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Dalton CS, Tomaselli M, Rothenburger JL, Mavrot F, Di Francesco J, Leclerc LM, Ytrehus B, Checkley S, Kutz S, Abdul-Careem MF, van der Meer F. Detection and Phylogenetic Analysis of Orf Virus and Muskox Rhadinovirus 1 from Muskoxen (Ovibos moschatus) in the Canadian Arctic. J Wildl Dis 2024; 60:461-473. [PMID: 38334201 DOI: 10.7589/jwd-d-22-00170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 12/19/2023] [Indexed: 02/10/2024]
Abstract
Orf virus (genus Parapoxvirus) has been associated with gross skin lesions on muskoxen (Ovibos moschatus) from Victoria Island, Nunavut, Canada, where muskox populations are experiencing population declines. Orf virus causes painful proliferative and necrotizing dermatitis upon viral replication and shedding, which may lead to animal morbidity or mortality through secondary infections and starvation. Herpesvirus, known to cause gross lesions on skin and mucosa during active viral replication, has also been documented in muskoxen but to date has not been associated with clinical disease. Our objective was to characterize the variation of orf virus and herpesvirus in wild muskoxen of the Canadian Arctic. Tissue samples including gross skin lesions from the nose, lips, and/or legs were opportunistically collected from muskoxen on Victoria Island, Nunavut and Northwest Territories, and mainland Nunavut, Canada, from 2015 to 2017. Sampled muskoxen varied in age, sex, location, hunt type, and body condition. Tissues from 60 muskoxen were tested for genetic evidence of orf virus and herpesvirus infection using PCR targeting key viral genes. Tissues from 38 muskoxen, including 15 with gross lesions, were also examined for histological evidence of orf virus and herpesvirus infection. Eleven muskoxen (10 from Victoria Island and one from mainland Nunavut) with gross lesions had microscopic lesions consistent with orf virus infection. Muskox rhadinovirus 1, a gammaherpesvirus endemic to muskoxen, was detected in 33 (55%) muskoxen including 17 with gross lesions. In all tissues examined, there was no histological evidence of herpesvirus-specific disease. Sequencing and characterization of amplified PCR products using phylogenetic analysis indicated that a strain of orf virus, which appears to be unique, is likely to be endemic in muskoxen from Victoria Island and mainland Nunavut. Many of the muskoxen are also subclinically infected with a known muskox-endemic strain of herpesvirus.
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Affiliation(s)
- Chimoné Stefni Dalton
- Faculty of Veterinary Medicine, University of Calgary, 3280 Hospital Dr. NW, Calgary, Alberta T2N 4Z6, Canada
| | - Matilde Tomaselli
- Faculty of Veterinary Medicine, University of Calgary, 3280 Hospital Dr. NW, Calgary, Alberta T2N 4Z6, Canada
- Polar Knowledge Canada, Canadian High Arctic Research Station, 1 Uvajuq Rd., P.O. Box 2150, Cambridge Bay, Nunavut X0B 0C0, Canada
| | - Jamie L Rothenburger
- Faculty of Veterinary Medicine, University of Calgary, 3280 Hospital Dr. NW, Calgary, Alberta T2N 4Z6, Canada
- Canadian Wildlife Health Cooperative (Alberta Region), Faculty of Veterinary Medicine, University of Calgary, 3280 Hospital Dr. NW, Calgary, Alberta T2N 4Z6, Canada
| | - Fabien Mavrot
- Faculty of Veterinary Medicine, University of Calgary, 3280 Hospital Dr. NW, Calgary, Alberta T2N 4Z6, Canada
| | - Juliette Di Francesco
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California Davis, Davis, California 95616, USA
| | - Lisa-Marie Leclerc
- Department of Environment, Government of Nunavut, P.O. 377, Kugluktuk, Nunavut X0B 0E0, Canada
| | - Bjørnar Ytrehus
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Box 7036, 750 07 Uppsala, Sweden
| | - Sylvia Checkley
