Impairment of Cellular Immunity in West Greenland Sledge Dogs (Canis familiaris) Dietary Exposed to Polluted Minke Whale (Balaenoptera acutorostrata) Blubber

Abstract

Minke whale (Balaenoptera acutorostrata) blubber is rich in organohalogen contaminants, mercury, and n-3 fatty acids. In the present study we show that a daily intake of 50-200 g of minke whale blubber causes an impairment of the nonspecific and specific cellular immune system in the West Greenland sledge dog (Canis familiaris). Immune reactions were measured by mitogen (PHA, Con A) and antigen (KLH) intradermal testing, and as the study used exposure levels similar to those of Inuits and polar bears (Ursus maritimus), it is reasonable to infer that Inuits and polar bears suffer from similar decreased resistance to diseases. It is speculated that food sources are depleted by thinning sea ice due to climate change and that more research should assess the forecasted rise in additive immunopathy effects in polar bears. Additionally, our study suggests that the fatty acid composition may be of importance when investigating combined immunotoxic effects of contaminated food resources in future Inuit and polar bear studies.

High Accumulation of Perfluorooctane Sulfonate (PFOS) in Marine Tucuxi Dolphins (Sotalia guianensis) from the Brazilian Coast

“…The immunosuppressive action has been also demonstrated regarding other pollutants of environmental concern, such as cadmium (51), organotins (52), and organochlorines (53). Some investigations have demonstrated that cadmium does not seem to constitute a problem for coastal cetaceans in Brazil (54)(55)(56); however, the same could not be stated about organotins (42) and organochlorines (57).…”

High accumulation of PCDD, PCDF, and PCB congeners in marine mammals from Brazil: A serious PCB problem

“…The sample set analyzed by Kuehl et al (1991) included bottlenose dolphins obtained after an unusual mortality event. Although the impact of these immunosuppressive compounds (Sonne et al, 2006a) is not fully known, their role as causative agents in that mass mortality was considered by the authors (Kuehl et al, 1991), which emphasizes the toxicological importance of the concentrations found in Guiana dolphins from RJ. Among cetaceans species, the highest concentrations of biomagnifying pollutants are usually found in killer whales, due to their predation on organisms that occupy high trophic positions, such as sharks, seals and other cetaceans (O'Shea and Tanabe, 2003).…”

“…Environmental contamination by DRCs constitutes one additional obstacle for these marine mammals to reach their natural longevity and reproduce at a physiologically normal rate. The concerns generated by the DRC contamination are amplified when it is taken into account that these cetaceans are exposed to other persistent bioaccumulative toxicants (PBTs) that have been shown to be endocrine disrupters, tumor promoters and immunosuppressors as well (Schecter et al, 2006;Simonyte et al, 2006;Sonne et al, 2006a;Whalen et al, 1999). The high exposure of cetaceans from Brazil to cadmium (Dorneles et al, 2007a(Dorneles et al, , 2007b, mercury (Lailson-Brito et al, 2012a), organochlorine pesticides (Lailson-Brito et al, 2011, 2010, 2012b, as well as to organotin (Dorneles et al, 2008b), perfluoroalkyl (Dorneles et al, 2008a) and organobrominated (Alonso et al, 2012;Dorneles et al, 2010) compounds has already been reported.…”

Correlation between maternal milk and infant serum levels of chlorinated pesticides (CP) and the impact of elevated CP on bleeding tendency and immune status in some infants in Egypt

“…These results suggest that the negative association observed between some OC and TNFα secretion by activated cord blood mononuclear cells (CBMC) could be caused by dioxin-like PCB congeners (Devos et al, 2004). Furthermore, O'Neill (2002) suggested that binding of dioxin-like compounds to the aryl hydrocarbon receptor (a transcription factor) can antagonize the effects of another transcription factor, nuclear factor (NF)-κB, an important regulator of immune and inflammatory gene expression (Sonne et al, 2006). Bilrha et al (2003) found that newborns exposed to OC in utero had significantly decreased TNFα production, suggesting that these children may be more susceptible to infection.…”

“…In vitro studies by Kidd (2003) and by Mills (2004) using cultured lymph node cells showed that exposure to PCBs led to increased IL-4 and IL-6 expression, whereas IL-1, IL-2, and IFNγ expression were decreased, supporting an immunomodulating effect on the T H 1/T H 2 balance (naive CD4 + CD8 + T-cells) and indicating a shift toward T H 2 immune response (and thus, potential immunosuppression). Moreover, Sonne et al (2006) reported impairment of T-cell-mediated cellular immunity (as measured by intradermal testing) in West Greenland sledge dogs after dietary exposure to OHC-polluted Minke whale blubber for up to 52 weeks. Similar intradermal studies of guinea pigs fed a 50-ppm PCB diet, and of rabbits fed DDT and Aroclor 1254 (at 150 ppm), indicated significantly decreased cell-mediated immunity (Sonne et al, 2006).…”