Li Meng, Li Caiwen, Wang Jinfeng, Song Shuqun
Key Lab of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Key Lab of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
Mol Immunol. 2015 May;65(1):113-22. doi: 10.1016/j.molimm.2015.01.002. Epub 2015 Feb 4.
The parasitic dinoflagellates in the genus of Hematodinium infect broad range of crustaceans around the world, causing fatal diseases in multiple species of wild and cultured crabs and subsequent economic loss. In order to explore this host-parasite interaction in the early development stage of infection, mRNA transcript levels of eight key immune-related genes, including LGBP, proPO, PPAF, serpin, α2m, and three PTcSPs were quantitatively assessed in Portunus trituberculatus artificially inoculated with the Hematodinium parasites. The fluctuation of proPO gene expression indicated that the host proPO system was disturbed overtly due to the intrusion of the parasites. And as manifested by the suppressed expression of LGBP and PPAF, an immunosuppressive mechanism was likely induced by the parasites against being entrapped or killed by the host proPO system. Furthermore, the significant variations of the transcript levels of serpin, α2m, and the three PTcSPs suggested that the parasites affected the proteinase cascade reactions associated with the immune response by destroying the balance between serine proteinases and the proteinase inhibitors. The hemocytes counts and PO activity varied accordingly over the time course of infection, showing that hemocytes were actively involved in the immune response against the parasitic invasion. This study primarily highlighted the anti-parasitic immune response of crab hosts, and presented the first report of the immune response of P. trituberculatus to the parasitic dinoflagellate Hematodinium.
血卵涡鞭虫属的寄生性甲藻感染世界各地的多种甲壳类动物，在多种野生和养殖蟹类中引发致命疾病，进而造成经济损失。为了探究感染早期阶段的这种宿主 - 寄生虫相互作用，对人工接种血卵涡鞭虫寄生虫的三疣梭子蟹中八个关键免疫相关基因的mRNA转录水平进行了定量评估，这些基因包括LGBP、proPO、PPAF、丝氨酸蛋白酶抑制剂、α2m以及三个PTcSPs。proPO基因表达的波动表明，由于寄生虫的侵入，宿主的proPO系统受到明显干扰。而LGBP和PPAF表达的抑制表明，寄生虫可能诱导了一种免疫抑制机制，以防止被宿主proPO系统捕获或杀死。此外，丝氨酸蛋白酶抑制剂、α2m以及三个PTcSPs转录水平的显著变化表明，寄生虫通过破坏丝氨酸蛋白酶和蛋白酶抑制剂之间的平衡，影响了与免疫反应相关的蛋白酶级联反应。在感染过程中，血细胞计数和PO活性随时间相应变化，表明血细胞积极参与了针对寄生虫入侵的免疫反应。本研究主要突出了蟹宿主的抗寄生虫免疫反应，并首次报道了三疣梭子蟹对寄生性甲藻血卵涡鞭虫的免疫反应。
