title: Identification of CD3ε, CD4, CD8β splice variants of Atlantic salmon.
abstract: In vertebrates, CD3 complex and CD4 and CD8 co-receptors are essential for signal transduction during T cell activation. In the present study, we report the mRNA spliced variants of the Atlantic salmon CD3ε, CD4 and CD8β and the effect of pathogen encounter on the expression of these variants. CD3ε is alternatively spliced in thymus, head kidney, spleen and gills to give rise to the complete mRNA sequence and to an alternative product that lacks the transmembrane exon. CD4 is also alternatively spliced in the thymus, head kidney, spleen and gills to form two variants, although the alternative product is barely detectable. The alternative product lacks the exon 1B encoding the D1 domain, which is essential for binding to MHC class II proteins. Two amplicons were also found for the CD8β gene; sequencing analysis revealed that the main PCR product corresponds to the previously reported CD8β sequence, whereas the variant sequence encodes a potential protein that lacks the Ig-like domain. The expression of CD3, CD4, CD8β genes also analyzed in head kidney of LPS-treated and IPNV infected salmon and different patterns of expression were observed. The presence and balance of the different variants of T cell co-receptors could be related to the ability of fish to induce a particular type of immune response, as well as, the ability of the pathogen to modify the fish immune response.
authors.affiliation: Laboratorio de Inmunología, Centro de Biotecnología Acuícola (CBA), Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Alameda 3363, Correo 40, Casilla 33, Santiago, Chile.
authors.forename: Kevin
authors.initials: K
authors.lastname: Maisey
authors.forename: Daniela
authors.initials: D
authors.lastname: Toro-Ascuy
authors.forename: Ruth
authors.initials: R
authors.lastname: Montero
authors.forename: Felipe E
authors.initials: FE
authors.lastname: Reyes-López
authors.forename: Mónica
authors.initials: M
authors.lastname: Imarai
mesh_terms: D000818:Animals; D001483:Base Sequence; D018175:Birnaviridae Infections / Q000276:immunology / Q000378:metabolism / Q000662:veterinary*; D017252:CD3 Complex / Q000235:genetics* / Q000276:immunology; D015704:CD4 Antigens / Q000235:genetics* / Q000276:immunology; D016827:CD8 Antigens / Q000235:genetics* / Q000276:immunology; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D005393:Fish Diseases / Q000276:immunology* / Q000378:metabolism; D005880:Gills / Q000378:metabolism; D060226:Head Kidney / Q000378:metabolism; D018061:Infectious pancreatic necrosis virus; D008969:Molecular Sequence Data; D020033:Protein Isoforms / Q000235:genetics* / Q000276:immunology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D020317:Salmo salar / Q000235:genetics*; D017422:Sequence Analysis, DNA / Q000662:veterinary; D013154:Spleen / Q000378:metabolism; D013950:Thymus Gland / Q000378:metabolism
chemical_list: D017252:CD3 Complex; D015704:CD4 Antigens; D016827:CD8 Antigens; C477867:CD8beta antigen; D017931:DNA Primers; D018076:DNA, Complementary; D020033:Protein Isoforms; D012333:RNA, Messenger