title: High density lipoproteins down-regulate transcriptional expression of pro-inflammatory factors and oxidative burst in head kidney leukocytes from rainbow trout, Oncorhynchus mykiss.
abstract: Teleosts are the first group of vertebrates possessing an acquired immune system; however, it is less developed than in mammals and is highly influenced by environmental changes. Therefore, innate immunity effectors play a more critical role in survival of pathogen-challenged fish. In a previous study we showed that trout high density lipoprotein (HDL), and its major apolipoprotein (ApoA-I) are widely expressed in primary defense barriers and other immune-relevant tissues, displaying important antibacterial activity in vitro. Here we show that trout HDL inhibits both basal and LPS-induced transcript expression of pro-inflammatory cytokines such as TNF-α and IL-1β, and the acute phase protein serum amyloid A (A-SAA), in head kidney leukocytes (HLK) from rainbow trout. In addition, trout HDL was able to block the respiratory burst of PMA-stimulated HKL, at physiological concentrations and in a dose dependent manner. Moreover, this effect was only partially mimicked by supra-physiologic concentrations of the HDL-transported carotenoid, astaxanthin. These results constitute the first data suggesting that in addition to its antimicrobial activity, HDL would have a relevant immunomodulatory role in salmonid fish.
authors.affiliation: Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Campus Isla Teja, Universidad Austral de Chile, Valdivia, Chile. franz.villarroel@postgrado.uach.cl
authors.forename: Franz
authors.initials: F
authors.lastname: Villarroel
authors.forename: Alin
authors.initials: A
authors.lastname: Casado
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Amthauer
authors.forename: Margarita I
authors.initials: MI
authors.lastname: Concha
mesh_terms: D000818:Animals; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation; D004926:Escherichia coli / Q000502:physiology; D060226:Head Kidney / Q000276:immunology*; D007962:Leukocytes / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000502:physiology; D008075:Lipoproteins, HDL / Q000235:genetics* / Q000378:metabolism; D017686:Oncorhynchus mykiss / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D016897:Respiratory Burst; D000685:Serum Amyloid A Protein / Q000235:genetics / Q000378:metabolism
chemical_list: D016207:Cytokines; D008070:Lipopolysaccharides; D008075:Lipoproteins, HDL; D000685:Serum Amyloid A Protein