中国艾滋病病毒1型流行毒株V_3环序列变异性的研究

Study on Sequence Variation in the V_3 Loop of HIV-1 Strains Prevalent in China

目的 研究中国艾滋病病毒1型(HIV-1)毒株V3环序列的变异性。方法 对中国1996～2000年491例HIV-1感染者env基因C2-V3区经聚合酶链反应(PCR)扩增并测序,测得的序列经DNA软件编辑后,用Wisconsin公司GCG软件包进行分析。结果 从核酸序列可以看出,V3环的核苷酸存在着点突变和基因的漂移。各亚型流行株V3顶端的四肽特征主要为:GPGQ 72.6％,GPGR 13％,GPGK 7.6％,其它形式6.7％。在V3环氨基酸序列11、25位点未同时出现带正电荷的氨基酸。基因离散率的分析表明呈现逐年递增趋势。结论 中国V3环顶端四肽序列主要为GPGQ,从1990的10％、1993年的29％上升到2000年的72.6％。而GPGR则从1990年的80％、1993年的57％下降到2000年的13％。更加证明了在中国存在着HIV-1毒株V3区顶端四肽由GPGR向GPGQ漂移的现象。从V3环序列的高度变异性分析表明中国正处于HIV快速流行期。

Objective To study sequence variation of V3 loop of HIV-1 strains prevalent in China. Methods Sequences of the env C2-V3 region of 491 HIV-positive samples collated from January 1996 to December 2000 were analyzed. Wisconsin Software package or Genetics Computer Group(GCG)was applied. Results The V3 loop motif was variable.Out of these samples, the V3 loop terra peptide GPGQ accounted for about 72.6 %, GPGR-13 % . and GPGK -7.6%. Other V3 loop tetra peptide forms were 6.7% al together. At the llth and 25th sites no positive charge appeared in aminoacids simultaneously.Furthermore, the percentage of samples with tetra peptide GPGQ were increasing from 10% in 1990 and 29% in 1993 to 72.6% in 2000, while the percentage of samples with tetra peptide GPGR were decreasing from 80 % in 1990 and 57 % in 1993 to 13 % in 2000. The genetic distances in Ci-V3 region were increasing over the year. Conclusions This study further reveals that there exist drift from tetra peptide GPGR to GPGQ in Vg loop. The increase in C2 - V3 sequence distances over the year shows a rapid expansion of HIV infections in China.