鸡痘病毒复制非必需区的选择对重组鸡痘病毒免疫效力的影响  

Influence of nonessential region on protective efficacy of recombinant Fowlpox viruses

作　　者：孙蕾[1] 刘武杰[1] 陈素娟[1] 石火英[1] 刘秀梵[1] 吴艳涛[1] 张体银[1] 

机构地区：[1]扬州大学,农业部畜禽传染病重点开放实验室,扬州,225009

出　　处：《微生物学报》2005年第3期359-362,共4页Acta Microbiologica Sinica

基　　金：国家"863计划"( 2 0 0 1AA2 13 0 41)~~

摘　　要：母源抗体的干扰是重组鸡痘病毒(FPV)活载体疫苗至今未能得到大规模推广应用的主要原因,而选择适当的FPV复制非必需区可能是解决这一问题的方法之一。根据已发表的美国致病株FPV的基因组设计两对引物,用PCR方法扩增FPV假定复制非必需区的两个侧翼区FPV1和FPV2 ,利用此假定复制非必需区构建FPV表达载体pP12LS及表达ZJ1株新城疫病毒(NDV)F基因的转移载体pP12LSF。pP12LSF与2 82E4株FPV共转染鸡胚成纤维细胞(CEF) ,经数轮蓝斑筛选得到纯化的重组病毒rFPV_FSC。重组FPV在CEF上连续传2 0代仍具有良好的遗传稳定性。对重组FPV进行免疫效力试验,在SPF鸡上,重组病毒rFPV_FSC和与之仅有复制非必需区差异的rFPV_FSB均能抵抗NDV强毒的攻击,提供10 0 %的保护。但在有母源抗体的商品鸡上,rFPV_FSC与rFPV_FSB的免疫效力却有显著差异,保护率分别为10 0 %和6 1 5 4 % ,rFPV_FSC的免疫效力与NDV常规油苗相当。试验结果表明,母源抗体对重组FPV的免疫效力有一定的影响。Because of the interference of maternal antibodies, the recombinant fowlpox virus (rFPV) vaccine has not been used widely. The selection of a well_defined FPV nonessential region might be a desirable way to solve this problem. Two pairs of primers were designed according to the genome of a pathogenic FPV to amplify two flanking regions (FPV1 and FPV2) of the supposed nonessential region by PCR, and then a series of plasmid vectors were constructed to generate the expression vector pP12LS, which containing FPV1, FPV2, the expression cassette of P11_LacZ reporter gene and the promoter Ps. To abtain the vector pP12LSF, the F gene of ZJ1 strain Newcastle Disease Virus (NDV) was inserted into pP12LS, in which the F gene was located downstream of the promoter Ps. pP12LSF was transfected into chicken embryo fibroblast (CEF) pre_nfected with 282E4 strain FPV. The recombinant FPV, rFPV_FSC, was purified by blue plaque selection. The LacZ and F genes could be expressed by rFPV_FSC after 20 successive passages in CEF. The FPV nonessencial region was the only difference between rFPV_FSC and rFPV_FSB. These two rFPVs could induce completely protection in SPF chickens against lethal challenge with F48E8 strain NDV. However, the protective efficacy showed a significant difference in commercial chickens with maternal antibodies. The protective efficacy of rFPV_FSC was 100% and rFPV_FSB was 61.54%. The results indicate that the selection of a well_defined FPV nonessencial region is an effective way to increase the protective efficacy of rFPVs, especially in chickens with maternal antibodies.

关 键 词：鸡痘病毒 复制非必需区 免疫效力 

分 类 号：S852.65[农业科学—基础兽医学]