title: Differential Modulation of IgT and IgM upon Parasitic, Bacterial, Viral, and Dietary Challenges in a Perciform Fish.
abstract: Three different immunoglobulin (Ig) isotypes can be found in teleost fish, IgM, IgD, and the teleost-specific IgT. IgM is considered to have a systemic activity, and IgT is attributed a mucosal role, similar to mammalian IgA. In this study, the complete sequence of gilthead sea bream IgM and IgT in their membrane (m) and soluble (s) forms are described for the first time in a perciform fish. Their constitutive gene expression is analyzed in different tissues, and their regulation upon viral, bacterial, parasitic, mucosal vaccination and dietary challenges are studied. GCB IgM and IgT have the prototypical structure when compared to other fish Igs. The constitutive expression ofsIgMwas the highest overall in all tissues, whereasmIgTexpression was highest in mucosal tissues, such as gills and intestine.IgMandIgTwere differentially regulated upon infection.IgTwas highly upregulated locally upon infection with the intestinal parasiteEnteromyxum leeior systemically after Nodavirus infection. Long-term intestinal parasitic infections increased the serum titer of both isotypes. Mucosal vaccination againstPhotobacterium damselaesubsp.piscicidafinely regulated the Ig response inducing a systemic increase of IgM titers in serum and a local IgT response in skin mucus when animals were exposed to the pathogen by bath challenge. Interestingly, plant-based diets inhibit IgT upregulation upon intestinal parasitic challenge, which was related to a worse disease outcome. All these results corroborate the mucosal role of IgT and emphasize the importance of a finely tuned regulation of Ig isotypes upon infection, which could be of special interest in vaccination studies.
authors.affiliation: Instituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC) , Castellón , Spain.
authors.forename: Maria C
authors.initials: MC
authors.lastname: Piazzon
authors.affiliation: Department of Cell Biology and Histology, Faculty of Biology, Biomedical Research Institute of Murcia (IMIB-Arrixaca-UMU), University of Murcia , Murcia , Spain.
authors.forename: Jorge
authors.initials: J
authors.lastname: Galindo-Villegas
authors.affiliation: Instituto de Investigaciones Marinas, Consejo Superior de Investigaciones Científicas (IIM-CSIC) , Vigo , Spain.
authors.forename: Patricia
authors.initials: P
authors.lastname: Pereiro
authors.affiliation: Instituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC) , Castellón , Spain.
authors.forename: Itziar
authors.initials: I
authors.lastname: Estensoro
authors.affiliation: Instituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC) , Castellón , Spain.
authors.forename: Josep A
authors.initials: JA
authors.lastname: Calduch-Giner
authors.affiliation: Department of Biotechnology, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) , Madrid , Spain.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Gómez-Casado
authors.affiliation: Instituto de Investigaciones Marinas, Consejo Superior de Investigaciones Científicas (IIM-CSIC) , Vigo , Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Novoa
authors.affiliation: Department of Cell Biology and Histology, Faculty of Biology, Biomedical Research Institute of Murcia (IMIB-Arrixaca-UMU), University of Murcia , Murcia , Spain.
authors.forename: Victoriano
authors.initials: V
authors.lastname: Mulero
authors.affiliation: Instituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC) , Castellón , Spain.
authors.forename: Ariadna
authors.initials: A
authors.lastname: Sitjà-Bobadilla
authors.affiliation: Instituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC) , Castellón , Spain.
authors.forename: Jaume
authors.initials: J
authors.lastname: Pérez-Sánchez
keywords: IgM; IgT; Sparus aurata; fish; immunoglobulins; infectious diseases; myxozoa; nutrition