IBDV病毒样颗粒诱导树突状细胞成熟与迁移的免疫机制研究

Infected bursal disease(IBDV), is a kind of highly contagious and high incidence disease that the causative agent is infected bursal disease virus, which resulting in immune failure by damaging chicken immune organs. The major structure protein VP2 self-assembling into VLPs play an important role in immune protection. At present, the natural immune mechanism after vaccination is not clear. According to the professionalism of DCs, the study is intended to assemble IBDV VLPs with good immunogenicity and makes the mice DCs be the research target. After all, the molecular mechanism of inducing DCs maturation and migration in vitro can be further research by using the method of molecular biology, cell biology and system of immunology technology, the migration pathway and recursion effect of DCs capture IBDV VLPs in vivo were revealed, and the humoral immunity and cellar immunity of VLPs are used to be analyzed and evaluated by the mouse model. This study provides theoretical and scientific basis for the in-depth study of IBDV VLPs activation in natural immune response mechanism.

鸡传染性法氏囊病(IBD)是由传染性法氏囊病病毒(IBDV)引起的一种严重危害雏鸡免疫器官，致使雏鸡免疫失败的高发性、高接触性的病毒性传染病。IBDV主要结构蛋白VP2自组装的病毒样颗粒（VLPs）在IBDV免疫中起重要的保护作用。目前对于IBDV VLPs疫苗接种后的天然免疫机制尚不清楚，因此本研究拟组装具有良好免疫原性的病毒样颗粒IBDV VLPs，以小鼠树突状细胞（DCs）为研究靶点，根据DCs细胞APC的专职性，利用分子生物学方法、细胞生物学分析手段以及系统免疫学技术体系，深入探讨IBDV VLPs诱导体外DC成熟与迁移的分子机制，揭示体内DCs捕获IBDV VLPs后的迁移路径及递呈效应，通过研究分析IBDV VLPs激发的体液和细胞免疫应答水平并评价其免疫原性。为深入阐明IBDV VLPs激活天然免疫应答机制提供理论基础和科学依据。

Infectious bursal disease virus (IBDV) is a highly contagious, acutely infectious agent that causes immunosuppression in chickens.In this study, we used Escherichia coli (E. coli) to express IBDV VP2 protein, which can self-assemble into virus like particles (VLPs) with a diameter of about 25 nm and high uniformity. The VLPs were used as immunogen mixed with MontanideTM ISA 71VG, ISA 71RVG or white oil adjuvants. These test vaccines were intramuscularly injected into 19-day-old SPF chickens. The immunization results showed that the adjuvants boosted antibody production, and the adjuvant groups (except white oil) produced higher antibody levels than the non-adjuvanted controls and the commercial vaccine groups. In terms of cellular immunity, the VLPs plus adjuvant combinations produced higher levels of cytokines, IL-2, IL-4, and IFN-γ, than the controls. In conclusion, IBDV VP2 VLPs plus ISA 71RVG adjuvant can be used as an optimal vaccine combination for improving the immune efficacy.