- Faculty of Veterinary Medicine, University of Calgary, 3280 Hospital Dr. NW, Calgary, Alberta T2N 4Z6, Canada
| | - Susan Kutz
- Faculty of Veterinary Medicine, University of Calgary, 3280 Hospital Dr. NW, Calgary, Alberta T2N 4Z6, Canada
- Canadian Wildlife Health Cooperative (Alberta Region), Faculty of Veterinary Medicine, University of Calgary, 3280 Hospital Dr. NW, Calgary, Alberta T2N 4Z6, Canada
| | - Mohamed Faizal Abdul-Careem
- Faculty of Veterinary Medicine, University of Calgary, 3280 Hospital Dr. NW, Calgary, Alberta T2N 4Z6, Canada
| | - Frank van der Meer
- Faculty of Veterinary Medicine, University of Calgary, 3280 Hospital Dr. NW, Calgary, Alberta T2N 4Z6, Canada
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2
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Dietz R, Letcher RJ, Aars J, Andersen M, Boltunov A, Born EW, Ciesielski TM, Das K, Dastnai S, Derocher AE, Desforges JP, Eulaers I, Ferguson S, Hallanger IG, Heide-Jørgensen MP, Heimbürger-Boavida LE, Hoekstra PF, Jenssen BM, Kohler SG, Larsen MM, Lindstrøm U, Lippold A, Morris A, Nabe-Nielsen J, Nielsen NH, Peacock E, Pinzone M, Rigét FF, Rosing-Asvid A, Routti H, Siebert U, Stenson G, Stern G, Strand J, Søndergaard J, Treu G, Víkingsson GA, Wang F, Welker JM, Wiig Ø, Wilson SJ, Sonne C. A risk assessment review of mercury exposure in Arctic marine and terrestrial mammals. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 829:154445. [PMID: 35304145 DOI: 10.1016/j.scitotenv.2022.154445] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/25/2022] [Accepted: 03/06/2022] [Indexed: 06/14/2023]
Abstract
There has been a considerable number of reports on Hg concentrations in Arctic mammals since the last Arctic Monitoring and Assessment Programme (AMAP) effort to review biological effects of the exposure to mercury (Hg) in Arctic biota in 2010 and 2018. Here, we provide an update on the state of the knowledge of health risk associated with Hg concentrations in Arctic marine and terrestrial mammal species. Using available population-specific data post-2000, our ultimate goal is to provide an updated evidence-based estimate of the risk for adverse health effects from Hg exposure in Arctic mammal species at the individual and population level. Tissue residues of Hg in 13 species across the Arctic were classified into five risk categories (from No risk to Severe risk) based on critical tissue concentrations derived from experimental studies on harp seals and mink. Exposure to Hg lead to low or no risk for health effects in most populations of marine and terrestrial mammals, however, subpopulations of polar bears, pilot whales, narwhals, beluga and hooded seals are highly exposed in geographic hotspots raising concern for Hg-induced toxicological effects. About 6% of a total of 3500 individuals, across different marine mammal species, age groups and regions, are at high or severe risk of health effects from Hg exposure. The corresponding figure for the 12 terrestrial species, regions and age groups was as low as 0.3% of a total of 731 individuals analyzed for their Hg loads. Temporal analyses indicated that the proportion of polar bears at low or moderate risk has increased in East/West Greenland and Western Hudson Bay, respectively. However, there remain numerous knowledge gaps to improve risk assessments of Hg exposure in Arctic mammalian species, including the establishment of improved concentration thresholds and upscaling to the assessment of population-level effects.
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Affiliation(s)
- Rune Dietz
- Aarhus University, Arctic Research Centre (ARC), Department of Ecoscience, P.O. Box 358, DK-4000 Roskilde, Denmark.
| | - Robert J Letcher
- Ecotoxicology and Wildlife Health Division, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON K1A 0H3, Canada.
