DNA免疫诱导SPF鸡对传染性法氏囊病的免疫保护反应  

DNA Immunization Elicits Protection to Lethal Challenge with vvIBDV but Failure to Prevent Clinic Sign and Bursal Lesion

作　　者：步志高[1] 赵晓岩[1] 刘长军[1] 王笑梅[1] 于康震[1] 徐宜为[1] 

机构地区：[1]中国农业科学院哈尔滨兽医研究所,哈尔滨150001

出　　处：《中国预防兽医学报》2000年第5期325-328,共4页Chinese Journal of Preventive Veterinary Medicine

摘　　要：传染性法氏囊病病毒 (IBDV)D78株VP2基因插入真核表达质粒pCICMV启动子下游多克隆位点 ,构成pCIVP2用于 3周龄SPF雏鸡DNA免疫。试验鸡每羽腿部肌肉注射pCIVP2 10 0 μg,2周后加强免疫一次 ;二免 2周后 ,人工感染vvIBDVG株。结果 ,两次免疫后血清中和抗体试验组为阳性而对照组为阴性 ;试验组攻毒后发病 11/ 11,攻毒后 1周存活 10 / 11,所有存活鸡法氏囊较正常中度或轻度萎缩 ;对照组发病 6 / 6 ,病死 5 / 6 ,存活 1/ 6 ;存活鸡法氏囊较正常严重萎缩。组织病理学观察表明 ,无论法氏囊淋巴滤泡面积还是其中的淋巴细胞数量 ,免疫试验组都要远远大于或多于免疫对照组。结果表明 ,VP2基因DNA免疫可诱导SPF鸡产生中和抗体 ,并形成对IBDV超强毒株致死攻击的免疫保护 ,虽不能阻止临床发病及法氏囊病理损伤发生 ,但有可能减缓法氏囊病理损伤程度。The experiment was carried out to explore DNA vaccination against chicken infectious busal disease(IBD).VP2 gene cDNA originating from IBDV D78 strain by RT_PCR was sequenced to confirm the ORF integratity. and then inserted into pCI multiple clone site at downstream of CMV promoter_enhancer_intron and upstream to form pCIVP2 as DNA vaccination used in 3_week old chicken.Immune test group were inoculated with pCIVP2 100μg per chicken intramuscularly and boosted with the same dose 2 weeks later.At 4 weeks after priming,both group chickens challenged with 10 2 ELD 50 vvIBDV G strain.Results,all chickens in both group showed clinical sign at 3 days post challenge while the mortality was much different between pCIVP2 vaccinated and control,i.e.1/11 and 5/6 respectively.The observation of gross and histopathology revealed that there was more serious bursal atrophy and follicle lymphocyte delete occurred in control survival chickens than pCIVP2 vaccinated survival chickens.VN antibody test also yielded different titers at pre_challenge between pCIVP2 group and control with the 10 1.5 of former and negative of latter.These results indicated that VP2 DNA immunization elicits VN antibody and immune protection against vvIBDV challenge,though failure to prevent clinic sign and bursal lesion.

关 键 词：DNA免疫 VP2基因 传染性法氏囊病病毒 鸡 

分 类 号：S858.315.3[农业科学—临床兽医学]