An investigation of the immunotoxicity of oil sands processed water and leachates in trout leukocytes.
Increased oil sands (OS) mining activity has raised concerns about impacts on aquatic organisms. This study sought to examine the effects of single representative compounds from OS (benzo(a)pyrene, naphthalene), a mixture of naphthenic acids (NAs), OS-processed water (OSPW) and OS leachate (OSL) extracts on rainbow trout leukocytes. Primary cultures of trout leukocytes were exposed to increasing concentrations of benzo(a)pyrene, naphthalene, NAs, OSPW and OSL for 48h at 18°C. Immunocompetence was followed by measuring changes in lymphocyte and macrophage viability and phagocytosis. Changes in the expression of 10 transcripts were also followed: interleukin 1, 2 and 6 (Il-1, Il-2 and Il-6), calreticulin (CRT), caspase 9 (Cas9), aryl hydrocarbon receptor (AhR), cyclooxygenase-2 (COX2), glutathione S-transferase (GST), catalase (CAT) and p53 tumor suppressor. The results revealed that exposure to OSPW extracts decreased the capacity of macrophages to engulf three beads or more, while the other compounds generally increased phagocytosis activity. Lymphocyte apoptosis was increased by all compounds and mixtures except naphthalene. Both OSPW and OSL induced apoptosis in macrophages. At the gene expression level, Cas9, CRT, Il-1 (inhibition) and Il-2 were specifically influenced by OSPW, while CAT, p53, COX2 and Il-1 (induction) transcripts were specifically expressed by OSL. Leukocyte exposure to OSPW produced characteristic changes in immunocompetence and genes involved in proinflammatory, apoptosis and protein damage (CRT) pathways which could not be explained by OSL, benzo(a)pyrene, naphthalene and NA mixture.
Aquatic Contaminants Research Division, Water Science and Technology, Environment and Climate Change Canada, Montreal, Quebec H2Y 2E7, Canada. Electronic address: francois.gagne@canada.ca.
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Gagné
Aquatic Contaminants Research Division, Water Science and Technology, Environment and Climate Change Canada, Montreal, Quebec H2Y 2E7, Canada.
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Bruneau
Aquatic Contaminants Research Division, Water Science and Technology, Environment and Climate Change Canada, Montreal, Quebec H2Y 2E7, Canada.
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Turcotte
Aquatic Contaminants Research Division, Water Science and Technology, Environment and Climate Change Canada, Montreal, Quebec H2Y 2E7, Canada.
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Gagnon
INRS-Institut Armand-Frappier, 531 des Prairies, Laval, Quebec H7V 1B7, Canada.
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Lacaze
D000818:Animals; D001564:Benzo(a)pyrene / Q000737:chemistry / Q000633:toxicity; D002264:Carboxylic Acids / Q000737:chemistry / Q000633:toxicity; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D007962:Leukocytes / Q000187:drug effects* / Q000276:immunology*; D008264:Macrophages / Q000187:drug effects / Q000276:immunology; D008906:Mining; D061329:Oil and Gas Fields; D017686:Oncorhynchus mykiss / Q000097:blood* / Q000235:genetics / Q000276:immunology; D010587:Phagocytosis / Q000187:drug effects / Q000276:immunology; D061251:Primary Cell Culture; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity*
D002264:Carboxylic Acids; D014874:Water Pollutants, Chemical; D001564:Benzo(a)pyrene; C046170:naphthenic acid
Gene expression; Immunocompetence; Inflammation; Oil sands processed water; Oxidative stress