| | - Jon Aars
- Norwegian Polar Institute, Tromsø NO-9296, Norway
| | | | - Andrei Boltunov
- Marine Mammal Research and Expedition Centre, 36 Nahimovskiy pr., Moscow 117997, Russia
| | - Erik W Born
- Greenland Institute of Natural Resources, P.O. Box 570, DK-3900 Nuuk, Greenland
| | - Tomasz M Ciesielski
- Department of Biology, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Krishna Das
- Freshwater and Oceanic sciences Unit of reSearch (FOCUS), University of Liege, 4000 Liege, Belgium
| | - Sam Dastnai
- Aarhus University, Arctic Research Centre (ARC), Department of Ecoscience, P.O. Box 358, DK-4000 Roskilde, Denmark
| | - Andrew E Derocher
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
| | - Jean-Pierre Desforges
- Aarhus University, Arctic Research Centre (ARC), Department of Ecoscience, P.O. Box 358, DK-4000 Roskilde, Denmark; Department of Environmental Studies and Science, University of Winnipeg, Winnipeg, MB, Canada
| | - Igor Eulaers
- Aarhus University, Arctic Research Centre (ARC), Department of Ecoscience, P.O. Box 358, DK-4000 Roskilde, Denmark; Norwegian Polar Institute, Tromsø NO-9296, Norway
| | - Steve Ferguson
- Fisheries and Oceans Canada, 501 University Crescent, Winnipeg, MB R3T 2N6, Canada; Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | | | | | - Lars-Eric Heimbürger-Boavida
- Géosciences Environnement Toulouse, CNRS/IRD/Université Paul Sabatier Toulouse III, Toulouse, France; Aix Marseille Université, CNRS/INSU, Université de Toulon, IRD, Mediterranean Institute of Oceanography (MIO) UM 110, Marseille, France
| | | | - Bjørn M Jenssen
- Aarhus University, Arctic Research Centre (ARC), Department of Ecoscience, P.O. Box 358, DK-4000 Roskilde, Denmark; Department of Biology, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Stephen Gustav Kohler
- Department of Chemistry, Norwegian University of Science and Technology, Realfagbygget, E2-128, Gløshaugen, NO-7491 Trondheim, Norway
| | - Martin M Larsen
- Aarhus University, Arctic Research Centre (ARC), Department of Ecoscience, P.O. Box 358, DK-4000 Roskilde, Denmark
| | - Ulf Lindstrøm
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, NO-9037 Tromsø, Norway; Department of Arctic Technology, Institute of Marine Research, FRAM Centre, NO-9007 Tromsø, Norway
| | - Anna Lippold
- Norwegian Polar Institute, Tromsø NO-9296, Norway
| | - Adam Morris
- Northern Contaminants Program, Crown-Indigenous Relations and Northern Affairs Canada, 15 Eddy Street, 14th floor, Gatineau, Quebec K1A 0H4, Canada
| | - Jacob Nabe-Nielsen
- Aarhus University, Arctic Research Centre (ARC), Department of Ecoscience, P.O. Box 358, DK-4000 Roskilde, Denmark
| | - Nynne H Nielsen
- Greenland Institute of Natural Resources, P.O. Box 570, DK-3900 Nuuk, Greenland
| | - Elizabeth Peacock
- USGS Alaska Science Center, 4210 University Dr., Anchorage, AK 99508-4626, USA
| | - Marianna Pinzone
- Department of Environmental Studies and Science, University of Winnipeg, Winnipeg, MB, Canada
| | - Frank F Rigét
- Aarhus University, Arctic Research Centre (ARC), Department of Ecoscience, P.O. Box 358, DK-4000 Roskilde, Denmark
| | - Aqqalu Rosing-Asvid
- Greenland Institute of Natural Resources, P.O. Box 570, DK-3900 Nuuk, Greenland
| | - Heli Routti
- Norwegian Polar Institute, Tromsø NO-9296, Norway
| | - Ursula Siebert
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstr. 6, DE-25761 Büsum, Germany
| | - Garry Stenson
- Northwest Atlantic Fisheries Centre, Department DFO-MPO, 80 EastWhite Hills vie, St John's A1C 5X1, Newfoundland and Labrador, Canada
| | - Gary Stern
- Centre for Earth Observation Sciences (CEOS), Clayton H. Riddell Faculty of Environment, Earth and Resources, University of Manitoba, 586Wallace Bld, 125 Dysart Rd., Winnipeg, Manitoba R3T, 2N2, Canada
