Molecular cloning and characterization of Toll-like receptor 3 in Japanese flounder, Paralichthys olivaceus.
Mammalian Toll-like receptor 3 (TLR3) recognizes extracellular and intracellular viral dsRNA, and then initiates signaling cascades leading to NF-κB activation and interferon (IFN) production. To understand the roles of TLR3 in the fish immune system, TLR3 gene (JfTLR3) was identified from Japanese flounder (Paralichthys olivaceus), which consisted of 4 exons and 3 introns. Its expression in peripheral blood leukocytes increased upon stimulation with poly I:C and CpG ODN 1668. Exposure to viral hemorrhagic septicemia virus increased expression of JfTLR3 in the blood, liver, head kidney and spleen. Intracellular poly I:C stimulation in JfTLR3-overexpressing YO-K cells significantly induced IFN-inducible and NF-κB-regulated genes. NF-κB activity in JfTLR3-overexpressing YO-K cells was significantly induced by intracellular poly I:C while expression of IFN-inducible genes and NF-κB reporter activity in JfTLR3-overexpressing HINAE cells increased upon stimulation by extracellular poly I:C. These results suggest that JfTLR3 plays an important role in the induction of antiviral immune response.
Laboratory of Genome Science, Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato-ku, Tokyo 108-8477, Japan.
Seong Don
SD
Hwang
Maki
M
Ohtani
Jun-ichi
J
Hikima
Tae Sung
TS
Jung
Hidehiro
H
Kondo
Ikuo
I
Hirono
Takashi
T
Aoki
D000595:Amino Acid Sequence; D000818:Animals; D002478:Cells, Cultured; D003001:Cloning, Molecular; D029941:Fish Proteins / Q000819:agonists / Q000235:genetics* / Q000378:metabolism; D005432:Flounder / Q000235:genetics* / Q000276:immunology; D015870:Gene Expression; D005786:Gene Expression Regulation; D007369:Interferon Inducers / Q000494:pharmacology; D007372:Interferons / Q000378:metabolism; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000378:metabolism; D009928:Organ Specificity; D010802:Phylogeny; D011070:Poly I-C / Q000494:pharmacology; D018353:Rhabdoviridae Infections / Q000276:immunology / Q000662:veterinary; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D051196:Toll-Like Receptor 3 / Q000819:agonists / Q000235:genetics* / Q000378:metabolism
D029941:Fish Proteins; D007369:Interferon Inducers; D016328:NF-kappa B; D051196:Toll-Like Receptor 3; D007372:Interferons; D011070:Poly I-C