The Enhanced Immune Protection in Chinese Mitten Crab Eriocheir sinensis Against the Second Exposure to Bacteria Aeromonas hydrophila
The Enhanced Immune Protection in Chinese Mitten Crab Eriocheir sinensis Against the Second Exposure to Bacteria Aeromonas hydrophila
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中华绒螯蟹对嗜水气单胞菌二次暴露的增强免疫保护
DOI：
10.3389/fimmu.2019.02041
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发表时间：
2019-08-28
影响因子：
7.3
通讯作者：
Song, Linsheng
中科院分区：
文献类型：
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作者：
Wang, Jingjing;Yang, Bin;Song, Linsheng
越来越多的证据表明，初次接触包括商业价值甲壳类动物在内的各种生物中的各种微生物群落及其成分后，免疫反应和对细菌引起的死亡的保护能力就会增强。本研究采用福尔马林灭活的嗜水气单胞菌免疫启动（IP）和嗜水气单胞菌免疫攻击（ICH）两组对中华绒螯蟹的存活率和免疫应答进行了研究。另设攻毒前给盐注射组作为对照组（Ns组）。本研究结果表明，嗜水拟合单胞杆菌灭活IP能显著保护大闸蟹免受ICH致死剂量的感染。生存期的增加与吞噬率和持续时间的增加有关。Ah组血清抗菌活性显著高于Ns组。酚氧化酶（PO）活性在Ah组和Ns组之间有显著变化，而在Ah组和ICH之间无显著变化。除注射后3 h外，Ah组和NS组溶菌酶在整个实验期间均无明显变化。此外，Ah组的蟹血细胞中Dscam转录本和蛋白水平均有所升高。这些结果表明，当螃蟹第二次遭遇同一种活病原体时，用一种特定的灭活病原体进行一次免疫启动，可诱导其免疫增强。螃蟹免疫保护作用增强的证据将有助于更好地理解无脊椎动物免疫启动的机制。
Accumulating evidences suggest that the enhanced immune responses and increased protection against bacteria-induced mortality can be initiated after the primary exposure to various microbial communities and their components in various organisms including commercially valuable crustaceans. In the present study, the survival rate and immune responses of Chinese mitten crab Eriocheir sinensis were determined after an immune priming (IP) with formalin-killed Aeromonas hydrophila and an immune challenge (ICH) with the same but live pathogen (Ah group). A group in which the animals received a salt injection prior to challenge was maintained as control (Ns group). In the present study, it was shown that an IP with killed A. hydrophila can significantly protect the crabs against the ICH with a lethal dose of the live pathogen. The increased survival was associated with elevated rate and duration of phagocytosis. The antibacterial activity of the serum was significantly increased in Ah group compared to that in Ns group. Significant changes of phenoloxidase (PO) activities were also found between Ah and Ns group but not in Ah group between IP and ICH. No significant changes of lysozyme were found in Ah and NS group during the whole experiment except 3 h after IP. In addition, the levels of transcripts and protein of Dscam were increased in hemocytes of the crabs from Ah group. All the results suggested that a primary immune priming with a particular killed pathogen could induce an enhanced immunity in crabs when they were encountered secondly with the same live pathogen. The evidences of elevated immune protections in crabs would contribute to better understand the mechanism of immune priming in invertebrates.