Ecdysone Titer Determined by 3DE-3β-Reductase Enhances the Immune Response in the Silkworm
Ecdysone Titer Determined by 3DE-3β-Reductase Enhances the Immune Response in the Silkworm
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3DE-3β-还原酶测定的蜕皮激素滴度可增强家蚕的免疫反应
DOI：
10.4049/jimmunol.1500158
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发表时间：
2016-02-15
影响因子：
4.4
通讯作者：
Zhang, Ze
中科院分区：
文献类型：
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作者：
Sun, Wei;Shen, Yi-Hong;Zhang, Ze
虽然最近的研究表明，20-羟基蜕皮激素（20-hydroxyecdysone, 20E）作为两种最重要的发育激素之一，可以促进昆虫的先天免疫反应，但昆虫在受到病原体攻击后如何调节20E滴度来影响免疫仍是未知的。在本研究中，据我们所知，我们首先发现家蚕（Bombyx mori）感染细菌后，20E滴度显著升高。此外，升高的20E通过脱皮激素受体增强家蚕先天免疫系统对入侵细菌的抵抗力。在免疫应答过程中，诱导家蚕3-脱氢蜕皮激素-3 β -还原酶（3DE-3 β -还原酶）的表达，将前胸腺释放的3DE转化为蜕皮激素。RNA干扰实验表明，细菌感染后，3DE-3 β -还原酶对上调20E滴度至关重要。救援实验表明，注射重组3DE-3 β还原酶蛋白可显著提高家蚕免疫相关基因的20E浓度，调节其表达。综上所述，3DE-3 β还原酶测定的20E滴度增强了家蚕对细菌感染的防御能力。因此，我们的研究结果揭示了3DE合成20E途径在增强家蚕免疫应答中的重要作用，对了解昆虫激素与免疫的相互作用机制具有深远的意义。
Although recent studies have demonstrated that 20-hydroxyecdysone (20E), one of the two most important hormones for development, could promote the insect innate immune response, how insects regulate 20E titer to affect the immunity after suffering pathogen attack remains unknown. In this study, to our knowledge, we first found that 20E titer was significantly elevated after bacterial infection in the domesticated silkworm, Bombyx mori. Furthermore, the elevated 20E enhanced the silkworm innate immune system against invading bacteria via ecdysone receptor. During immune response, the expression of the silkworm 3-dehydroecdysone-3 beta-reductase (3DE-3 beta-reductase) that converts 3DE released from prothoracic glands into ecdysone was induced. RNA interference experiments suggested that 3DE-3 beta-reductase is essential to upregulate the 20E titer after bacterial infection. The rescue experiments showed that injection with the recombinant 3DE-3 beta-reductase protein can significantly elevate the 20E concentration and modulate the expressions of the silkworm immune-related genes. Taken together, 20E titer determined by 3DE-3 beta-reductase enhances the silkworm defense against the bacterial infection. Thus, our findings reveal an important role of the 20E synthesis pathway from 3DE in enhancing the silkworm immune response and have profound implications for the understanding of interaction mechanisms between insect hormone and immunity.