敲除meq的鸡马立克氏病毒强毒株对超强毒的免疫保护作用  

Protective immunity of a meq-deleted Marek’s disease virus against very virulent virus challenge in chickens

作　　者：苏帅[1] 李延鹏[2] 孙爱军[1] 赵鹏[1] 丁家波[3] 朱鸿飞[2] 崔治中[1] 

机构地区：[1]山东农业大学动物科技学院,泰安271018 [2]中国农业科学院北京畜牧兽医研究所,北京100081 [3]中国兽医药品监察所,北京100081

出　　处：《微生物学报》2010年第3期380-386,共7页Acta Microbiologica Sinica

基　　金：国家自然科学基金(30671571)~~

摘　　要：【目的】比较和评价一株敲除了meq基因的马立克氏病毒(MDV)的致病性及其诱发的保护性免疫作用。【方法】将1日龄SPF鸡150只随机分为5组,每组30只,分别饲养于正压过滤空气的SPF动物饲养隔离罩内。1日龄时,第1和第5组鸡以2000PFU/只的剂量腹腔接种GX0101Δmeq,第2组鸡以2000PFU/只的剂量腹腔接种CVI988/Rispens疫苗株,第3和第4组鸡不接种任何病毒作为对照组。免疫接种5d后,第1、2、3组分别以500PFU/只的剂量攻击MDV超强毒株vvrMd5。饲养90d,观察死亡情况,对各组死亡鸡只剖检,并取疑似马立克特有病变脏器做石蜡切片,于攻毒后90d处死全部存活鸡并随机取心脏、肝脏、脾脏做病理切片。【结果】单独接种GX0101Δmeq的第5组没有任何马立克氏病临床症状和特有的组织学病变,接种GX0101Δmeq再感染超强毒株vvrMd5的第1组也没有马立克病特有的组织学病变,但CVI988/Rispens免疫后感染超强毒株vvrMd5的第2组显示马立克病特有病变的病理切片比例为9/42,单独接种超强毒株vvrMd5的第3组死亡率为87%,死亡鸡出现可眼观典型肿瘤率为25%,免疫接种GX0101Δmeq和CVI988/Rispens的第1组和第2组对超强毒株vvrMd5攻击的保护指数分别为100%和89%。【结论】本实验构建的MDVmeq基因缺失株-GX0101Δmeq可在体外稳定复制,不仅对SPF鸡没有致病性和致瘤性,而且能诱导比CVI988/Rispens疫苗株更好的对超强毒MDV的免疫保护效果。[Objective]To evaluate the pathogenicity and immunoprotective effect of a wild strain of Marek’s Disease Virus （MDV） after deleting of its meq oncogene. [Methods] Total 150 one-day-old SPF chickens were divided into 5 groups of 30 birds each and kept in 5 isolators with positive pressure-filtered air. At first day, 2000 PFU of meq-deleted GX0101Δmeq were inoculated intra-abdominally （i.a.） into each bird in groups 1 and 5, 2000 PFU of commercial vaccine CVI988/Rispens were injected i.a. for group 2. No viral challenge was made in groups 3 and 4 as controls. Five days later, chickens in groups 1, 2, 3 were challenged i.a. with very virulent （vv） MDV strain rMd5. During 90 days after challenge, all dead birds were recorded and checked for necropsy. The tumor-suspected tissues were examined by histo-sections. In the end, all survival birds were killed for necropsy. The samples of heart, liver and spleen were collected for histo-sections.[Results] Challenge with vv rMd5 caused 87% mortality and 25% of dead birds with gross tumors in non-vaccinated chickens of group 3 but there was no mortality in group 5 inoculated with GX0101Δmeq. Commercial vaccine CVI988/Rispens gave 89% protective index against vv rMd5 challenge and there were 9/42 histo-sections with suspected lymphocyte filtrated nodules in group 2. But vaccination with GX0101Δmeq provided 100% protective index against challenge with vv rMd5 and there was no tumor lesion even in histo-sections in group 1.[Conclusion] The meq-deleted mutant GX0101Δmeq is able to replicate in cell cultures stably, it has no pathogenicity and oncogenicity to chickens and is able to induce better protective immunity against vvMDV challenge than commercial vaccine CVI988/Rispens.

关 键 词：马立克氏病病毒 meq基因敲除 致病性 致瘤性 免疫保护作用 

分 类 号：S852.65[农业科学—基础兽医学]