科學家使用蠶蛹表達純化出具有免疫原性的豬2型圓環病毒病毒樣顆粒

豬2型圓環病毒是能夠導致斷奶仔豬多系統衰竭綜合征的原發病毒。目前該病毒已造成養豬業嚴重的經濟損失。前期研究已經證實，豬2型圓環病毒開放閱讀框2（ORF2）表達的病毒衣殼蛋白（Cap）能夠刺激機體產生有效保護機體免受病毒侵襲的中和抗體。目前，科學家們已經使用過多種不同的蛋白表達系統如原核表達系統、酵母表達系統及昆蟲表達系統，來合成Cap蛋白。但由於原核及酵母表達系統表達的重組病毒Cap蛋白缺乏自發組裝成病毒樣顆粒的裝置，導致其合成的蛋白不能夠有效的刺激機體產生有效的中和抗體。近日，日本的科學家們使用蠶蛹表達系統，對豬2型圓環病毒的Cap蛋白進行表達，發現該表達系統表達的Cap蛋白具有自發組裝成病毒樣顆粒的功能，同時，其蛋白具有刺激機體產生有效抵抗病毒中和抗體的能力。目前，該研究成果已發表至Journal of General Virology雜誌，題為「Purificationand characterization of immunogenic recombinant virus-like particles of porcinecircovirus type 2 expressed in silkworm pupae」。

該研究成果證實蠶蛹表達系統能夠有效的表達出具有良好免疫原性的豬2型圓環病毒病毒樣顆粒蛋白，為開發低成本、安全、有效的防控豬2型圓環病毒感染的亞單位疫苗提供了堅實的基礎。

原文摘要：

Porcine circovirus type 2 (PCV2) is aprimary causative agent of postweaningmultisystemic wasting syndrome (PMWS),which has a significant economic impact on the swine industry. The capsidprotein (Cap) encoded by ORF2 of the viral genome has been used effectively asa vaccine against PCV2 infection. The Cap protein can spontaneously assembleinto virus-like particles (VLPs) that are safe and highly immunogenic forvaccine applications. Several expression systems, including bacteria, yeast andinsect cells, have been utilized to produce PCV2 VLPs. However, in some cases,the recombinant Cap (rCap) proteins produced in bacteria and yeast do notassemble spontaneously. In this study, we expressed rCap protein using asilkworm–baculovirus expression vector system (silkworm–BEVS) for massproduction of PCV2 VLPs and established a simple three-step protocol for itspurification from pupae: extraction by detergent, ammonium sulfateprecipitation and anion exchange column chromatography. Size-exclusionchromatography (SEC) analysis and transmission electron microscope (TEM)observation showed that purified rCap proteins formed VLPs with a similarmorphology to that of the original virus. Furthermore, the VLPs produced insilkworms were capable of inducing neutralizing antibodies against PCV2 inmice. Our results demonstrated that the silkworm system is a powerful tool forthe production of PCV2 VLPs and will be useful for the development of areliable and cost-effective PCV2 vaccine.

喜歡這篇文章嗎？立刻分享出去讓更多人知道吧！