Mercury-Modulated Immune Responses in Arctic Barnacle Goslings (Branta leucopsis) upon a Viral-Like Immune Challenge

Biyao Han, Hans van den Berg, Maarten J.J.E. Loonen, Rafael Mateo, Nico W. van den Brink*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Historical mining activities in Svalbard (79°N/12°E) have caused local mercury (Hg) contamination. To address the potential immunomodulatory effects of environmental Hg on Arctic organisms, we collected newborn barnacle goslings (Branta leucopsis) and herded them in either a control or mining site, differing in Hg levels. An additional group at the mining site was exposed to extra inorganic Hg(II) via supplementary feed. Hepatic total Hg concentrations differed significantly between the control (0.011 ± 0.002 mg/kg dw), mine (0.043 ± 0.011 mg/kg dw), and supplementary feed (0.713 ± 0.137 mg/kg dw) gosling groups (average ± standard deviation). Upon immune challenge with double-stranded RNA (dsRNA) injection, endpoints for immune responses and oxidative stress were measured after 24 h. Our results indicated that Hg exposure modulated the immune responses in Arctic barnacle goslings upon a viral-like immune challenge. Increased exposure to both environmental as well as supplemental Hg reduced the level of natural antibodies, suggesting impaired humoral immunity. Hg exposure upregulated the expression of proinflammatory genes in the spleen, including inducible nitric oxide synthase (iNOS) and interleukin 18 (IL18), suggesting Hg-induced inflammatory effects. Exposure to Hg also oxidized glutathione (GSH) to glutathione disulfide (GSSG); however, goslings were capable of maintaining the redox balance by de novo synthesis of GSH. These adverse effects on the immune responses indicated that even exposure to low, environmentally relevant levels of Hg might affect immune competence at the individual level and might even increase the susceptibility of the population to infections.

Original languageEnglish
Pages (from-to)5337-5348
JournalEnvironmental Science and Technology
Volume57
Issue number13
DOIs
Publication statusPublished - 4 Apr 2023

Keywords

  • arctic
  • avian
  • barnacle goose (Branta leucopsis)
  • exposure and effect
  • immune toxicity
  • mercury

Fingerprint

Dive into the research topics of 'Mercury-Modulated Immune Responses in Arctic Barnacle Goslings (Branta leucopsis) upon a Viral-Like Immune Challenge'. Together they form a unique fingerprint.

Cite this