传染性法氏囊病病毒DNA疫苗的免疫原性研究  

Induction of Protective Immune Response in Chickens Immunized with Plasmid DNA Encoding Antigens of Infectious Bursal Disease Virus

作　　者：于涟[1] 李建荣[1,2] 黄耀伟[1,2] 孟松树[1] 宋厚辉[1] 

机构地区：[1]浙江大学动物预防医学研究所 [2]浙江大学生物医学工程研究所,杭州310027

出　　处：《中国农业科学》2002年第8期995-1001,共7页Scientia Agricultura Sinica

基　　金：国家"86 3"计划资助项目 ( 10 1 j 99 0 2 ) ;国家重点科技项目 ( 96 92 0 34 0 2 )

摘　　要：将传染性法氏囊病病毒弱毒株 (IBDV JD1)和强毒株 (IBDV ZJ2 0 0 0 )的基因组A节段全长cDNA、多聚蛋白 (VP2 /VP4/VP3)和主要宿主保护性抗原 (VP2 )基因 ,分别克隆入两种真核表达载体pCI和 pcDNA3,构建成 12种真核表达质粒。将制备的DNA疫苗以 2 0 0 μg的剂量经腿肌和皮下结合途径首免 14日龄SPF鸡 ,2 8日龄以相同的剂量二免 ,二免后 14d攻击IBDV标准强毒BC6 / 85株。结果表明 ,含A节段或多聚蛋白基因的表达载体均能诱导较高水平的中和抗体并能提供对强毒的免疫保护 ,多聚蛋白基因构建成的DNA疫苗与弱毒苗B87的免疫效果相当 ;编码VP2基因的DNA疫苗仅能诱导很低水平的中和抗体 ,几乎不能提供免疫保护 ;以 pCI为表达载体的免疫效果优于pcDNA3;源于ZJ2 0 0 0株基因构建成的DNA疫苗诱导的免疫反应优于JD1株 ,提示DNA疫苗的免疫效果与VP2蛋白的构象、表达载体的调控元件和毒株差异等因素有关。The full-length genomic segment A, polyprotein(VP2/VP4/VP3) and VP2 gene of two infectious bursal disease viruses, ZJ2000(virulent) and JD1 (attenuated), were amplified by long and accurate PCR in a single step, cloned, sequenced and inserted into the control of CMV promoter and enhancer of pCI and pcDNA3 respectively. Two-week-old specific-pathogen-free (SPF) chickens were inoculated with these plasmid DNA of 200 μg per bird by two routes (intramuscular and intradermal), two weeks later, chickens were boosted with DNA, and at 2 weeks post-boost, they were challenged with Chinese standard virulent strain BC6/85. DNA encoding segment A and polyprotein induced protective immune response, the protection ratio of DNA encoding polyprotein was the same as an attenuated vaccine (B87). However, no antibody and protection were observed with DNA encoding VP2 gene. Vector pCI expressing IBDV antigens was more optimal than that of pcDNA3. The immunogenicity of antigens from the original isolates strain ZJ2000 was better than that of the attenuated strain JD1. These results indicated that the conformation of the antigenic epitopes of main host protective immunogen, the efficacy of absorption and expression of naked DNA, the regulator element of vector and IBDV strains differentiation may play very important roles in influencing the efficacy of IBDV DNA vaccine. DNA vaccine induced protective immunity in chickens opens a new approach to control IBDV.

关 键 词：传染性法氏囊病病毒 DNA疫苗 免疫原性 A节段全长cDNA 多聚蛋白 VP2 

分 类 号：S852.5[农业科学—基础兽医学]