| | - Jakob Strand
- Aarhus University, Arctic Research Centre (ARC), Department of Ecoscience, P.O. Box 358, DK-4000 Roskilde, Denmark
| | - Jens Søndergaard
- Aarhus University, Arctic Research Centre (ARC), Department of Ecoscience, P.O. Box 358, DK-4000 Roskilde, Denmark
| | - Gabriele Treu
- Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Str. 17, 10315 Berlin, Germany
| | - Gisli A Víkingsson
- Marine and Freshwater Research Institute, Skúlagata 4, 101 Reykjavík, Iceland
| | - Feiyue Wang
- Centre for Earth Observation Sciences (CEOS), Clayton H. Riddell Faculty of Environment, Earth and Resources, University of Manitoba, 586Wallace Bld, 125 Dysart Rd., Winnipeg, Manitoba R3T, 2N2, Canada
| | - Jeffrey M Welker
- University of Alaska Anchorage, Anchorage 99508, United States; University of Oulu, Oulu 90014, Finland; University of the Arctic, Rovaniemi 96460, Finland
| | - Øystein Wiig
- Natural History Museum, University of Oslo, P.O. Box 1172, Blindern, N-0318 Oslo, Norway
| | - Simon J Wilson
- Arctic Monitoring and Assessment Programme (AMAP) Secretariat, Box 6606 Stakkevollan, N-9296 Tromsø, Norway
| | - Christian Sonne
- Aarhus University, Arctic Research Centre (ARC), Department of Ecoscience, P.O. Box 358, DK-4000 Roskilde, Denmark
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3
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Dietz R, Fort J, Sonne C, Albert C, Bustnes JO, Christensen TK, Ciesielski TM, Danielsen J, Dastnai S, Eens M, Erikstad KE, Galatius A, Garbus SE, Gilg O, Hanssen SA, Helander B, Helberg M, Jaspers VLB, Jenssen BM, Jónsson JE, Kauhala K, Kolbeinsson Y, Kyhn LA, Labansen AL, Larsen MM, Lindstøm U, Reiertsen TK, Rigét FF, Roos A, Strand J, Strøm H, Sveegaard S, Søndergaard J, Sun J, Teilmann J, Therkildsen OR, Thórarinsson TL, Tjørnløv RS, Wilson S, Eulaers I. A risk assessment of the effects of mercury on Baltic Sea, Greater North Sea and North Atlantic wildlife, fish and bivalves. ENVIRONMENT INTERNATIONAL 2021; 146:106178. [PMID: 33246245 DOI: 10.1016/j.envint.2020.106178] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 09/15/2020] [Accepted: 09/30/2020] [Indexed: 06/11/2023]
Abstract
A wide range of species, including marine mammals, seabirds, birds of prey, fish and bivalves, were investigated for potential population health risks resulting from contemporary (post 2000) mercury (Hg) exposure, using novel risk thresholds based on literature and de novo contamination data. The main geographic focus is on the Baltic Sea, while data from the same species in adjacent waters, such as the Greater North Sea and North Atlantic, were included for comparative purposes. For marine mammals, 23% of the groups, each composing individuals of a specific sex and maturity from the same species in a specific study region, showed Hg-concentrations within the High Risk Category (HRC) and Severe Risk Category (SRC). The corresponding percentages for seabirds, fish and bivalves were 2.7%, 25% and 8.0%, respectively, although fish and bivalves were not represented in the SRC. Juveniles from all species showed to be at no or low risk. In comparison to the same species in the adjacent waters, i.e. the Greater North Sea and the North Atlantic, the estimated risk for Baltic populations is not considerably higher. These findings suggest that over the past few decades the Baltic Sea has improved considerably with respect to presenting Hg exposure to its local species, while it does still carry a legacy of elevated Hg levels resulting from high neighbouring industrial and agricultural activity and slow water turnover regime.
