Steroid hormone 20-hydroxyecdysone promotes CTL1-mediated cellular immunity inHelicoverpa armigera
Steroid hormone 20-hydroxyecdysone promotes CTL1-mediated cellular immunity inHelicoverpa armigera
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类固醇激素20-羟基蜕皮酮促进棉铃虫CTL1介导的细胞免疫
DOI：
10.1111/1744-7917.12851
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发表时间：
2021
期刊：
影响因子：
4
通讯作者：
Wang Jia-Lin
中科院分区：
文献类型：
--
作者：
Wang Gui-Jie;Wang Wen-Wen;Liu Yu;Chai Lian-Qin;Wang Guo-Xiu;Liu Xu-Sheng;Wang Yu-Feng;Wang Jia-Lin
中华卵索线虫（Ovomermis sinensis）等索线虫是防治棉铃虫（Helicoverpa armigera）等多种害虫的生物防治剂。然而，鉴于宿主强大的免疫系统，中华绒螯蟹的感染率较低，从而限制了其广泛应用。为了了解宿主对索线虫的防御机制，我们鉴定并表征了一种参与识别中华绒螯蟹的蛋白质，即从中华绒螯蟹表面洗脱的潜在的中华绒螯蟹结合蛋白C型凝集素1（HaCTL 1a和/或HaCTL 1b）。中华棉铃虫幼虫经棉铃虫浆孵育后的生长情况。HaCTL 1b与已报道的HaCTL 1a蛋白同源。HaCTL 1主要在血细胞中表达，由类固醇激素20-羟基蜕皮激素通过蜕皮激素受体（HaEcR）或超气门（HaUSP）或两者诱导。结合实验证实HaCTL 1蛋白与中华按蚊相互作用，但与武昌罗索线虫不相互作用。此外，HaCTL 1蛋白被分泌到血腔中，并促进血细胞介导的包裹和吞噬作用。HaEcR和/或HaUSP的敲低导致受损的包封和吞噬作用。因此，HaCTL 1似乎在抵抗寄生线虫的防御中调节细胞免疫，并且20-羟基蜕皮激素-HaEcR-HaUSP复合物参与调节该过程。
Mermithid nematodes, such asOvomermis sinensis, are used as biological control agents against many insect pests, including cotton bollworm (Helicoverpa armigera). However, given the host's robust immune system, the infection rate ofO.sinensisis low, thus restricting its widespread use. To understand the host defense mechanisms against mermithid nematodes, we identified and characterized a protein involved in the recognition ofO.sinensis, the potentialO.sinensis‐binding protein C‐type lectin 1 (HaCTL1a and/or HaCTL1b), which was eluted from the surface ofO. sinensisafter incubation withH.armigeraplasma. HaCTL1b is homologous to the previously reported HaCTL1a protein. HaCTL1 was predominantly expressed in hemocytes and was induced by the steroid hormone 20‐hydroxyecdysone through ecdysone receptor (HaEcR) or ultraspiracle (HaUSP), or both. Binding assays confirmed the interactions of the HaCTL1 proteins withO.sinensisbut not withRomanomermis wuchangensis, a parasitic nematode of mosquito. Moreover, the HaCTL1 proteins were secreted into the hemocoel and promoted hemocyte‐mediated encapsulation and phagocytosis. A knockdown of HaEcR and/or HaUSP resulted in compromised encapsulation and phagocytosis. Thus, HaCTL1 appears to modulate cellular immunity in the defense against parasitic nematodes, and the 20‐hydroxyecdysone–HaEcR–HaUSP complex is involved in regulating the process.