title: Ultrapure LPS induces inflammatory and antibacterial responses attenuated in vitro by exogenous sera in Atlantic cod and Atlantic salmon.
abstract: Phagocyte recognition of lipopolysaccharide (LPS) is an early key event for triggering the host innate immune response necessary for clearance of invading bacteria. The ability of fishes to recognise LPS has been questioned as contradictory results have been presented. We show here that monocyte/macrophage cultures from Atlantic cod (Gadus morhua) and Atlantic salmon (Salmo salar) respond with an increased expression of inflammatory and antibacterial genes to both crude and ultrapure Escherichia coli LPS. Crude LPS produces higher induction than the ultrapure LPS type in both species in vitro as well as in vivo in cod injected with LPS. Crude LPS gave, in contrast to ultrapure LPS, an additional weak up-regulation of antiviral genes in salmon macrophages, most likely because of contaminants in the LPS preparation. Increased levels of chicken (c)-type lysozyme transcripts and enzyme activity were measured in salmon macrophages following ultrapure LPS stimulation demonstrating not only increased transcription but also translation. Simultaneous use and even pre-treatment with bovine sera suppressed the LPS-induced expression thereby reflecting the presence of transcription inhibitory components in sera. Together, these findings show that both cod and salmon recognise LPS per se and that the observed induction is highly dependent on the absence of sera.
authors: Norwegian College of Fishery Science, The Arctic University of Norway, P.O. Box 6050, 9037 Tromsø, Norway. Electronic address: marit.seppola@uit.no.
authors: Marit
authors: M
authors: Seppola
authors: The Northern Norway Regional Health Authority, P.O. Box 6426, 9294 Tromsø, Norway.
authors: Helene
authors: H
authors: Mikkelsen
authors: Nofima, P.O. Box 6122, 9291 Tromsø, Norway.
authors: Audny
authors: A
authors: Johansen
authors: Nofima, P.O. Box 6122, 9291 Tromsø, Norway.
authors: Kari
authors: K
authors: Steiro
authors: Nofima, P.O. Box 6122, 9291 Tromsø, Norway.
authors: Bjørnar
authors: B
authors: Myrnes
authors: MAIN Biotechnology, 9020 Tromsø, Norway.
authors: Inge W
authors: IW
authors: Nilsen
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000378:metabolism*; D004926:Escherichia coli / Q000502:physiology; D029941:Fish Proteins / Q000235:genetics* / Q000378:metabolism; D048389:Gadus morhua / Q000235:genetics / Q000276:immunology*; D005786:Gene Expression Regulation; D007113:Immunity, Innate; D008070:Lipopolysaccharides / Q000276:immunology*; D008264:Macrophages / Q000276:immunology; D009113:Muramidase / Q000378:metabolism; D020317:Salmo salar / Q000235:genetics / Q000276:immunology*
chemical_list: D000900:Anti-Bacterial Agents; D029941:Fish Proteins; D008070:Lipopolysaccharides; D009113:Muramidase
keywords: Crude LPS; Innate immune response; Serum inhibitors; Teleosts; Ultrapure LPS