title: Cell-mediated immune responses in rainbow trout after DNA immunization against the viral hemorrhagic septicemia virus.
abstract: To identify viral proteins that induce cell-mediated cytotoxicity (CMC) against viral hemorrhagic septicemia virus (VHSV)-infected cells, rainbow trout were immunized with DNA vectors encoding the glycoprotein G or the nucleocapsid protein N of VHSV. The G protein was a more potent trigger of cytotoxic cells than the N protein. Peripheral blood leukocytes (PBL) isolated from trout immunized against the G protein killed both VHSV-infected MHC class I matched (RTG-2) and VHSV-infected xenogeneic (EPC) target cells, suggesting the involvement of both cytotoxic T lymphocytes (CTL) and NK cells, respectively. In contrast, PBL from trout that were immunized against the N protein only killed VHSV-infected RTG-2 cells, indicating that this protein only elicits a CTL response. Further, a significant killing capacity of these PBL was only observed during summer months. PBL from fish that were immunized against the VHSV G protein significantly killed VHSV-infected but not infectious hematopoietic necrosis virus (IHNV)-infected targets indicating antigen specificity. Thus, this is the first report on cytotoxic immune responses after DNA vaccination in fish. Furthermore, cells isolated from the inflamed site of DNA injection were stained and transferred to isogeneic DNA-vaccinated recipients. Most of the stained donor leukocytes accumulated at the recipients' DNA injection site showing, for the first time, leukocyte homing in fish. Transferred donor leukocytes mainly migrated to the homologous vaccine injection site rather than to injection sites of heterologous vaccines, suggesting the antigen specificity of homing. By demonstrating CMC responses to distinct viral proteins and homing in rainbow trout, these results substantially contribute to the understanding of the teleost immune system.
authors.affiliation: Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, D-17493 Greifswald-Insel Riems, Germany.
authors.forename: Katrin
authors.initials: K
authors.lastname: Utke
authors.forename: Holger
authors.initials: H
authors.lastname: Kock
authors.forename: Heike
authors.initials: H
authors.lastname: Schuetze
authors.forename: Sven M
authors.initials: SM
authors.lastname: Bergmann
authors.forename: Niels
authors.initials: N
authors.lastname: Lorenzen
authors.forename: Katja
authors.initials: K
authors.lastname: Einer-Jensen
authors.forename: Bernd
authors.initials: B
authors.lastname: Köllner
authors.forename: Roy A
authors.initials: RA
authors.lastname: Dalmo
authors.forename: Tomas
authors.initials: T
authors.lastname: Vesely
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Ototake
authors.forename: Uwe
authors.initials: U
authors.lastname: Fischer
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D000917:Antibody Formation / Q000276:immunology; D016827:CD8 Antigens / Q000235:genetics; D002460:Cell Line; D015870:Gene Expression; D031941:Hemorrhagic Septicemia, Viral / Q000276:immunology* / Q000517:prevention & control; D007111:Immunity, Cellular / Q000276:immunology*; D007155:Immunologic Factors / Q000235:genetics; D007273:Injections, Intramuscular; D007962:Leukocytes / Q000166:cytology / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000378:metabolism; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism; D029141:Novirhabdovirus / Q000276:immunology*; D009698:Nucleoproteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D017686:Oncorhynchus mykiss / Q000276:immunology*; D010957:Plasmids / Q000235:genetics; D012621:Seasons; D013154:Spleen / Q000166:cytology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014162:Transfection; D014611:Vaccination / Q000379:methods; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D014764:Viral Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism
chemical_list: D016827:CD8 Antigens; C431698:CD8alpha antigen; C096089:G protein, viral hemorrhagic septicemia virus; D007155:Immunologic Factors; D009698:Nucleoproteins; D019444:Vaccines, DNA; D014759:Viral Envelope Proteins; D014764:Viral Proteins