BmMD‐2A responds to 20‐hydroxyecdysone and regulates Bombyx mori silkworm innate immunity in larva‐to‐pupa metamorphosis
BmMD‐2A responds to 20‐hydroxyecdysone and regulates Bombyx mori silkworm innate immunity in larva‐to‐pupa metamorphosis
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DOI：
10.1111/1744-7917.13097
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发表时间：
2022-07
期刊：
影响因子：
4
通讯作者：
Ruonan Zhang;Xue Chen;Yuan Wang;Xu Bai;Qiong Yang;Yangjin Zhong;Xiao-qiang Yu;F. Jin;Wanying Yang
中科院分区：
文献类型：
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作者：
Ruonan Zhang;Xue Chen;Yuan Wang;Xu Bai;Qiong Yang;Yangjin Zhong;Xiao-qiang Yu;F. Jin;Wanying Yang
20 E-羟基蜕皮激素（20 E）在昆虫幼虫蜕皮和变态中起重要作用，也参与昆虫先天免疫反应。昆虫变态是一种非常成功的环境适应策略，也是昆虫对各种病原体敏感的最脆弱阶段。20 E通过激活果蝇的免疫缺陷（IMD）途径调节一系列抗菌肽（AMP）;然而，20 E调节的昆虫免疫是否涉及其他免疫途径尚不清楚。我们之前的研究表明，BmMD-2A是MD-2相关脂质识别（ML）蛋白家族的成员，参与家蚕先天免疫Toll信号通路。在本研究中，我们进一步证明了BmMD-2A也受到20 E的正调控，BmMD-2A中和实验表明，20 E通过调控BmMD-2A在幼虫变态中激活了一些下游免疫效应因子，即针对大肠杆菌和金黄色葡萄球菌的AMP基因，这意味着B.家蚕在幼虫-蛹变态阶段可能通过Toll-ML信号通路来维持先天免疫平衡，这是与果蝇中IMD通路相比由20 E调节的不同的先天免疫通路。
20E‐hydroxyecdysone (20E) plays important roles in larval molting and metamorphosis in insects and is also involved in the insect innate immune response. Insect metamorphosis is a highly successful strategy for environmental adaptation and is the most vulnerable stage during which the insect is susceptible to various pathogens. 20E regulates a series of antimicrobial peptides (AMPs) through the immunodeficiency (IMD) pathway activation in Drosophila; nevertheless, whether other immune pathways are involved in 20E‐regulated insect immunity is unknown. Our previous studies showed that BmMD‐2A is a member of the MD‐2‐related lipid recognition (ML) family of proteins that are involved in the Bombyx mori innate immunity Toll signaling pathway. In this study, we further demonstrate that BmMD‐2A is also positively regulated by 20E, and the BmMD‐2A neutralization experiment suggested that 20E activates some downstream immune effect factors, the AMP genes against Escherichia coli and Staphylococcus aureus, through the regulation of BmMD‐2A in larval metamorphosis, implying that B. mori may use the Toll‐ML signaling pathway to maintain innate immune balance in the larval‐pupal metamorphosis stage, which is a different innate immunity pathway regulated by 20E compared to the IMD pathway in Drosophila.