Inhibition of host cell encapsulation through inhibiting immune gene expression by the parasitic wasp venom calreticulin.
Inhibition of host cell encapsulation through inhibiting immune gene expression by the parasitic wasp venom calreticulin.
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DOI：
10.1016/j.ibmb.2013.07.010
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发表时间：
2013-10
影响因子：
3.8
通讯作者：
Lei Wang;Qi Fang;C. Qian;Fei Wang;Xiao-qiang Yu;G. Yè
中科院分区：
文献类型：
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作者：
Lei Wang;Qi Fang;C. Qian;Fei Wang;Xiao-qiang Yu;G. Yè
寄生蜂将毒液注入宿主体内，以保护其后代免受宿主免疫反应的影响。在我们以前的研究中，我们在蝶蛹金小蜂毒液中鉴定了一种钙网蛋白（CRT）。本研究在大肠杆菌中表达了野生型和卷曲螺旋结构域缺失型蛹虫草钙网织蛋白（PpCRT），并制备了兔抗PpCRT的多克隆抗体。Western blot分析表明，PpCRT蛋白不仅存在于毒液中，而且存在于所有测试的组织中。真实的时间PCR结果表明PpCRT mRNA在毒腺中有高表达。PpCRT在毒腺中的转录水平在羽化后2天达到峰值，而毒液中的PpCRT蛋白维持在恒定水平。重组野生型和突变型PpCRT蛋白可以结合到P.puparumegs的表面。重组PpCRT在体外可抑制宿主粉蝶血细胞铺展和细胞包裹，卷曲螺旋结构域对PpCRT的抑制作用很重要。免疫细胞化学结果显示PpCRT进入油菜血细胞，卷曲螺旋结构域在此过程中起作用。真实的PCR结果表明，重组PpCRT对菜青虫体内钙网蛋白和清道夫受体基因的转录水平有明显的抑制作用。因此，我们的研究结果表明蛹虫草毒通过其功能成分PpCRT抑制宿主细胞免疫反应相关基因的表达来保护其后代免受宿主细胞免疫反应的影响。
Parasitoid wasps inject venom into the host to protect their offspring against host immune responses. In our previous study, we identified a calreticulin (CRT) inPteromalus puparumvenom. In this study, we expressed the wild-type and the coiled-coil domain deletion mutantP.puparumcalreticulins (PpCRTs) inEscherichia coliand prepared polyclonal antibody in rabbit against PpCRT. Western blot analysis showed that PpCRT protein was not only present in the venom but also in all the tissues tested. Real time PCR results indicated that PpCRT mRNA was highly expressed in the venom gland. The transcript level of PpCRT in the venom gland was peaked at 2 days post-eclosion, while the PpCRT protein in the venom was maintained at a constant level. Both recombinant wild-type and mutant PpCRT proteins could bind to the surface ofP.puparumeggs. Recombinant PpCRT inhibited hemocyte spreading and cellular encapsulation of the hostPieris rapae in vitro, and the coiled-coil domain is important for the inhibitory function of PpCRT. Immunocytochemistry results showed that PpCRT enteredP.rapaehemocytes, and the coiled-coil domain played a role in this process. After injection of recombinant PpCRT intoP.rapaepupae, real time PCR results showed that PpCRT inhibited transcript levels of host encapsulation-related genes, including calreticulin and scavenger receptor genes. In conclusion, our results suggest thatP.puparumvenom protects its offspring against host cellular immune responses via its functional component PpCRT to inhibit the expression of host cellular response-related genes.