20-Hydroxyecdysone promotes release of GBP-binding protein from oenocytoids to suppress hemocytic encapsulation.
20-Hydroxyecdysone promotes release of GBP-binding protein from oenocytoids to suppress hemocytic encapsulation.
复制标题
DOI：
10.1016/j.ibmb.2017.11.006
复制
发表时间：
2018
影响因子：
3.8
通讯作者：
Xiao-Rong Zhuo;Lei Chen;Gui-Jie Wang;Xu-Sheng Liu;Yu-Feng Wang;Ke Liu;Xiao-qiang Yu;Jia‐Lin Wang-Jia
中科院分区：
文献类型：
--
作者：
Xiao-Rong Zhuo;Lei Chen;Gui-Jie Wang;Xu-Sheng Liu;Yu-Feng Wang;Ke Liu;Xiao-qiang Yu;Jia‐Lin Wang-Jia
生长阻滞肽(GBP)是一种昆虫细胞因子，可以刺激浆细胞的黏附，从而在包膜反应中发挥关键作用。以前已经证明，GBP结合蛋白(GBPB)是在类卵泡细胞裂解时释放出来的，负责随后从血淋巴中清除GBP。然而，目前对GBPB的了解有限，昆虫通过增加GBPB水平来灭活GBP的机制在很大程度上仍未被探索。在这里，我们已经从棉铃虫中鉴定出一个GBP前体基因(HaGBP前体)和两个GBPB基因(命名为HaGBPB1和HaGBPB2)。HaGBP前体主要在脂肪体中表达，而HaGBPB1和HaGBPB2主要在血细胞中表达。免疫学分析表明，在游荡阶段，HaGBPB1和HaGBPB2都从血细胞释放到血浆中。此外，20-羟基蜕皮酮(20E)处理或珠状刺激可促进HaGBPB1和HaGBPB2至少部分地从类卵泡细胞释放到血浆中。此外，我们还证明了HaGBPB1的N端负责与HaGBP结合，并抑制HaGBP诱导的浆细胞扩散和包膜。总之，这项研究有助于丰富我们对20E通过GBP-GBPB相互作用调节浆细胞黏附和包膜的分子机制的理解。
Growth-blocking peptide (GBP) is an insect cytokine that stimulates plasmatocyte adhesion, thereby playing a critical role in encapsulation reaction. It has been previously demonstrated that GBP-binding protein (GBPB) is released upon oenocytoid lysis in response to GBP and is responsible for subsequent clearance of GBP from hemolymph. However, current knowledge about GBPB is limited and the mechanism by which insects increase GBPB levels to inactivate GBP remains largely unexplored. Here, we have identified oneGBP precursor(HaGBP precursor) gene and twoGBPB(namelyHaGBPB1andHaGBPB2) genes from the cotton bollworm,Helicoverpa armigera. TheHaGBP precursorwas found to be predominantly expressed in fat body, whereasHaGBPB1andHaGBPB2were mainly expressed in hemocytes. Immunological analyses indicated that both HaGBPB1 and HaGBPB2 are released from hemocytes into the plasma during the wandering stage. Additionally, 20-hydroxyecdysone (20E) treatment or bead challenge could promote the release of HaGBPB1 and HaGBPB2 at least partly from oenocytoids into the plasma. Furthermore, we demonstrate that the N-terminus of HaGBPB1 is responsible for binding to HaGBP and suppresses HaGBP-induced plasmatocyte spreading and encapsulation. Overall, this study helps to enrich our understanding of the molecular mechanism underlying 20E mediated regulation of plasmatocyte adhesion and encapsulation via GBP-GBPB interaction.