蓝舌病病毒VP5蛋白增强VP2蛋白中和抗体产生的机制研究

Bluetongue virus (BTV), the prototype of the genus Orbivirus within the family Reoviridae, is the causative agent of bluetongue disease which is a vector-borne viral disease of ruminants. VP2 and VP5 are two major structural proteins of BTV and play a key role in inducing serotype-specific neutralizing antibody. It has been demonstrated before that immunization with VP2 and VP5 mixture can increase the titer of neutralizing antibody against VP2. However, it is unknown that the mechanism of VP5 protein enhances neutralizing antibody production against VP2 protein of BTV. In order to investigate its mechanism, BTV16 VP5 and VP2 will be used as immunogens to determine the correlation between the production of neutralizing antibody against VP2 and VP5. Meanwhile, epitopes in VP2 will be comprehensively mapped and the interference between difference epitopes and neutralizing antibody production was evaluated to analysis if the existence of VP5 would disturb the submission of difference epitopes. Additional, the interaction regions between VP5 and VP2 will be identified by the technology of surface plasma resonance (SPR) and their function will be confirmed by a site-directed mutagenesis. Finally, comprehensively analyze the mechanism of VP5 enhances neutralizing antibody production against VP2. This study will enrich and provide new scientific information for interaction mechanism of outer capsid proteins of BTV and vaccine development.

蓝舌病是由呼肠孤病毒科环状病毒属蓝舌病病毒（BTV）引起的经媒介昆虫传播的反刍动物传染病。VP2与VP5是BTV两个主要结构蛋白，直接决定病毒的免疫保护特性。研究表明，VP5与VP2联合免疫可以提高VP2所产生的中和抗体的滴度，然而这种增强作用的机制尚不清楚。为了阐明VP5增强VP2中和抗体产生的具体机制，以BTV16型VP2与VP5为免疫原，采用传统血清学检测技术确定VP2中和抗体的产生与VP5之间的关系，并对不同免疫时期VP2的表位图谱进行绘制，评估差异表位是否对中和抗体的产生有所干扰，分析VP5的存在对差异表位的递呈是否产生影响；此外，利用表面等离子共振技术（SPR）确定VP5与VP2相互作用的区域并进行突变研究，评估突变后VP5 对VP2免疫效果的影响。旨在阐明VP5增强VP2中和抗体产生的机制，为BTV外衣壳蛋白互作机制研究以及疫苗研制提供新的科学依据。

蓝舌病是由呼肠孤病毒科环状病毒属蓝舌病病毒（BTV）引起的经媒介昆虫传播的反刍动物传染病。VP2与VP5是BTV两个主要结构蛋白，直接决定病毒的免疫保护特性。本研究表明，不论是构建重组病毒还是体外表达VP5与VP2蛋白，二者联合免疫可以提高中和抗体的滴度。为了阐明这种现象产生的具体机制，我们排列不同的免疫组合，确定VP5的蛋白130-280位氨基酸区域可以较好的提高VP2免疫产生的中和抗体；同时利用短肽扫描与噬菌体展示技术，确定了各种免疫组合所产生的抗VP2抗体的表位图谱；此外，利用表面等离子共振技术（SPR）确定VP5与VP2相互作用的区域，但是发现VP5蛋白截短后与VP2互作力变弱，与对照比较差异不明显。本研究初步阐明VP5增强VP2中和抗体产生的机制，为BTV外衣壳蛋白互作机制研究以及疫苗研制提供新的科学依据。