Modulation of the early immune response against viruses by a teleostean interferon regulatory factor-1 (IRF-1).
We investigated the role of a teleostean interferon regulatory factor-1 (IRF-1) in the regulation of the fish immune system using Japanese flounder, Paralichthys olivaceus, as a model. Fish were intramuscularly vaccinated with a recombinant plasmid expressing the Japanese flounder IRF-1 (JF IRF-1) under the control of the cytomegalovirus immediate/early enhancer (CMV) promoter and were sampled at different days post-immunization. Peripheral blood leukocytes (PBLs) obtained from the JF IRF-1-vaccinated fish during the early stages post-vaccination had significantly elevated levels of nitric oxide (NO) and higher acid phosphatase (AP) activity compared with the control groups. Moreover, supernatants of PBLs obtained from the IRF-1-vaccinated fish contained cytokine-like substances as shown by their protective effect against hirame rhabdovirus (HIRRV) and viral hemorrhagic septicemia virus (VHSV) in two cell lines, hirame natural embryo (HINAE) cell line and epithelial papillosum of cyprini (EPC) cell line. Relative expression of an anti-viral gene, Mx was highest at the 7th day post-vaccination. Co-injection of JF IRF-1 with a DNA vaccine encoding the major capsid protein (MCP) gene of red seabream iridovirus (RSIV) resulted in elevated serum neutralization antibodies but was not significantly different from that in the fish vaccinated with the DNA vaccine alone. These results suggest that the JF IRF-1 modulates the early immune response in fish and is a potential candidate as genetic adjuvant for vaccination.
Caipang
Christopher Marlowe A
CM
Laboratory of Genome Science, Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato, Tokyo 108-8477, Japan. cmacaipang@yahoo.com
Hirono
Ikuo
I
Aoki
Takashi
T
D000135:Acid Phosphatase / Q000276:immunology; D000818:Animals; D002460:Cell Line; D003587:Cytomegalovirus / Q000276:immunology*; D005432:Flounder / Q000276:immunology*; D050856:Interferon Regulatory Factor-1 / Q000235:genetics / Q000276:immunology*; D007962:Leukocytes / Q000276:immunology; D009569:Nitric Oxide / Q000096:biosynthesis / Q000276:immunology; D029141:Novirhabdovirus / Q000276:immunology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019444:Vaccines, DNA / Q000008:administration & dosage; D014765:Viral Vaccines / Q000276:immunology*
D050856:Interferon Regulatory Factor-1; D019444:Vaccines, DNA; D014765:Viral Vaccines; D009569:Nitric Oxide; D000135:Acid Phosphatase