Serotonin modulates insect hemocyte phagocytosis via two different serotonin receptors
Serotonin modulates insect hemocyte phagocytosis via two different serotonin receptors
复制标题
血清素通过两种不同的血清素受体调节昆虫血细胞的吞噬作用。
DOI：
10.7554/elife.12241
复制
发表时间：
2016-03-14
期刊：
影响因子：
7.7
通讯作者：
Ye, Gong-yin
中科院分区：
文献类型：
--
作者：
Qi, Yi-xiang;Huang, Jia;Ye, Gong-yin
5-羟色胺（5-HT）调节脊椎动物的神经和免疫反应，但其在昆虫免疫中的作用尚不清楚。我们报告，在毛虫，粉蝶血细胞能够合成5-羟色胺激活后，脂多糖。通过药理学阻断或RNAi敲低来抑制一种降钙素生成酶会损害血细胞的吞噬作用。生化和功能实验表明，幼稚血细胞主要表达5-HT 1B和5-HT 2B受体。阻断5-HT 1B可显著降低吞噬能力;然而，阻断5-HT 2B可增加血细胞的吞噬作用。5-HT 1B-null果蝇突变体显示出更高的死亡率比对照组感染细菌时，由于其吞噬能力下降。在血细胞中表达5-HT 1B或5-HT 2B RNAi的果蝇也表现出类似的感染敏感性。综合起来，这些数据表明，5-HT介导的血细胞吞噬作用，通过5-HT 1B和5-HT 2B受体和β-羟色胺能信号传导执行关键的调节功能，在动物的免疫系统中分离的5亿年的进化。
Serotonin (5-HT) modulates both neural and immune responses in vertebrates, but its role in insect immunity remains uncertain. We report that hemocytes in the caterpillar, Pieris rapae are able to synthesize 5-HT following activation by lipopolysaccharide. The inhibition of a serotonin-generating enzyme with either pharmacological blockade or RNAi knock-down impaired hemocyte phagocytosis. Biochemical and functional experiments showed that naive hemocytes primarily express 5-HT1B and 5-HT2B receptors. The blockade of 5-HT1B significantly reduced phagocytic ability; however, the blockade of 5-HT2B increased hemocyte phagocytosis. The 5-HT1B-null Drosophila melanogaster mutants showed higher mortality than controls when infected with bacteria, due to their decreased phagocytotic ability. Flies expressing 5-HT1B or 5-HT2B RNAi in hemocytes also showed similar sensitivity to infection. Combined, these data demonstrate that 5-HT mediates hemocyte phagocytosis through 5-HT1B and 5-HT2B receptors and serotonergic signaling performs critical modulatory functions in immune systems of animals separated by 500 million years of evolution.