小鼠pIV启动子调控CⅡTA突变体重组腺病毒表达选择性抑制MHC Ⅱ类分子的表达  

The selective suppression of MHC Ⅱ molecule expression by recombinant adenovirus with mouse pIV promoter-regulated CⅡTA mutant

作　　者：龙宪连[1] 管政[1] 张军[1] 方超平[1] 张薇薇[1] 张倩[1] 沈茜[1] 

机构地区：[1]第二军医大学附属长海医院实验诊断科,上海200433

出　　处：《中国免疫学杂志》2008年第9期781-785,共5页Chinese Journal of Immunology

基　　金：国家自然科学基金(30500501);上海市科委联合利华研究与发展基金(200305)资助项目

摘　　要：目的:观察受CⅡTA-pIV启动子驱动的MHCⅡ类分子反式激活因子突变体(CⅡTAm)重组腺病毒对MHC Ⅱ类分子表达的选择性抑制作用,并探讨其相关机制。方法:构建了N-端酸性氨基酸区缺失了118aa的CⅡTA突变体及其CⅡ TA-pIV启动子驱动的重组腺病毒Ad-pIV-CⅡTAm,将Ad-pIV-CⅡTAm或对照腺病毒Ad-GFP感染小鼠内皮细胞株SVEC细胞和转染巨噬细胞株J774细胞,并以IFN-γ刺激。用RT-PCR检测野生型和突变型CⅡTA mRNA的表达,用流式细胞术检测MHC Ⅱ类分子在细胞表面的表达。结果:成功构建CⅡTA-pIV启动子调控下的CⅡTA突变体基因重组腺病毒表达载体Ad-pIV-CⅡ TAm;该腺病毒介导的CⅡTA突变体mRNA在SVEC和J774细胞内的表达受到IFN-γ的上调,同时抑制这些细胞上诱导型和组成型MHC Ⅱ类分子的表达。结论:Ad-pIV-CⅡTAm重组腺病毒是一种IFN-γ调控型表达载体,可有效地抑制受感染细胞上 MHC Ⅱ类分子的表达。Objective： To observe the selective suppression effect on the MHC Ⅱ molecule expression by pIV promoter-controlled recombinant adenovirus containing MHC class Ⅱ transactivator mutant （C Ⅱ TAm） ,and to explore the concerned mechanisms.Methods：A C II TA mutant lacking 118aa in the N-terminal acidic amino acid region and a pIV promoter-controlled recombinant adenovirus containing this mutant （Ad-pIV-C Ⅱ TAm） were constructed. Cell lines SVEC and J774 were infected or transfected by Ad-plV-C Ⅱ TAm or the control recombi- nant adenovirus Ad-GFP, and then were stimulated with IFN-γ. RT-PCR was used to determine the wild-type C Ⅱ TA and C Ⅱ TA mutant mRNA expression,and flow cytornetry was used to determine MHC Ⅱ molecule expression on these cells.Results：Recombinant adenovirus （Ad-pIV- C Ⅱ TAm） containing C Ⅱ TA-plV promoter and C Ⅱ TA mutant was constructed successfully. Adenovirus-mediated C Ⅱ TA mutant mRNA expression was induced strongly by IFN-γ in SVEC and J774 cells. The expression of recombinant adenovirus-mediated C ⅡTA mutant significantly repressed the constitutive and inducible expression of MHC Ⅱ molecules on these cells. Conclusion： Ad-plV-C Ⅱ TAm is an IFN-γ -responsive expression vector, and can significantly inhibit the expression of MHC Ⅱ molecules on the infected cells.

关 键 词：MHCⅡ类分子反式激活因子突变体 pIV启动子 腺病毒科 MHC Ⅱ类分子 

分 类 号：R392[医药卫生—免疫学]