禽白血病病毒J亚群跨种传播研究  

Cross-species Transmission of Avian Leukosis Virus Subgroup J

作　　者：申艳玮[1] 何孟莲[2,1] 张吉[1] 赵满达 王桂花[1] 成子强[1] 

机构地区：[1]山东农业大学动物科技学院,泰安271018 [2]山东畜牧兽医职业学院动物科技系,潍坊261061

出　　处：《病毒学报》2016年第1期46-55,共10页Chinese Journal of Virology

基　　金：山东省家禽产业体系(SDAIT-13-011-04)

摘　　要：禽白血病病毒J亚群(ALV-J)为致瘤性禽反转录病毒,主要引起髓细胞瘤。ALV-J囊膜基因的高频突变率使其具有了跨种传播的潜力。为探索ALV-J在宿主选择压力下是否可实现跨种传播,本研究以ALV-J顺次感染易感宿主禽(SPF鸡,火鸡),然后过渡到抗性宿主禽(山鸡,鹌鹑和鸭),检测排毒规律、观察病理变化、分析分离株囊膜基因(env)遗传突变。结果显示,通过对ALV-J体内选择压的逐级建立,实现了对抗性宿主山鸡和鹌鹑的感染,但鸭未感染,而用原代毒直接攻毒抗性禽则未出现感染。SPF鸡和火鸡感染率均为100%(16/16),而山鸡和鹌鹑的感染率分别为37.5%(6/16)和10%(3/30)。感染宿主均呈免疫耐受状态,并可见肝脏、脾脏、肾脏及心血管系统炎症反应和组织损伤。通过有义突变与沉默突变比值(NS/S)分析,山鸡毒株和鹌鹑毒株超变区hr2的NS/S值均为2.5,由此可知山鸡和鹌鹑ALV-J分离株的突变是由宿主选择压造成的,且提示hr2区突变是ALV-J实现跨种传播的关键区域。序列同源性分析发现火鸡、山鸡和鹌鹑ALV-J分离株与原始毒逐渐远离,而与ALV-J原型株HPRS-103株却呈接近趋势,但HPRS-103不感染山鸡和鹌鹑,其机制还有待于进一步研究。Avian leukosis virus subgroup J（ALV-J）is an avian retrovirus that can induce myelocytomas.A high-frequency mutation in gene envelope endows ALV-J with the potential for cross-species transmission.We wished to ascertain if the ALV-J can spread across species under selection pressure in susceptible and resistant hosts.First,we inoculated（in turn）two susceptible host birds（specific pathogen-free（SPF）chickens and turkeys）.Then,we inoculated three resistant hosts（pheasants,quails and ducks）to detect the viral shedding,pathologic changes,and genetic evolution of different isolates.We found that pheasants and quails were infected under the selective pressure that accumulates stepwise in different hosts,and that ducks were not infected.Infection rates for SPF chickens and turkeys were 100%（16/16）,whereas those for pheasants and quails were 37.5%（6/16）and 11.1%（3/27）.Infected hosts showed immune tolerance,and inflammation and tissue damage could be seen in the liver,spleen,kidneys and cardiovascular system.Non-synonymous mutation and synonymous ratio（NS/S）analyses revealed the NS/S in hypervariable region（hr）2of pheasants and quails was 2.5.That finding suggested that mutation of isolates in pheasants and quails was induced by selective pressure from the resistant host,and that the hr2 region is a critical domain in cross-species transmission of ALV-J.Sequencing showed that ALV-J isolates from turkeys,pheasants and quails had moved away from the original virus,and were closer to the ALV-J prototype strain HPRS-103.However,the HPRS-103 strain cannot infect pheasants and quails,so further studies are needed.

关 键 词：禽白血病病毒J亚群(ALV-J) 跨种传播 选择压 遗传变异 

分 类 号：S852.65[农业科学—基础兽医学]