Decreased Lymphocyte Responses in Free-Ranging Bottlenose Dolphins (Tursiops truncatus) Are Associated with Increased Concentrations of PCBs and DDT in Peripheral Blood

Lahvis, Garet P.; Wells, Randall S.; Kuehl, Douglas W.; Stewart, Jennifer L.; Rhinehart, Howard L.; Via, Charles S.

doi:10.2307/3432414

Cited by 88 publications

(93 citation statements)

References 30 publications

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“…Previous investigations of contaminant-induced immune suppression in marine mammals have typically correlated impaired immune responses or less specific biomarkers with tissue levels of polyhalogenated aromatic hydrocarbons (PHAHs) such as the organochlorine pesticides and PCBs (Reijnders, 1994;Lahvis et al, 1995;Simms et al, 2000). While providing circumstantial evidence for immune suppression, causal relationships and mechanisms of action could not be established.…”

Section: Discussionmentioning

confidence: 92%

Proliferative Responses of Harbor Seal (Phoca vitulina) T Lymphocytes to Model Marine Pollutants

Neale

Water²,

Harvey

et al. 2002

Journal of Immunology Research

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In recent years, population declines related to viral outbreaks in marine mammals have been associated with polluted coastal waters and high tissue concentrations of certain persistent, lipophilic contaminants. Such observations suggest a contributing role of contaminant-induced suppression of cell-mediated immunity leading to decreased host resistance. Here, we assessed the effects of the prototypic polycyclic aromatic hydrocarbon (PAH), benzo [a]pyrene (B[a]P), and two polychlorinated biphenyls (PCBs), CB-156 and CB-80, on the T-cell proliferative response to mitogen in harbor seal peripheral lymphocytes. Despite the variability associated with our samples from free-ranging harbor seals, we observed a clear suppressive effect of B[a]P (10 uM) exposure on T cell mitogenesis. Exposures to 10 uM CB-156 and CB-80, and 1.0 and 0.1 uM B[a]P, did not produce significant depression in lymphoproliferation. Exposure to the model PAH at 10 uM resulted in a 61% (range 34 -97%) average reduction in lymphoproliferation. We were able to rule out a direct cytotoxic effect of B[a]P, indicating that observed effects were due to altered T cell function. Based on our in vitro results, we hypothesize that extensive accumulation of PAH by top-trophic-level marine mammals could alter T cell activation in vivo and impaired cell-mediated immunity against viral pathogens.Keywords: Benzo[a]pyrene; Harbor seal; Immunotoxicity; Lymphoproliferation; PAH; PCB INTRODUCTIONUnderstanding immune alterations related to environmental contamination has become an important priority in marine mammal research because of the high incidence in recent years of mass mortality events, unexplained population declines, and strandings among marine mammal populations (Dietz et al., 1989; Marine Mammal Commission, 1999;Kennedy et al., 2000). These events have been largely attributed to disease outbreaks caused by established or newly identified members of the genus Morbillivirus (Geraci et al., 1982;Osterhaus and Vedder, 1988;Duignan et al., 1995). Common features of these massive die-offs include highly polluted habitat and high tissue concentrations in affected individuals of persistent, lipophilic contaminants, including those known to have deleterious effects on the immune systems of rodents and humans (Hall et al., 1992;Visser et al., 1993;Reijnders, 1994). Whereas contaminant-induced immune suppression has been suggested as a major contributing factor in marine mammal disease epizootics, causal relationships and potential mechanisms of immunotoxicity have not been established (Olsson et al., 1994; Marine Mammal Commission, 1999;van Loveren et al., 2000).The harbor seal (Phoca vitulina) is an ideal model organism for investigating contaminant-induced immune alterations in marine mammals. Fish-eating seals are longlived, maintain large adipose deposits, and occupy high trophic levels in the marine food chain, thus accumulating relatively high levels of lipophilic contaminants (Boon et al., 1987;Young et al., 1998; Neale, unpublished data). Among marine m...

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Section: Discussionmentioning

confidence: 92%

Proliferative Responses of Harbor Seal (Phoca vitulina) T Lymphocytes to Model Marine Pollutants

Neale

Water²,

Harvey

et al. 2002

Journal of Immunology Research

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“…All contaminant values are given as wet weights unless asterisked. Sources: Peneda et al (1980), Adams & Martin (1986), Geraci (1989), Kirby-Smith & Costlow (1989), Morris et al (1989), Jones & Je¡s (1991), Law et al (1991), Leonzio et al (1992), Kuehl et al (1994), Levitus et al (1994), World Health Organization (1994), Corsolini et al (1995), Kuehl & Haebler (1995), Salata et al (1995), Wood & Van Vleet (1996), Kannan et al (1997), McKenzie et al (1997) each population are a¡ected. Furthermore, because only the dorsal ¢ns of the dolphins were examined, and lesions were observed on other parts of the dolphins when they could be photographed, the total levels of prevalence are likely to be higher still.…”

