摘要
１９９０年和１９９３年，从云南瑞丽县感染ＨＩＶ的静脉注射毒品者中采血，分离白细胞，用ＰＣＲ方法扩增ＨＩＶ１膜蛋白基因（ｅｎｖ）并克隆。核苷酸序列分析由手工和ＡＢＩ公司ＤＮＡ序列分析仪进行。将云南瑞丽ＨＩＶ毒株的ｅｎｖＶ３－Ｖ５区序列与国际各亚型同源序列作比较，９０年和９３年ＨＩＶ毒株与Ｂ亚型的同源性均为最高。这表明云南瑞丽流行的ＨＩＶ毒株属国际Ｂ亚型。经分析发现，在９０年的１０个毒株的序列中，有８个是典型的Ｂ亚型序列，即Ｖ３环顶端的四肽是ＧＰＧＲ，占８０％；而在９３年的毒株中，该型序列只见于２１个样品中的１２个，比例下降到５７％。与此同时，Ｖ３环顶端四肽为ＧＰＧＱ的Ｂ亚型中的泰国基因型序列，则由９０年的１０％（１／１０）上升到９３年的２９％（６／２１）。进一步分析编码ＧＰＧＲ最末一个精氨酸密码子发现，ＣＧＡ与ＡＧＡ比例由９０年的１：７上升到９３年的５：７。由于ＣＧＡ比ＡＧＡ更接近编码谷氨酰胺（Ｑ）密码子ＣＡＡ，这种以ＧＰＧＱ为特征的泰国基因型Ｂ亚型毒株，在该地区还可能进一步增高。这些数据提示，当地流行的ＨＩＶ毒株Ｖ３环顶端的四肽在过去几年中由ＧＰＧＲ向ＧＰＧＱ漂移，其原因尚不清楚。
Dehong bordering on Myanma in Yunnan province is China’s only HIV epidemic region,where about 70% of the country’s total HIV infections were detected among local drug injecting users(IDUs).Blood samples were collected from the local HIV infected IDUs in 1990and 1993.HIV-1 env genes were amplified from uncultured PMC and cloned Sequencing wasconductal both manually and by using an automatic DNA sequencer(ABI,373A).HIV-1 subtype B viruses were found in all of the uncultured PMC samples according to their env V3 to V5 region.In comparision with the consensus sequence of international subgroups,the local HIV sequences from both 1990 and 1993 have the highest homolohy to subtype B.This is in agreement with our former report that the HIV-infected personspredominantly reacted with M3 peptide of North American HIV strains and much less to that of other regions. The more typical subtype B variants (all with a GPGR V3-tip tetrapeptide)constituted 8 of 10 samples(80%)in 1990,but only 12 of 21 samples(57%)in 1993.The proportion of subtypeB/Thai genotype B(with a consensus GPGQ motif)increased from 10%(1 of 10) in 1990 to 29%(6 of 21)in 1993.While among the samples with GPGR V3-tip,the ratio for the terminal arginine codon CGA to AGA also increased from 1:7 to 1993. Since CGA is closer to the codon CAA of glutamine than AGA,the proportion of Thai genotype Bvirus might further increase in the future. These data suggest that for unknown reasons there is a drift from GPGR to GPGQ of the tetrapeptide on the V3-loop tip of local HIV strainswith times.
出处
《病毒学报》
CAS
CSCD
北大核心
1994年第4期291-299,共9页
Chinese Journal of Virology
基金
"863"艾滋病毒分子生物学跟踪研究课题
