title: Negative effects of low dose atrazine exposure on the development of effective immunity to FV3 in Xenopus laevis.
abstract: The recent dramatic increase of the prevalence and range of amphibian host species and populations infected by ranaviruses such as Frog Virus 3 (FV3) raises concerns about the efficacies of amphibian antiviral immunity. In this context, the potential negative effects of water contaminants such as the herbicide atrazine, at environmentally relevant levels, on host antiviral immunity remains unclear. Here we describe the use of the amphibian Xenopus laevis as an ecotoxicology platform to elucidate the consequences of exposure to ecologically relevant doses of atrazine on amphibian antiviral immunity. X. laevis were exposed at tadpole and adult stages as well as during metamorphosis to atrazine (range from 0.1 to 10.0 ppb) prior to infection with FV3. Quantitative analysis of gene expression revealed significant changes in the pro-inflammatory cytokine, TNF-α and the antiviral type I IFN gene in response to FV3 infection. This was most marked in tadpoles that were exposed to atrazine at doses as low 0.1 ppb. Furthermore, atrazine exposure significantly compromised tadpole survival following FV3 infections. In contrast, acute atrazine exposure of mature adult frogs did not induce detectable effects on anti-FV3 immunity, but adults that were exposed to atrazine during metamorphosis exhibited pronounced defects in FV3-induced TNF-α gene expression responses and slight diminution in type I IFN gene induction. Thus, even at low doses, atrazine exposure culminates in impaired development of amphibian antiviral defenses.
authors.affiliation: Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Sifkarovski
authors.affiliation: Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, USA.
authors.forename: Leon
authors.initials: L
authors.lastname: Grayfer
authors.affiliation: Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, USA.
authors.forename: Francisco
authors.initials: F
authors.lastname: De Jesús Andino
authors.affiliation: Department of Environmental Medicine, University of Rochester Medical Center, Rochester, USA; Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, USA.
authors.forename: B Paige
authors.initials: BP
authors.lastname: Lawrence
authors.affiliation: Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, USA. Electronic address: Jacques_Robert@urmc.rochester.edu.
authors.forename: Jacques
authors.initials: J
authors.lastname: Robert
mesh_terms: D000818:Animals; D001280:Atrazine / Q000633:toxicity*; D016207:Cytokines / Q000235:genetics / Q000276:immunology*; D005786:Gene Expression Regulation / Q000187:drug effects; D006540:Herbicides / Q000633:toxicity; D017995:Ranavirus / Q000502:physiology*; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D014982:Xenopus laevis / Q000254:growth & development / Q000276:immunology*
chemical_list: D016207:Cytokines; D006540:Herbicides; D014874:Water Pollutants, Chemical; D001280:Atrazine
keywords: Antiviral immunity; Immune toxicant; Ranavirus; Water pollutants