Asia1型口蹄疫病毒受体结合位点多样性  

Diversity of receptor recognition site of type Asia1 foot-and-mouth disease virus

作　　者：李平花[1,2] 白兴文[2] 孙普[2] 卢曾军[2] 曹伟军[2] 吴润[1] 殷宏[2] 刘在新[2] 

机构地区：[1]甘肃农业大学动物医学院,兰州730070 [2]中国农业科学院兰州兽医研究所,家畜疫病病原生物学国家重点实验室,农业部畜禽病毒学重点实验室,国家口蹄疫参考实验室,兰州730046

出　　处：《微生物学报》2011年第3期423-428,共6页Acta Microbiologica Sinica

基　　金：国家”973项目”(2005CB523201);国家支撑计划(2006BAD06A12)~~

摘　　要：【目的】口蹄疫病毒(Foot-and-Mouth Disease Virus,FMDV)通过结构蛋白VP1 G-H环上高度保守的精氨酸-甘氨酸-天门冬氨酸(Arg-Gly-Asp,RGD)基序与整联蛋白结合起始病毒的感染,但FMDV是RNA病毒,在环境条件变化时,FMDV能够以非RGD的途径起始病毒的感染。为了研究FMDV Asia1/JS/China/05田间舌皮毒经两种不同的途径短期传代后细胞受体结合基序RGD的变异。【方法】采用RT-PCR方法扩增FMDV Asia1/JS/China/05田间毒、田间毒的乳鼠适应毒第四代(MF4)和接种田间毒的牛同居感染的猪水泡病料适应细胞的第八代毒(PBF8)结构蛋白VP1基因,并对不同病毒VP1基因的PCR产物测序和cDNA文库测序。【结果】以含RGD受体结合基序为优势的田间毒在乳鼠上短期传代后出现了含精氨酸-丝氨酸-天门冬氨酸(Arg-Ser-Asp,RSD)和RGD受体结合基序的混合种群,而同居感染后的细胞传代病毒种群则以含精氨酸-天门冬氨酸-天门冬氨酸(Arg-Asp-Asp,RDD)受体结合基序为优势种群。【结论】发现了含RGD受体结合位点为优势的FMDV种群,经不同的宿主短期传代后产了含RSD或RDD受体结合基序的优势种群,该发现不仅增加了保守基序RGD发生替换的FMDV变异株的数量,而且为FMDV的细胞识别和宿主嗜性的改变等进一步研究奠定了物质基础。[objective]Foot-and-Mouth Disease Virus（FMDV） initiates infection by binding to integrin receptors via a highly conserved Arg-Gly-Asp（RGD） sequence found in the G-H loop of the structural protein VP1.However,FMDV is an RNA virus,which harbors the evolutionary potential to render the RGD motif dispensable upon changes in constant environment.We studied mutation of RGD motif upon short-time passages FMDV Asia1 /JS /China /2005 field strain in different host.[Methods]VP1 gene was amplified from Asia1 /JS /China /05 field strain,the fourth passage virus in sulking mice（MF4） of the above strain and the virus isolated from a pig housing with cattle inoculated with the above strain followed eight passages in BHK-21 cell（PBF8） by RT-PCR,and the VP1 genes were sequenced and their deduced amino acid sequences were compared with each other.[Result]Dominant population with RGD and Arg-Ser-Asp（RSD） receptor recognition site motif was generated after four passages of Asia1 /JS /China /2005 field virus in sulking mice and another dominant population with Arg-Asp-Asp（RDD） motif was produced after eight passages the virus isolated from housing pig with cattle inoculated with the above field strain.[Conclusion]This study indicated that the dominant FMDV virus populations with RSD or RDD receptor binding site instead of original RGD motif were produced upon short-time evolution of FMDV field isolates with RGD motif in different environment.These studies not only increase number of viable mutants with substitutions in the RGD region,but also these profoundly altered,but viable,mutants with different receptor recognition site will provide useful tools for studies of cell recognition by FMDV and host tropism modifications.

关 键 词：口蹄疫病毒 受体结合位点 多样性 

分 类 号：S852.65[农业科学—基础兽医学]