一株强神经毒力乙脑病毒株的生物学及其分子特征  

Studies on the Biological and Genetic Characteristics of a Highly Neurovirulent Japanese Encephalitis Virus Strain SA4

作　　者：刘欣玉[1] 俞永新[1] 岳广智[1] 杨立宏[1] 贾丽丽[1] 董关木[1] 

机构地区：[1]中国药品生物制品检定所,北京100050

出　　处：《病毒学报》2010年第4期265-270,共6页Chinese Journal of Virology

摘　　要：研究一株神经毒力很强的乙型脑炎病毒株SA4株的生物学特性并进行基因组全序列分析,并找到其毒力强的分子基础。将SA4脑内接种昆明小鼠后每日观察发病和死亡鼠数并每日收取鼠脑,用空斑法检测接种后不同时间点的脑内病毒增殖滴度,同时以另一株乙脑病毒SA14按照相同方法进行平行实验作为对照。SA4株的全基因组测序序列结果与乙脑SA14株及世界各地共21株乙脑病毒的全基因组序列进行比较。结果显示,脑内接种SA4株的小鼠发病和死亡时间均比SA14株早1d,在相同时间点上SA4株的病毒滴度高0.5～1.0lgPFU/mL。SA4株与世界各地毒株基因同源性比对,核苷酸同源性为84.6%～99.0%,氨基酸同源性为95.2%～99.7%。与SA14相比,氨基酸序列存在17个位点的差异,分布于不同的区段,其中E区最多,为5个。证明SA4是一株在脑内具有较快繁殖力的神经毒力很强的毒株,其序列上17个氨基酸位点的替换很可能是其强神经毒力的分子基础。The biological and genetic characteristics of a highly neurovirulent JE virus strain SA4 were studied.Mice were inoculated intracerebrally with strain SA4 and SA14,and observed for 14 days,respectively.On different days,mice brains were harvested for titrations of the virus content in the brains.Full-length genome of SA4 was sequenced and compared with SA14 as well as other JE virus strains in the world.The results indicated that the mice inoculated by SA4 induced sickness and death more rapidly（24 hours faster）than those induced by the SA14.The virus titers in the brains of mice infected with SA4 were 0.5-1.0 lg PFU/mL higher than that infected with SA14.The sequence comparison indicated that the nucleotide and amino acid homology between SA4 and the other 21 JE strains were 84.6%-99.0% and 95.2%-99.7% respectively.Comparison with strain SA14 revealed that there were 17 amino acid differences between the two strains,of which 5 were in the E protein region.The results demonstrate that strain SA4 is a highly neurovirulent strain.The substitutions of the 17 amino acids in the SA4 strain can be the molecular basis for the biological characteristics of high neurovirulence.

关 键 词：乙型脑炎病毒株 SA4株 神经毒力 全基因序列 

分 类 号：R373.3[医药卫生—病原生物学]