birnaviridae Infections / Q000276:immunology* / Q000821:virology; D003165:Complement System Proteins / Q000235:genetics / Q000276:immunology; D060467:Disease Resistance / Q000235:genetics* / Q000276:immunology; D004198:Disease Susceptibility / Q000276:immunology; D005393:Fish Diseases / Q000276:immunology* / Q000821:virology; D020869:Gene Expression Profiling; D060226:Head Kidney / Q000276:immunology; D007113:Immunity, Innate / Q000235:genetics / Q000276:immunology; D018061:Infectious pancreatic necrosis virus / Q000276:immunology*; D020317:Salmo salar / Q000235:genetics / Q000276:immunology* / Q000821:virology
chemical_list: D003165:Complement System Proteins
keywords: Full-sibling families; IPN-Resistance; Immune response; Microarrays; Salmo salar; Transcriptomics