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Affiliation(s)
- Rune Dietz
- Aarhus University, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, PO Box 358, 4000 Roskilde, Denmark.
| | - Jérôme Fort
- LIENSs, UMR 7266 CNRS-La Rochelle Université, 2 Rue Olympe de Gouges, 17000 La Rochelle, France
| | - Christian Sonne
- Aarhus University, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, PO Box 358, 4000 Roskilde, Denmark
| | - Céline Albert
- LIENSs, UMR 7266 CNRS-La Rochelle Université, 2 Rue Olympe de Gouges, 17000 La Rochelle, France
| | - Jan Ove Bustnes
- Norwegian Institute for Nature Research (NINA), FRAM Centre, 9296 Tromsø, Norway
| | | | - Tomasz Maciej Ciesielski
- Department of Biology, Norwegian University of Science and Technology, Høgskoleringen 5, 7491 Trondheim, Norway
| | - Jóhannis Danielsen
- The Faroese Marine Research Institute, Nóatún 1, 100 Tórshavn, Faroe Islands
| | - Sam Dastnai
- Aarhus University, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, PO Box 358, 4000 Roskilde, Denmark
| | - Marcel Eens
- Behavioural Ecology & Ecophysiology Group, Department of Biology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Kjell Einar Erikstad
- Norwegian Institute for Nature Research (NINA), FRAM Centre, 9296 Tromsø, Norway
| | - Anders Galatius
- Aarhus University, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, PO Box 358, 4000 Roskilde, Denmark
| | - Svend-Erik Garbus
- Aarhus University, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, PO Box 358, 4000 Roskilde, Denmark
| | - Olivier Gilg
- UMR 6249 Chrono-environnement, Université de Bourgogne Franche-Comté, 16 route de Gray, 25000 Besançon, France; Groupe de Recherche en Ecologie Arctique, 16 rue de Vernot, 21440 Francheville, France
| | - Sveinn Are Hanssen
- Norwegian Institute for Nature Research (NINA), FRAM Centre, 9296 Tromsø, Norway
| | - Björn Helander
- Swedish Museum of Natural History, Department of Contaminant Research, Frescativägen 40, PO Box 50007, 104 18 Stockholm, Sweden
| | - Morten Helberg
- CEES, Department of Biosciences, University of Oslo, PO Box 1066, 0316 Oslo, Norway
| | - Veerle L B Jaspers
- Department of Biology, Norwegian University of Science and Technology, Høgskoleringen 5, 7491 Trondheim, Norway
| | - Bjørn Munro Jenssen
- Aarhus University, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, PO Box 358, 4000 Roskilde, Denmark; Department of Biology, Norwegian University of Science and Technology, Høgskoleringen 5, 7491 Trondheim, Norway
| | - Jón Einar Jónsson
- Northeast Iceland Nature Research Centre, Hafnarstétt 3, 640 Húsavík, Iceland
| | - Kaarina Kauhala
- Natural Resources Institute Finland, LUKE, Itäinen Pitkäkatu 4A, 20520 Turku, Finland
| | - Yann Kolbeinsson
- Northeast Iceland Nature Research Centre, Hafnarstétt 3, 640 Húsavík, Iceland
| | - Line Anker Kyhn
- Aarhus University, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, PO Box 358, 4000 Roskilde, Denmark
| | - Aili Lage Labansen
- Greenland Institute of Natural Resources, Kivioq 2, PO Box 570, 3900 Nuuk, Greenland
| | - Martin Mørk Larsen
- Aarhus University, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, PO Box 358, 4000 Roskilde, Denmark
| | - Ulf Lindstøm
- Institute of Marine Research, FRAM Centre, 9007 Tromsø, Norway; UiT Norwegian Arctic University, Institute of Arctic and Marine Biology, Dramsveien 201, 9037 Tromsø, Norway
| | - Tone K Reiertsen
- Norwegian Institute for Nature Research (NINA), FRAM Centre, 9296 Tromsø, Norway
| | - Frank F Rigét
- Aarhus University, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, PO Box 358, 4000 Roskilde, Denmark
| | - Anna Roos
- Swedish Museum of Natural History, Department of Contaminant Research, Frescativägen 40, PO Box 50007, 104 18 Stockholm, Sweden
| | - Jakob Strand
- Aarhus University, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, PO Box 358, 4000 Roskilde, Denmark
| | - Hallvard Strøm
- Norwegian Polar Institute, FRAM Centre, PO Box 6606 Langnes, 9296 Tromsø, Norway
| | - Signe Sveegaard
- Aarhus University, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, PO Box 358, 4000 Roskilde, Denmark
| | - Jens Søndergaard
- Aarhus University, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, PO Box 358, 4000 Roskilde, Denmark
| | - Jiachen Sun