Section: Discussionmentioning

confidence: 99%

“…Recent mass mortalities have highlighted the potential role of contaminants in disease susceptibility (Hall et al 1992;Aguilar & Borrell 1994) and, in controlled experimental conditions, organochlorines and heavy metals have been demonstrated to adversely a¡ect immune function (Swart et al 1994). However, with few exceptions (Lahvis et al 1995), most studies in the ¢eld have focused on recording tissue contaminant levels, but the actual consequences of these burdens on the health of their host populations remain unclear. Information from captive studies and other wild populations or species may be used to make inferences about the impacts of particular contaminant levels on a speci¢c population.…”

Section: Introductionmentioning

confidence: 99%

Epidermal diseases in bottlenose dolphins: impacts of natural and anthropogenic factors

Wilson

Arnold

Bearzi

et al. 1999

Proc. R. Soc. Lond. B

110

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Experimental studies have highlighted the potential in£uence of contaminants on marine mammal immune function and anthropogenic contaminants are commonly believed to in£uence the development of diseases observed in the wild. However, estimates of the impact of contaminants on wild populations are constrained by uncertainty over natural variation in disease patterns under di¡erent environmental conditions. We used photographic techniques to compare levels of epidermal disease in ten coastal populations of bottlenose dolphins (Tursiops truncatus) exposed to a wide range of natural and anthropogenic conditions. Epidermal lesions were common in all populations (a¡ecting 460% of individuals), but both the prevalence and severity of 15 lesion categories varied between populations. No relationships were found between epidermal disease and contaminant levels across the four populations for which toxicological data were available. In contrast, there were highly signi¢cant linear relationships with oceanographic variables. In particular, populations from areas of low water temperature and low salinity exhibited higher lesion prevalence and severity. Such conditions may impact on epidermal integrity or produce more general physiological stress, potentially making animals more vulnerable to natural infections or anthropogenic factors. These results show that variations in natural environmental factors must be accounted for when investigating the importance of anthropogenic impacts on disease in wild marine mammals.

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“…Subsequent laboratory studies showed that HAHs increased susceptibility to bacteria (42,48,61), viruses (26,50,62), and protozoan parasites (26). Several investigators suggested associations between epizootics and elevated organochlorine exposure in beluga whales (Delphinapterus leucas) in the St. Lawrence Estuary (63), California sea lions (Zalophus californianus) on San Miguel Island (64,65), harbor seals (Phoca vitulina) in Europe (66)(67)(68), and bottlenose dolphins (Tursiops truncatus) in the Atlantic Ocean (69). At highly contaminated sites in the Great Lakes, doublecrested cormorants (Phalacrocorax auritus) had increased rates of eye infections associated with Pasteurella multocida (70).…”

Section: Introductionmentioning

confidence: 99%

Organochlorine-Associated Immunosuppression in Prefledgling Caspian Terns and Herring Gulls from the Great Lakes: An Ecoepidemiological Study

Grasman¹,

Fox²,

Scanlon³

et al. 1996

Environmental Health Perspectives

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The objectives of this study were to determine whether contaminant-associated immunosuppression occurs in prefledgling herring gulls and Caspian terns from the Great Lakes and to evaluate immunological biomarkers for monitoring health effects in wild birds. During 1992 to 1994, immunological responses and related variables were measured in prefledgling chicks at colonies distributed across a broad gradient of organochlorine contamination (primarily polychlorinated biphenyls), which was measured in eggs. The phytohemagglutinin skin test was used to assess T-lymphocyte function. In both species, there was a strong exposure-response relationship between organochlorines and suppressed T-cell-mediated immunity. Suppression was most severe (30-45%) in colonies in Lake Ontario (1992) and Saginaw Bay (1992)(1993)(1994) for both species and in western Lake Erie (1992) for herring gulls. Both species exhibited biologically significant differences among sites in anti-sheep red blood cells antibody titers, but consistent exposure-response relationships with organochlorines were not observed. In Caspian terns and, to a lesser degree, in herring gulls, there was an exposure-response relationship between organochlorines and reduced plasma retinol (vitamin A). In 1992, altered white blood cell numbers were associated with elevated organochlorine concentrations in Caspian terns but not herring gulls. The immunological and hematological biomarkers used in this study revealed contaminantassociated health effects in wild birds. An epidemiological analysis strongly supported the hypothesis that suppression of T-cell-mediated immunity was associated with high perinatal exposure to persistent organochlorine contaminants.Environ Health Perspect 104(Suppl 4): 829-842 (1996)

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Decreased Lymphocyte Responses in Free-Ranging Bottlenose Dolphins (Tursiops truncatus) Are Associated with Increased Concentrations of PCBs and DDT in Peripheral Blood

Cited by 88 publications

References 30 publications

Proliferative Responses of Harbor Seal (Phoca vitulina) T Lymphocytes to Model Marine Pollutants

Proliferative Responses of Harbor Seal (Phoca vitulina) T Lymphocytes to Model Marine Pollutants

Epidermal diseases in bottlenose dolphins: impacts of natural and anthropogenic factors

Organochlorine-Associated Immunosuppression in Prefledgling Caspian Terns and Herring Gulls from the Great Lakes: An Ecoepidemiological Study

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