T103A变异MxA蛋白抑制水泡性口膜炎病毒复制的体外研究

目的研究T103A变异MxA蛋白抑制水疱性口膜炎病毒（VSV）复制活性。方法将野生型、T103A变异MxA蛋白表达载体和对照质粒分别瞬时转染Wish细胞，24h后VSV感染细胞，48h后用MTr法检测各组细胞增殖；另取Wish细胞转染上述3种质粒，转染24h加入VSV感染细胞，24h后收集细胞采用RT-PCR检测VSVmRNA水平；Western blot检测各组MxA蛋白表达。结果野生型、T103A变异MxA蛋白均在Wish细胞有较好表达；MTT检测结果提示T103A变异组细胞增殖数显著低于野生型组（P〈0．01）；RT—PCR结果显示T103A变异组VSVmRNA水平显著高于野生型组（P〈0．01），但与对照组比较差异无统计学意义（P〉0．05）。结论T103A变异MxA蛋白失去了抑制VSV复制活性。

In vitro Inhibition of VSV Replication by the T103A Mutant MxA Protein

Objective To investigate the antiviral activity of T103A mutant MxA protein in vesicular stomatitis virus （VSV） infected cells. Methods Wish cells were transfected with control vector or pcDNA3.1-MxA carrying the wild-type or T103A mutant MxA gene. Twenty-four hours after transfection, the cells were infected with VSV and the viability of the infected cells was determined By the MTT reduction method at 48 h after infction. Level of VSV mRNA was determined by RT-PCR at 24 h after VSV infection. Results Both wild-type MxA and T103A mutant proteins were expressed in infected cells. The viability of cells expressing T103A mutant proteins was markedly lower than the cells expressing the wild-type proteins （P〈0.01）. Similar to the control group, the level of VSV mRNA in T103A mutant protein expressing cells was markedly higher than the cells expressing the wild-type proteins （P〈0.01）. Conclusion T103A mutation is responsible for the lost of antiviral activity of the MxA protein.