鸡传染性法氏囊病病毒VP2基因突变对病毒体外复制的影响

摘要

To study the molecular basis for the replication efficiency and virulence of infectious bursal disease virus (IBDV), two amino acid mutations (A222P, D279N) was introduced in to VP2 of IBDV, respectively, based on the information of sequence analysis. Using the reverse genetic research system, two responding mutated strains of IBDV were rescued and their biological characteristics were studied. The replication kinetic curves showed that the rescued virus including A222P replicated over 6 times higher than its parent strain did, while D279N couldn't. Ani- mal experiment of SPF chickens showed that residue 222 and 279 of VP2 did not contribute to virulence of IBDV. The relations between the two residues of VP2 (222, 279) and the replication and virulence of IBDV were reported firstly. The findings provide necessary information for further understanding the gene function of IBDV and the design of new tailored IBDV vaccines.%为了进一步了解影响鸡传染性法氏囊病病毒( IBDV)复制效率和致病力的分子基础,作者在序列分析的基础上,利用反向遗传操作技术,针对VP2上2个重要的氨基酸位点(222和279),修饰和拯救了相应的2株突变病毒,并研究了突变病毒在体内外的生物学特性.复制动力学数据显示,VP2的222位由酪氨酸突变为脯氨酸可将IBDV在鸡胚成纤维细胞(CEF)上的复制滴度提高6倍以上,而279位氨基酸对病毒复制效率无显著影响.SPF鸡的感染试验显示,222位和279位氨基酸与IBDV的致病力没有关系.本研究首次报道了VP2 222位和279位氨基酸与IBDV复制效率和致病力的关系,有助于更加全面地了解IBDV的基因功能,也将为新型IBDV疫苗的设计提供依据和思路.