Many species of marine life in southwestern Florida, including sea turtles, are impacted by blooms of the toxic dinoflagellate, Karenia brevis. Sublethal exposure to toxins produced by K. brevis has been shown to impact sea turtle health. Since all sea turtles in the Gulf of Mexico have protected status, a freshwater turtle, Trachemys scripta, was used as a model for immune system effects following experimental exposure to a predominant brevetoxin congener in K. brevis blooms, PbTx-3. Exposure to PbTx-3 was oral or intratracheal and health effects were assessed using a suite of immune function parameters: innate immune function (phagocytosis, plasma lysozyme activity), adaptive immune function (lymphocyte proliferation), and measures of oxidative stress (superoxide dismutase (SOD) and glutathione-S-transferase (GST) activity in plasma). Inflammation was also measured using plasma protein electrophoresis. In addition, differential expression of genes in peripheral blood leukocytes was determined using suppression subtractive hybridization followed by real-time PCR of specific genes. The primary immune effects of sublethal brevetoxin exposure in T. scripta following PbTx-3 administration, appear to be an increase in oxidative stress, a decrease in lysozyme activity, and modulation of immune function through lymphocyte proliferation responses. Plasma protein electrophoresis showed a decreased A:G ratio which may indicate potential inflammation. Genes coding for oxidative stress, such as thioredoxin and GST, were upregulated in exposed animals. That sublethal brevetoxin exposures impact immune function components suggests potential health implications for sea turtles naturally exposed to toxins. Knowledge of physiological stressors induced by brevetoxins may contribute to the ultimate goal of developing directed treatment strategies in exposed animals for reduced mortality resulting from red tide toxin exposure in sea turtles.

中文翻译：

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暴露于主要的短毒素毒素同源物PbTx-3后，Tracyys scripta中的免疫功能可作为自然暴露于短毒素毒素的海龟对健康的潜在影响的模型。

佛罗里达州西南部的许多海洋生物物种，包括海龟，都受到有毒的鞭毛藻鞭毛（Karenia brevis）绽放的影响。亚致死性暴露于短毛克鲁维酵母产生的毒素会影响海龟的健康。由于墨西哥湾中的所有海龟都处于受保护的地位，因此，在实验性暴露于短K. brevis花朵中主要的短毒素同类物PbTx-3之后，使用了淡水龟Trachemys scripta作为免疫系统效应的模型。口服或气管内暴露于PbTx-3，并使用一系列免疫功能参数评估健康影响：先天免疫功能（吞噬作用，血浆溶菌酶活性），适应性免疫功能（淋巴细胞增殖）和氧化应激的测量值（超氧化物歧化酶（ SOD）和血浆中的谷胱甘肽-S-转移酶（GST）活性。还使用血浆蛋白电泳测量了炎症。另外，使用抑制性消减杂交，然后实时PCR特定基因，确定外周血白细胞中基因的差异表达。施用PbTx-3后，亚致死性短杆菌毒素暴露于T. scripta中的主要免疫作用似乎是氧化应激增加，溶菌酶活性降低以及通过淋巴细胞增殖反应调节免疫功能。血浆蛋白电泳显示A：G比降低，这可能表明潜在的炎症。编码氧化应激的基因，例如硫氧还蛋白和GST，在裸露的动物中上调。亚致死性短杆菌毒素暴露会影响免疫功能成分，这提示自然暴露于毒素的海龟对健康的潜在影响。由短毒素引起的生理应激源的知识可能有助于最终目标的发展，即在暴露的动物中开发定向治疗策略以降低因海龟赤潮毒素暴露而导致的死亡率。