中文摘要：

根据GenBank中发表的新城疫病毒（NDV）融合蛋白（F）基因序列，设计1对引物，通过RT—PCR扩增出鹅源NDV分离株JS5F基因（约1700bp），测序确认后，将其克隆入真核表达载体pVAX1．获得重组真核表达质粒pVAX1-F。pVAX1-F经脂质体转染COS-7细胞。间接免疫荧光试验检测出F基因在COS-7细胞中的表达产物。将pVAX1-F转化减毒鼠伤寒沙门氏菌SL7207，构建成功携带DNA疫苗的重组沙门氏菌SL7207（pVAX1-F）。重组菌以10。CFU／只的剂量2次免疫BALB／c小鼠，免疫小鼠可以检测到特异性针对NDVF蛋白的血清抗体和小肠粘膜抗体应答，SL7207（pVAX1-F）免疫组抗体水平显著高于SL7207（pVAX1）组（P〈0．05）。将SL7207（pVAX1-F）以10。CFU／只剂量口服免疫1日龄雏鸡，免疫保护试验结果显示，SL7207（pVAX1-F）免疫组对鸡具有良好的保护率（77．27％），与空白对照组和SL7207（pVAX1）空载体组之间存在显著性差异（P〈0．05）。结果表明，该运送DNA疫苗的减毒沙门氏菌系统在体内能成功释放所携带的质粒，并能刺激机体产生免疫应答，可对NDV强毒攻击提供良好的免疫保护作用，提示该疫苗候选株对新城疫的控制有重要应用前景。

英文摘要：

A pair of primers were designed and synthesized according to the previously published sequence of fusion protein（F） gene of Newcastle disease virus（NDV） and used to amplify F gene by reverse-transcrlption polymerase chain reaetion（RT PCR） from the genomie RNA of a NDV strain JS5 isolated from goose, The PCR prod- uct was identified by sequencing. Then recombinant eukaryotic expression vector pVAX1-F was constructed through inserting F gene into MCS of pVAX1. The recombinant plasmid pVAX1-F was transfected in COS-7 cells, and identified for the transient expression of F gene by indirect immunofluorescent assay. Finally,the recombinant plasmid was transformed into attenuated Salmonella typhimurium SL7207, The recombinant was screened and designated as SL7207 （pVAX1-F）. This recombinant bacterial could significantly elicit specific serum and intestinal mucosal antibody immune response in immunized BALB/c mice ,compared with SL7207 （pVAX1） immunized mice. 1-day-old commercial ISA brown chickens were immunized orally with SL7207（pVAX1-F） at dosage of 109 CFU at two weeks interval. The chickens immunized with SL7207（pVAX1-F） could be protected with the protective rate of 77.27% ,significantly higher than those with SL7207（pVAX1）（29.42%） or PBS（12.5% ） （P〈0.05）, These results demonstrated that the Salmonella delivering system could release haboured NDV DNA vaccines in viva and elicit spcific immune response. A novel mucosal DNA vaccine was developed and would be useful for controlling the infection and epidemic of ND in the poultry.