Levin Milton, De Guise Sylvain, Ross Peter S
Department of Pathobiology and Veterinary Science, University of Connecticut, 61 North Eagleville Road, U-89, Storrs, Connecticut 06269, USA.
Environ Toxicol Chem. 2005 May;24(5):1247-52. doi: 10.1897/04-206r.1.
Recent pinniped die-offs have led to the speculation that persistent organic pollutants (POPs) are immunomodulatory, making individuals more susceptible to viral infections. Eighteen healthy harbor seal (Phoca vitulina) pups (aged 3-4 weeks) were live-captured from southern British Columbia, Canada, and maintained temporarily in captivity for an immunotoxicological assessment. The relationships between mitogen-induced peripheral blood lymphocyte proliferation and blubber concentrations of three major immunotoxic POP classes (the polychlorinated biphenyls [PCBs], polychlorinated dibenzo-p-dioxins [PCDDs], and the polychlorinated dibenzofurans [PCDFs]) were evaluated. A significant body weight-independent positive correlation was observed between both T-cell mitogen (phytohemagglutinin [PHA])- and B-cell mitogen (lipopolysaccharide [LPS])-induced lymphocyte proliferation and the blubber concentrations of total PCB. Best subset regression analysis revealed that total PCBs, and not total PCDD or total PCDF, explained 24 and 29% of the changes in both T-cell mitogen-and B-cell mitogen-induced lymphocyte proliferation, respectively. Further regression analysis performed on the PCB classes measured in this study showed that di-ortho PCBs accounted for 25 and 30% of the changes in both T-cell and B-cell lymphocyte proliferation, respectively. Results suggest that POPs, and PCBs in particular, are associated with changes in lymphocyte proliferation, something that could result in increased susceptibility to infections in harbor seal pups. Further research is needed to evaluate the relative roles of natural and contaminant-related influences on the immune system of marine mammals.
近期鳍足类动物的死亡事件引发了一种推测，即持久性有机污染物（POPs）具有免疫调节作用，会使个体更容易受到病毒感染。从加拿大不列颠哥伦比亚省南部活捉了18只健康的港海豹幼崽（3 - 4周龄），并将它们暂时圈养起来进行免疫毒理学评估。评估了有丝分裂原诱导的外周血淋巴细胞增殖与三种主要免疫毒性POP类别（多氯联苯[PCBs]、多氯二苯并对二恶英[PCDDs]和多氯二苯并呋喃[PCDFs]）的脂肪浓度之间的关系。在T细胞有丝分裂原（植物血凝素[PHA]）和B细胞有丝分裂原（脂多糖[LPS]）诱导的淋巴细胞增殖与总PCB的脂肪浓度之间均观察到了显著的与体重无关的正相关。最佳子集回归分析表明，总PCBs而非总PCDD或总PCDF分别解释了T细胞有丝分裂原和B细胞有丝分裂原诱导的淋巴细胞增殖变化的24%和29%。对本研究中测量的PCB类别进行的进一步回归分析表明，邻位PCB分别占T细胞和B细胞淋巴细胞增殖变化的25%和30%。结果表明，POPs，尤其是PCBs，与淋巴细胞增殖的变化有关，这可能导致港海豹幼崽对感染的易感性增加。需要进一步研究来评估自然因素和污染物相关因素对海洋哺乳动物免疫系统的相对作用。
