title: In vitro immunotoxicological effects of heavy metals on European sea bass (Dicentrarchus labrax L.) head-kidney leucocytes.
abstract: The knowledge about the direct effects of heavy metals on fish leucocytes is still limited. We investigate the in vitro effects of heavy metals (Cd, Hg, Pb or As) on oxidative stress, viability and innate immune parameters of head-kidney leucocytes (HKLs) from European sea bass (Dicentrarchus labrax). Production of free oxygen radicals was induced by Cd, Hg and As, mainly after 30 min of exposure. Cd and Hg promoted both apoptosis and necrosis cell death while Pb and As did only apoptosis, in all cases in a concentration-dependent manner. Moreover, expression of genes related to oxidative stress and apoptosis was significantly induced by Hg and Pb but down-regulated by As. In addition, the expression of the metallothionein A gene was up-regulated by Cd and Pb exposure though this transcript, as well as the heat shock protein 70, was down-regulated by Hg. Cd, methylmercury (MeHg) and As reduced the phagocytic ability, whereas Hg and Pb increased it. Interestingly, all the heavy metals decreased the phagocytic capacity (the number of ingested particles per cell). Leucocyte respiratory burst changed depending on the metal exposure, usually in a time- and dose-manner. Interestingly, the expression of immune-related genes was slightly affected by Cd, MeHg, As or Pb being Hg the form producing the greatest alterations, which included down-regulation of immunoglobulin M and hepcidin, as well as the up-regulation of interleukin-1 beta mRNA levels. This study provides an in vitro approach for elucidating the heavy metals toxicity, and particularly the immunotoxicity, in fish leucocytes.
authors.affiliation: Fish Innate Immune System Group, Department of Cell Biology and Histology, Faculty of Biology, Campus Regional de Excelencia Internacional "Campus Mare Nostrum", University of Murcia, 30100 Murcia, Spain.
authors.forename: Patricia
authors.initials: P
authors.lastname: Morcillo
authors.affiliation: Fish Innate Immune System Group, Department of Cell Biology and Histology, Faculty of Biology, Campus Regional de Excelencia Internacional "Campus Mare Nostrum", University of Murcia, 30100 Murcia, Spain.
authors.forename: Héctor
authors.initials: H
authors.lastname: Cordero
authors.affiliation: Fish Innate Immune System Group, Department of Cell Biology and Histology, Faculty of Biology, Campus Regional de Excelencia Internacional "Campus Mare Nostrum", University of Murcia, 30100 Murcia, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Meseguer
authors.affiliation: Fish Innate Immune System Group, Department of Cell Biology and Histology, Faculty of Biology, Campus Regional de Excelencia Internacional "Campus Mare Nostrum", University of Murcia, 30100 Murcia, Spain.
authors.forename: M Ángeles
authors.initials: MÁ
authors.lastname: Esteban
authors.affiliation: Fish Innate Immune System Group, Department of Cell Biology and Histology, Faculty of Biology, Campus Regional de Excelencia Internacional "Campus Mare Nostrum", University of Murcia, 30100 Murcia, Spain. Electronic address: alcuesta@um.es.
authors.forename: Alberto
authors.initials: A
authors.lastname: Cuesta
mesh_terms: D000818:Animals; D001151:Arsenic / Q000633:toxicity*; D001492:Bass / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D060226:Head Kidney / Q000276:immunology; D000922:Immunotoxins / Q000633:toxicity; D007962:Leukocytes / Q000276:immunology; D019216:Metals, Heavy / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects; D010587:Phagocytosis / Q000187:drug effects; D016897:Respiratory Burst / Q000187:drug effects; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D029941:Fish Proteins; D000922:Immunotoxins; D019216:Metals, Heavy; D014874:Water Pollutants, Chemical; D001151:Arsenic
keywords: Apoptosis; European sea bass; Heavy metals; Oxidative stress; Phagocytosis; ROS