同时表达蓝舌病毒四个主要结构蛋白可装配成病毒样颗粒

为研制蓝舌病毒（ｂｌｕｅｔｏｎｇｕｅ ｖｉｒｕｓ，ＢＴＶ）基因工程疫苗和进一步研究ＢＴＶ结构与功能的关系，对ＢＴＶ病毒样颗粒（ＶＬＰ）的装配进行了研究。同时在昆虫细胞中表达ＢＴＶ主要结构蛋白ＶＰ７、ＶＰ３、ＶＰ２与ＶＰ５，将细胞裂解液超速离心纯化后，发现主要存在两 形态的颗粒：一种与前文报道的病毒核心颗粒（ＣＬＰ）相同，直径约为６０ｎｍ￣７０ｎｍ，蛋白壳厚１０ｎｍ￣１５ｎｍ；另一种大小为７０ｎｍ￣

Co-expression of Four Major Structural Proteins of Bluetongue Virus Can Assemble into Virus-like Particles

In order to develop novel genetically engineered vaccine for bluetongue virus (BTV) and study the relationship between structure and function of BTV proteins, the assembly of virus-like particles of BTV was conducted in this paper. The four major structural proteins of BTV, VP3, VP7, VP2 and VP5, were expressed simultaneously in insect cells. After purification, two kinds of particles could be found: one was similar to the core-like particles (CLPs) (diameter in 60-70nm, the thickness of the capsid is about 10-15nm) as described before, another was just like empty intact BTV virions (diameter in 70-80nm, the thickness of the capsid was about 20-30nm). Further analysis showed that the expressed particles contain VP2/VP3, VP5 and VP7, but no other BTV proteins or any nucleic acids were found. The expressed particles could elicit neutralizing antibodies and showed hemagglutination activities. It indicated that the four structural proteins could be assembled into virus like particles, though the effectiveness of assembly was relatively low than that of CLPs. The results also implied that the domains related to the assembly of BTV VLPs may be conserved, the interaction between the inner and outer capsid proteins and the initiation of the assembly had nothing to do with the high variation region of VP2.