Suppr超能文献

通过小型化吞噬试验评估双壳贝类血细胞的免疫能力。

Immunocompetence of bivalve hemocytes as evaluated by a miniaturized phagocytosis assay.

作者信息

Blaise C, Trottier S, Gagné F, Lallement C, Hansen P-D

机构信息

St. Lawrence Centre, Environment Canada, 105 McGill Street, Montreal, Quebec, Canada H2Y 2E7.

出版信息

Environ Toxicol. 2002;17(3):160-9. doi: 10.1002/tox.10047.

Abstract

Immune function in bivalves can be adversely affected by long-term exposure to environmental contaminants. Investigating alterations in immunity can therefore yield relevant information about the relationship between exposure to environmental contaminants and susceptibility to infectious diseases. We have developed a rapid, cost-effective, and miniaturized immunocompetence assay to evaluate the phagocytic activity, viability, and concentration of hemocytes in freshwater and marine bivalves. Preliminary experiments were performed to optimize various aspects of the assay including 1) the time required for adherence of hemocytes to polystyrene microplate wells, 2) the time required for internalization of fluorescent bacteria, 3) the ratio of hemocytes to fluorescent bacteria in relation to phagocytosis, 4) hemolymph plasma requirements, and 5) the elimination of fluorescence from (noninternalized) bacteria adhering to the external surface of hemocytes. The results of these experiments showed the optimal adherence time for hemocytes in microplate wells to be 1 h, that phagocytosis required at least 2 h of contact with fluorescently labeled E. coli cells, that the number of fluorescent E. coli cells had a positive effect on phagocytic activity, that at least 2.5 million cells/mL were required to measure a significant intake, and that a linear increase in uptake of bacteria (R = 0.91; p < 0.01) could be obtained with concentrations of up to 1.3 x 10(6) hemocytes/mL. Afterward, the assay was used in two field studies to identify sites having the potential to affect the immunocompetence of bivalves. The first study was conducted on Mya arenaria clams collected at selected contaminated sites in the Saguenay River (Quebec, Canada), and the second examined Elliptio complanata freshwater bivalves that had been exposed to a municipal effluent plume in the St. Lawrence River (Quebec, Canada). In the Saguenay River field study a significant increase in phagocytosis was observed at sites closest to polluted areas. Phagocytotic activity varied over time and was highest during the warmest months (June, July, and August), closely paralleling the spawning period of Mya arenaria clams. In contrast, a drop in phagocytic activity was observed in Elliptio complanata mussels exposed to surface water 4 km downstream of a major municipal effluent plume, with a concomitant increase in the number of hemocytes in the hemolymph. It appears that both immunosuppressive and immunostimulative effects are likely to occur in the field and that responses will be influenced by the type and intensity of contaminants at play.

摘要

双壳贝类的免疫功能可能会因长期暴露于环境污染物而受到不利影响。因此,研究免疫功能的变化可以获得有关环境污染物暴露与传染病易感性之间关系的相关信息。我们开发了一种快速、经济高效且小型化的免疫能力检测方法,用于评估淡水和海洋双壳贝类血细胞的吞噬活性、活力和浓度。进行了初步实验以优化该检测方法的各个方面,包括:1)血细胞附着于聚苯乙烯微孔板孔所需的时间;2)荧光细菌内化所需的时间;3)与吞噬作用相关的血细胞与荧光细菌的比例;4)血淋巴血浆的需求量;5)消除附着在血细胞外表面的(未内化)细菌的荧光。这些实验结果表明,血细胞在微孔板孔中的最佳附着时间为1小时,吞噬作用需要与荧光标记的大肠杆菌细胞至少接触2小时,荧光大肠杆菌细胞的数量对吞噬活性有积极影响,测量到显著摄取量至少需要250万个细胞/毫升,并且血细胞浓度高达1.3×10⁶个/毫升时,细菌摄取量呈线性增加(R = 0.91;p < 0.01)。此后,该检测方法被用于两项实地研究,以确定有可能影响双壳贝类免疫能力的地点。第一项研究针对在加拿大魁北克省萨格奈河选定污染地点采集的砂海螂蛤进行,第二项研究则检测了在加拿大魁北克省圣劳伦斯河受城市污水羽流影响的椭圆蚌淡水双壳贝类。在萨格奈河实地研究中,在最靠近污染区域的地点观察到吞噬作用显著增加。吞噬活性随时间变化,在最温暖的月份(6月、7月和8月)最高,与砂海螂蛤的产卵期密切平行。相比之下,在主要城市污水羽流下游4公里处暴露于地表水的椭圆蚌贻贝中观察到吞噬活性下降,同时血淋巴中血细胞数量增加。看来在实地可能会同时出现免疫抑制和免疫刺激作用,并且反应将受到所涉及污染物的类型和强度的影响。

文献AI研究员

20分钟写一篇综述,助力文献阅读效率提升50倍。

立即体验

用中文搜PubMed

大模型驱动的PubMed中文搜索引擎

马上搜索

文档翻译

学术文献翻译模型,支持多种主流文档格式。

立即体验