摘要
使用ＰＣＲ对２１份采集于１９９５年中的云南陇川县ＨＩＶ－１阳性静脉吸毒者外周血单个核细胞（ＰＢＭＣｓ）样品进行扩增，从１７份样品中获得了ＨＩＶ－１膜蛋白（ｅｎｖ）基因的核酸片段，并对其Ｃ２－Ｖ３及邻区４５０个核苷酸序列进行了测定和分析。研究结果表明，１７份陇川样品中存在Ｂ和Ｃ两种亚型的ＨＩＶ－１毒株序列，各亚型内的基因离散率分别为４．７％和３．３％。与Ａ～Ｅ参考亚型及部分Ｂ和Ｃ亚型代表株序列相比较，属陇川Ｂ亚型的１４个毒株与包括泰国、缅甸及云南瑞丽在内的Ｂ亚型毒株序列十分接近，基因离散率在３．９％～４．５％的范围内；属陇川Ｃ亚型的３个毒株则与代表印度毒株的Ｃ亚型共享序列及瑞丽Ｃ亚型毒株序列十分相似，其基因离散率均为２．５％。以上数据提示，ＨＩＶ－１在陇川的流行时间不长，且Ｂ和Ｃ亚型毒株的传入时间相差１年左右。对Ｂ亚型毒株Ｖ３环序列的分析还发现，位于Ｖ３环顶端的四肽序列中ＧＰＧＱ占６４．３％，ＧＰＧＲ则仅占２８．６％，且编码其精氨酸（Ｒ）的密码子均为ＣＧＡ而不是ＡＧＡ。此结果与作者根据早期瑞丽ＨＩＶ－１毒株序列研究结果得出的推测相吻合。
Seventeen DNA fragments of HIV 1 env gene were amplified by PCR from uncultured peripheral blood mononuclear cells (PBMCs) obtained from 21 HIV 1 sero positive injecting drug users(IDUs) in Longchuan county of Yunnan province.The C2 V3 region(about 450 bp) of them were sequenced.Sequence analysis showed that there were two HIV 1 subtypes,B and C,with 4 7% and 3 3% gene divergence inside each subtype,in Longchuan.The 14 subtype B strains,after compared with sequences of several reference HIV 1 strains,were closely related to those found in Thailand,Myanma and Ruili county of Yunnan,and the nucleotide sequence divergence between them ranged from 3 9% to 4 5%.Meanwhile,the 3 subtype C strains were most close to those found in lndia as well as Ruili county of Yunnan,and their nucleotide sequence divergence were both 2 5%.The low level of sequence divergence among Longchuan HIV 1 subtype B and C strains suggests a recent epidemic of each virus,and about 1 year′s delaying of introduction of subtype C into IDUs population compared with that of subtype B.In addition,analysis of V3 loop amino acid sequence of 14 subtype B HIV 1 revealed that 9 samples (64 3%) possed GPGQ V3 tip motif and 3 GPGR motif,whose codon of arginine (R) were all CGA instead of AGA.This result is in accordance with our previous hypothesis that there is a drift from GPGR to GPGQ motif on the V3 loop tip of HIV 1 subtype B strain with the lapse of time in this area.
出处
《中华微生物学和免疫学杂志》
CAS
CSCD
北大核心
1997年第1期1-6,共6页
Chinese Journal of Microbiology and Immunology
基金
"863"艾滋病毒分子生物学跟踪研究课题基金
