title: Identification and expression analysis of lymphotoxin-beta like homologues in rainbow trout Oncorhynchus mykiss.
abstract: A lymphotoxin-beta (LT-beta) gene has been cloned and sequenced in rainbow trout and provides the first conclusive evidence for the existence of LT-beta in teleost. Two isoforms of LT-beta were isolated. LT-beta1 cDNA was composed of 952 bp (with a 139 bp 5'-UTR and a 201 bp 3'-UTR) and LT-beta2 cDNA was 836 bp (with a 237 bp 5'-UTR and a 197 bp 3'-UTR) both of which translated into a protein of 203 amino acid residues. Both isoforms contained a predicted transmembrane domain of 21 amino acid residues (Leu11-Val31) and the TNF family signature (Val104-Phe120). Homology and phylogenetic analysis of trout LT-beta's with other known TNF family member showed good similarity to TNF-N (teleost) and other LT-beta (mammals and frog). LT-beta1 and TNF-alpha (1 and 2) genes were highly expressed in unstimulated trout head kidney, spleen, gill and intestine, whereas LT-beta2 was weakly expressed only in the gill. The expression of LT-beta1 and -beta2 genes was not found in macrophage (RTS-11) and fibroblast (RTG-2) like cell lines, although the TNF-alpha2 gene was expressed in both cell lines with the TNF-alpha1 gene only expressed in RTS-11 cells. In head kidney cells, expression of LT-beta1 and TNF-alpha (1, 2) genes was increased by stimulation with PHA or LPS. The discovery of trout LT-beta will allow a more complete analysis of fish inflammatory responses.
authors.affiliation: Department of Marine Biotechnology, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuen Kibanadai-nishi, Miyazaki 889-2192, Japan.
authors.forename: Tomoya
authors.initials: T
authors.lastname: Kono
authors.forename: Jun
authors.initials: J
authors.lastname: Zou
authors.forename: Steve
authors.initials: S
authors.lastname: Bird
authors.forename: Ram
authors.initials: R
authors.lastname: Savan
authors.forename: Masahiro
authors.initials: M
authors.lastname: Sakai
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Secombes
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D016207:Cytokines / Q000494:pharmacology; D018076:DNA, Complementary / Q000235:genetics; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics*; D015870:Gene Expression / Q000187:drug effects; D008233:Lymphotoxin-alpha / Q000737:chemistry / Q000235:genetics*; D053308:Lymphotoxin-beta; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D017686:Oncorhynchus mykiss / Q000235:genetics* / Q000276:immunology*; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
chemical_list: D000276:Adjuvants, Immunologic; D016207:Cytokines; D018076:DNA, Complementary; D029941:Fish Proteins; D008233:Lymphotoxin-alpha; D053308:Lymphotoxin-beta; D008565:Membrane Proteins; D014409:Tumor Necrosis Factor-alpha