Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
Fish Shellfish Immunol. 2013 Jan;34(1):100-8. doi: 10.1016/j.fsi.2012.10.011. Epub 2012 Oct 13.
Nitric oxide (NO) is an important signalling molecule which plays an indispensable role in immunity of all vertebrates and invertebrates. In the present study, the immunomodulation of inducible NO in scallop Chlamys farreri was examined by monitoring the alterations of haemocyte behaviours and related immune molecules in response to the stimulations of LPS and/or with S-Methylisothiourea Sulphate (SMT), an inhibitor of inducible NO synthase (NOS). The total activity of NOS and NO concentration in the haemolymph of scallop C. farreri increased significantly at 3, 6 and 12 h after LPS stimulation respectively, whereas their increases were fully repressed when scallops were treated in the collaborating of LPS and SMT. Meanwhile, some cellular and humoral immune parameters were determined after the stimulation of LPS and SMT to investigate the role of inducible NO in innate immunity of scallop. After LPS stimulation, the highest levels of haemocytes apoptosis and phagocytosis were observed at 24 h (38.5 ± 2.5%, P < 0.01) and 12 h (38.6 ± 0.2%, P < 0.01), respectively, and the reactive oxygen species (ROS) level (5.88 ± 0.90%, P < 0.01) of haemocytes and anti-bacterial activity of haemolymph (10.0 ± 2.2%, P < 0.01) all elevated dramatically at 12 h. Although the activity of lysozyme and phenoloxidase (PO) in haemolymph both declined at 48 h (93.0 ± 6.3 U mgprot(-1), 0.40 ± 0.06 U mgprot(-1), P < 0.01), superoxide dismutase (SOD) activity and GSH concentration both increased to the highest level at 24 h post treatment (99.2 ± 8.1 U mgprot(-1), 93.0 ± 6.3 nmol mgprot(-1), P < 0.01). After the collaborating treatment of LPS and SMT, the apoptosis index increased much higher from 48 h, while the increase of haemocytes phagocytosis, ROS level and haemolymph anti-bacteria activities were suppressed completely at 12 h. The declines of lysozyme and PO activity in haemolymph were reversed at 48 h, and the rise of SOD activity and GSH concentration started earlier from 3 h. These results indicated clearly that NO could participate in the scallop immunity and play a crucial role in the modulation of immune response including haemocytes apoptosis and phagocytosis, anti-bacterial activity and redox homeostasis in the haemolymph of scallop.
一氧化氮（NO）是一种重要的信号分子，在所有脊椎动物和无脊椎动物的免疫中发挥着不可或缺的作用。在本研究中，通过监测脂多糖（LPS）刺激和/或 S-甲基异硫脲硫酸盐（SMT）抑制诱导型一氧化氮合酶（NOS）后对血细胞行为和相关免疫分子的改变，研究了扇贝 Chlamys farreri 中诱导型 NO 的免疫调节作用。在 LPS 刺激后，扇贝 C. farreri 血淋巴中的 NOS 总活性和 NO 浓度分别在 3、6 和 12 h 时显著增加，而当扇贝在 LPS 和 SMT 的协同作用下处理时，它们的增加被完全抑制。同时，在 LPS 和 SMT 刺激后测定了一些细胞和体液免疫参数，以研究诱导型 NO 在扇贝先天免疫中的作用。在 LPS 刺激后，血细胞凋亡和吞噬作用的最高水平分别在 24 h（38.5 ± 2.5%，P < 0.01）和 12 h（38.6 ± 0.2%，P < 0.01）观察到，并且血细胞中的活性氧（ROS）水平（5.88 ± 0.90%，P < 0.01）和血淋巴中的抗细菌活性（10.0 ± 2.2%，P < 0.01）均在 12 h 时显著升高。尽管 48 h 时血淋巴中的溶菌酶和酚氧化酶（PO）活性均下降（93.0 ± 6.3 U mgprot-1，0.40 ± 0.06 U mgprot-1，P < 0.01），但超氧化物歧化酶（SOD）活性和 GSH 浓度在处理后 24 h 均升高至最高水平（99.2 ± 8.1 U mgprot-1，93.0 ± 6.3 nmol mgprot-1，P < 0.01）。在 LPS 和 SMT 的协同处理后，凋亡指数从 48 h 开始增加得更高，而 12 h 时血细胞吞噬作用、ROS 水平和血淋巴抗细菌活性的增加完全受到抑制。血淋巴中溶菌酶和 PO 活性的下降在 48 h 时得到逆转，SOD 活性和 GSH 浓度的上升从 3 h 开始。这些结果清楚地表明，NO 可以参与扇贝的免疫，并在调节包括血细胞凋亡和吞噬作用、抗细菌活性和血淋巴氧化还原平衡在内的免疫反应中发挥关键作用。