- Behavioural Ecology & Ecophysiology Group, Department of Biology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium; School of Environment, Jinan University, West Huangpu Avenue 601, 510632 Guangzhou, Guangdong, China
| | - Jonas Teilmann
- Aarhus University, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, PO Box 358, 4000 Roskilde, Denmark
| | | | | | - Rune Skjold Tjørnløv
- Aarhus University, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, PO Box 358, 4000 Roskilde, Denmark
| | - Simon Wilson
- Arctic Monitoring and Assessment Programme (AMAP) Secretariat, FRAM Centre, PO Box 6606 Langnes, 9296 Tromsø, Norway
| | - Igor Eulaers
- Aarhus University, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, PO Box 358, 4000 Roskilde, Denmark
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4
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Peñín I, Levin M, Acevedo-Whitehouse K, Jasperse L, Gebhard E, Gulland FMD, De Guise S. Effects of polychlorinated biphenyls (PCB) on California sea lion (Zalophus californianus) lymphocyte functions upon in vitro exposure. ENVIRONMENTAL RESEARCH 2018; 167:708-717. [PMID: 30236520 DOI: 10.1016/j.envres.2018.08.028] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 08/22/2018] [Accepted: 08/23/2018] [Indexed: 06/08/2023]
Abstract
Polychorinated biphenyl (PCB) congeners are a cause for concern due to their persistence in the environment, their lipophilic properties that cause them to bio-accumulate in top predators, and their adverse effects on mammalian health. For example, the common urogenital carcinoma reported in California sea lions (Zalophus californianus) (CSL) is associated with high tissue levels of PCBs, but the mechanisms responsible for this association are unknown. This study investigated the effect of exposure to six PCB congeners and a congener mix at low and environmentally relevant concentrations on NK cell-like and T cell activity using in vitro assays on cryopreserved lymph node mononuclear cells isolated from dead CSL. Non dioxin-like congeners 153 and 180 increased lymphocyte proliferation at 5 and 10 ppm, while congener 138 decreased proliferation by up to 43% at 15 ppm. Dioxin-like PCBs 118 and 169 did not affect lymphocyte proliferation, while the effects of congener 105 depended on the mitogen concentration; these did not correlate with their predicted toxic equivalent factors. NK cell-like activity was affected only by the highest concentration of PCBs tested; it was increased by non-dioxin-like congeners 138 and 153, and decreased by dioxin-like congener 169. The PCB congener mix suggested that the effects of PCB congeners were not simply additive. Our results concur with effects of PCBs reported for other pinniped's lymphocytes and add further experimental support to the observation that dioxin-like PCBs are not the most toxic congeners for marine mammals, contrary to effects in other species. This is the first evidence of in vitro suppression of NK cell-like cytotoxicity by a dioxin-like congener in a pinniped. More importantly, the observed results suggest that PCBs can modulate the CSL immune system, increasing exposed individuals' susceptibility to viral and oncogenic challenges.
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Affiliation(s)
- I Peñín
- Laboratory of Immune Plasticity and Molecular Ecoepidemiology, Unit for Basic and Applied Microbiology, Autonomous University of Queretaro, 76230, Mexico
| | - M Levin
- Department of Pathobiology and Veterinary Science, University of Connecticut, 61 North Eagleville Road, Storrs, CT 06269, USA
| | - K Acevedo-Whitehouse
- Laboratory of Immune Plasticity and Molecular Ecoepidemiology, Unit for Basic and Applied Microbiology, Autonomous University of Queretaro, 76230, Mexico; The Marine Mammal Center, 2000 Bunker Road, Sausalito, CA 94965, USA
| | - L Jasperse
- Department of Pathobiology and Veterinary Science, University of Connecticut, 61 North Eagleville Road, Storrs, CT 06269, USA
| | - E Gebhard
- Department of Pathobiology and Veterinary Science, University of Connecticut, 61 North Eagleville Road, Storrs, CT 06269, USA
| | - F M D Gulland
- The Marine Mammal Center, 2000 Bunker Road, Sausalito, CA 94965, USA
| | - S De Guise
- Department of Pathobiology and Veterinary Science, University of Connecticut, 61 North Eagleville Road, Storrs, CT 06269, USA.
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