人免疫缺陷病毒1型TAT突变蛋白及反义TAT RNA对TAT反式激活作用的抑制

INHIBITION EFFECT OF ANTISENSE TAT AND TAT MUTANT ON TRANSACTIVATION OF HIV-1 TAT PROTEIN

Ｔａｔ（Ｔｒａｎｓａｃｔｉｖａｔｏｒ）是人免疫缺陷病毒（ＨＩＶ）基因组编码的反式激活因子，突变分析表明它含有几个重要的功能域。为寻找控制ＨＩＶ复制的途径，构建了以ＨＩＶ－１ＬＴＲ（－１５８－＋８０）为启动子的ＴａｔｃＤＮＡ全长反义表达质粒ｐＡＳ－Ｔａｔ，并用已经构建的以ＨＩＶＬＴＲ－１５８到＋８０为启动子，具有不同突变点的突变Ｔａｔ基因表达质粒，以荧光酶基因为报告基因，共转染Ｊｕｒｋａｔ细胞，结果发现无论是反义Ｔａｔ表达质粒还是突变Ｔａｔ表达质粒，在瞬时转染体系中均能不同程度地抑制Ｔａｔ的活性，其中以ｐＭ５（５２位Ａｒｇ由Ｌｅｕ替代）和反义ＴａｔＲＮＡ的抑制效果最好。结果说明。

The Tat protein of the human immunodeficiency virus type 1 (HIV-1) is necessary for efficient viral gene expression.By means of mutational analysis,several domains of the Tat protein that are required for complete activation of HIV-1 gene expression have been defined.In order to find ways of controlling HIV replication,an expression vector was engineered to express antisense HIV-1 Tat cDNA(pAS-Tat).Mutant Tat expression vectors driven by HIV-1 LTR from -158 to +80 fragment,had also been constructed.In this work,both the AS Tat and the Tat mutants inhibited the transactivation of Tat when assayed for transient expression in Jurkat cells cotransfected with an expression vector with luciferase(Luc) driven by the HIV-1 LTR(-158 to +80) as the reporter gene and pS-Tat,a wild-type Tat expression vector directed by HIV-1 LTR.Maximum inhibition occurred with the construct of pM5 which had Arg 52 substituted for Leu.These results suggest that AS Tat or Tat mutants can be used in further studies on the treatment of HIV-1 infection.