中国部分地区HIV患者B′和B′/C亚型毒株tat第一外显子基因变异与HIV疾病进展关系的研究

目的 了解中国B’和B’／C亚型HIV／AIDS患者tat第一外显子的基因序列及其二级结构的特征和变异特点，探讨其与HIV-1感染疾病进展之间的关系。方法 从辽宁、吉林和云南省HIV-1感染者中选取病情呈缓慢进展的B’亚型感染者8例和B’／C亚型感染者5例，选择年龄、性别感染时间与前二者匹配的病情呈典型进展的B’亚型感染者26例和B’／C亚型感染者9例。采集外周静脉血，提取前病毒DNA，用巢式聚合酶链反应扩增HIV-1的tat基因，纯化后直接进行基因序列测定，序列编辑后翻译成氨基酸序列，进行氨基酸变异情况分析和二级结构预测。结果 B’和B’／C亚型缓慢进展者、典型进展者Tat第一外显子中发现多种氨基酸替换，但除A58T外均未显示出与病毒载量以及疾病进展的明确相关性。23N、31S、32Y、46F变异均显示出亚型特异性；Tat蛋白的二级结构未发现规律性变化。结论 中国HIV／AIDs患者tat第一外显子某些位点的基因变异，如A58T可能与病毒载量以及疾病进展有关，Tat蛋白的二级结构可能与HIV感染后的疾病进展无明显关系。

Study on the relationship between the polymorphisms and secondary structure of tat exon-1 gene and HIV/AIDS progress in subtype B'and B'/C

OBJECTIVE: To study the polymorphisms and secondary structure of human immunodeficiency virus (HIV-1) tat exon 1 among subtype B' and B'/C HIV-1 infected people in China and to explore the relationship between the polymorphism of tat exon 1 and the disease progression. METHODS: 8 subtype B' and 5 B'/C HIV-1 infected patients with slow disease progression were selected from Liaoning, Jilin and Yunnan province. 26 subtype B' and 9 B'/C HIV-1 infected patients with similar sex, age but with typical disease progression were selected. Provirus was extracted from the whole blood. The gene sequences of the Tat exon 1 were amplified by nest-polymerase chain reaction (nest-PCR). Products were purified and sequenced directly. The sequences were aligned, translated, amino acid substitution were analyzed and secondary structures were predicted. RESULTS: Many amino acid substitution could be found in the exon 1 of Tat in HIV-1 subtype B' and B'/C recombinant strain infected persons with different disease progression except A58T,none of them showed definitely relationship with HIV viral load and disease progression. 23N, 31S, 32Y and 46F were subtype-specific substitutions. No characteristic secondary structure of exon 1 of Tat was found. CONCLUSION: Some of the mutations of tat exon 1 might be related to HIV viral load and disease progression. However, there was no relationship found between the secondary structure of Tat protein and the disease progression.