高浓度的氨氮会抑制水生动物的免疫防御。对氨氮胁迫下的神经内分泌免疫(NEI)调控机制进行了系统的研究,但氨氮影响免疫系统的最终反应机制仍不清楚。探讨凡纳滨对虾(L.凡纳滨)暴露于0、2、10和20mg/L氨氮,补体成分的测定,C型凝集素,proPO系统,进行了信号转导途径和吞噬作用以及胞吐作用。结果表明,补体成分包括C1q,MBL,氨氮处理组的ficolin和α-2巨球蛋白(A2M)和补体受体整合素在6、12和24h显着降低。C型凝集素和信号转导因子显着变化。吞噬相关基因和吞噬活性的下降与补体成分的变化相似,C型凝集素与信号通路。在氨氮暴露下,胞吐相关基因的mRNA丰度显着下调。相应地,PPAE和PPO3,免疫因子相关基因的表达发生了显着变化(Pen3,crustin,stylicins,ALFs和LYC)和炎症因子(HSP90,TNFα,白细胞中的IL-16)。最终,丝氨酸蛋白酶活性,PO活动,血浆中的抗菌活性和溶菌活性显着降低。此外,我们推测在氨氮胁迫下,吞噬作用和胞吐作用受补体成分的影响,和C型凝集素通过细胞内信号转导途径。补体成分可能参与调节proPO激活系统以响应氨氮胁迫。本研究有助于进一步了解甲壳类动物响应环境胁迫的免疫因子之间的关系。这意味着当涉及到受环境压力影响的免疫力下降时,我们不应该只关注上游神经内分泌反应的机制,还要注意免疫因子的作用。
High concentration of ammonia-N will inhibit the immune defense of aquatic animals. The neuroendocrine-immune (NEI) regulatory mechanism under ammonia-N stress has been systematically studied, but the final response mechanism of ammonia-N affecting the immune system remains unclear. To investigate the relationship among immune factors of Litopenaeus vannamei (L. vannamei) exposed to 0, 2, 10 and 20 mg/L ammonia-N, the determination of complement components, C-type lectins, proPO system, signal transduction pathway and phagocytosis as well as exocytosis were performed. The results showed that the expressions of complement components including C1q, MBL, ficolin and alpha-2 macroglobulin (A2M) and the complement receptor integrin were decreased significantly in ammonia-N treatment groups at 6,12 and 24 h. C-type lectins and signal transduction factors changed significantly. The decrease of phagocytosis-related genes and phagocytic activity were similar to the changes of complement components, C-type lectins and the signal pathway. The mRNA abundance of exocytosis-related genes was significantly down-regulated under ammonia-N exposure. Correspondingly, significantly changes occurred in the expressions of PPAE and PPO3, immune factors-related genes (Pen3, crustin, stylicins, ALFs and LYC) and inflammatory factors (HSP90, TNFα, IL-16) in haemocytes. Eventually, the serine proteinase activity, PO activity, antibacterial activity and bacteriolytic activity in plasma were decreased significantly. In addition, we speculated that under ammonia-N stress, phagocytosis and exocytosis were affected by complement components, and C-type lectins through intracellular signal transduction pathway. Complement components may involve in the regulation of proPO-activating system to response to ammonia-N stress. This study helped to further understanding the relationship among immune factors of crustacean in response to environmental stress, which implied that when it comes to the decrease of immunity affected by environmental stress, we should not only focus on the mechanism of upstream neuroendocrine response, but also pay attention to the role of immune factors.