摘要
经套式聚合酶链反应(nested-PCR)对17份1995年初采集于云南瑞丽市人免疫缺陷病毒1型(HIV-1)阳性静脉吸毒者外周血单核细胞(PBMCs)的核酸样品进行扩增,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。结果表明,17份样品中存在B和C两种亚型的HIV-1毒株序列,其亚型内的基因离散率分别为58%和22%,与A-E参考亚型及部分B和C亚型代表株序列相比较,属B亚型的12个毒株与包括泰国、缅甸及云南瑞丽代表株yn289在内的B亚型毒株序列十分接近,基因离散率在44%~49%的范围内;属C亚型的5个毒株则与主要代表印度C亚型毒株的共享序列ccon及瑞丽C亚型代表毒株yn272十分相似,其基因离散率均为19%。以上数据进一步确认我们的结论,即HIV-1在瑞丽的流行以B亚型毒株为主、C亚型的传人和流行时间较短。对B亚型毒株V3环序列的分析还发现,位于V3环顶端的四肽序中GPGQ占50%,GPGR则仅占25%,且编码其精氨酸(R)的密码子均为CGA而不是AGA。此结果与我们根据早期瑞丽HIV-1毒株序列研究结果得出的推测?
DNA fragments of HIV-1 env gene were amplified by nested-PCR from 17 uncultured peripheral blood mononuclear cells (PBMCs) obtained from HIV-1 seropositive intravenous drug users (IDUs) in Ruili city of Yunnan Province. The C2-V3 region (about 450 bp) of them were sequenced. Sequence analysis showed that there exists two HIV-1 subtypes, B and C, with 5.8% and 2.2% gene divergence inside each subtype. The 12 subtype B strains, were closely related to those found in Thailand, Myanma and Ruili city of Yunnan, and the nucleotide sequence divergence between them ranged from 4.4% to 4.9%; meanwhile, the 5 subtype C strains were most close to those found in lndia as well as Ruili city, all with a genetic distance of 1.9%. The small divergence among Ruili HIV-1 subtype C strains suggests a recent epidemic. The analysis of V3 loop amino sequence of 12 subtype B HIV-1 reveals that V3-tip motif of 6 samples (50%) is GPGQ and that of 3 samples (25%) is GPGR. In addition, the codon of arginine (R) of all the strains is CGA instead of AGA. This result is in accordance with our previous hypothesis that there is a drift in vivo from GPGR to GPGQ motif on the tip of V3-loop of HIV-1 subtype B strain in this area with the elapse of time.
出处
《中华实验和临床病毒学杂志》
CAS
CSCD
1997年第1期8-12,共5页
Chinese Journal of Experimental and Clinical Virology
关键词
人免疫缺陷病毒
基因转变
序列分析
Human immunodeficiency virus type 1
Gene variation
Sequencing