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

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

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。

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.