Functional study of the different haplotypes cDNA in the coding region of CⅡTA gene

Objective To study the function of 4 different haplotypes cDNA which are constructed by two non-homonymy single nueleotide polymorphism (SNP) sites C19170G (Leu45Val) and C30799G (Ala500Gly) in the coding region of human CⅡTA gene. Methods HeLa cells were transfeeted with eu-karyotic expression vectors containing four different haplotypes cDNA. C Ⅱ TA mRNA and HLA classⅡanti-gen (HLA-DR, DP, DQ) were respectively detected by RT-PCR and indirect cell immunofluoreseence tech-nique in the untransfected and transfeeted with four eukaryotic expression vectors and empty vectors HeLa cells. The quantity of HLA classⅡ antigen were analyzed by flow eytometry. Results No expression of CⅡTA mRNA and HLA class Ⅱ antigen were observed on original HeLa cells and empty vector transfected cells. CⅡTA mRNA expression was emerged, and the expression of HLA class Ⅱ antigen were observed in the HeLa cells transfected with eukaryotic expression vectors containing four different haplotypes cDNA. And there were not significantly different with the levels of HLA class Ⅱ antigen expression among HeLa cells transfected with eukaryotic expression vectors containing four different haplotypes cDNA ( P > 0.05 ). Con-dusion The SNP of Chinese at the sites C19170G(Leu45Val) and C30799G(Ala500Gly) in the coding site of C Ⅱ TA gene did not influence capability of CⅡTA trans-aetivating HLA class Ⅱgene expression.     

Functional study of the different haplotypes cDNA in the coding region of CⅡTA gene

Objective To study the function of 4 different haplotypes cDNA which are constructed by two non-homonymy single nueleotide polymorphism (SNP) sites C19170G (Leu45Val) and C30799G (Ala500Gly) in the coding region of human CⅡTA gene. Methods HeLa cells were transfeeted with eu-karyotic expression vectors containing four different haplotypes cDNA. C Ⅱ TA mRNA and HLA classⅡanti-gen (HLA-DR, DP, DQ) were respectively detected by RT-PCR and indirect cell immunofluoreseence tech-nique in the untransfected and transfeeted with four eukaryotic expression vectors and empty vectors HeLa cells. The quantity of HLA classⅡ antigen were analyzed by flow eytometry. Results No expression of CⅡTA mRNA and HLA class Ⅱ antigen were observed on original HeLa cells and empty vector transfected cells. CⅡTA mRNA expression was emerged, and the expression of HLA class Ⅱ antigen were observed in the HeLa cells transfected with eukaryotic expression vectors containing four different haplotypes cDNA. And there were not significantly different with the levels of HLA class Ⅱ antigen expression among HeLa cells transfected with eukaryotic expression vectors containing four different haplotypes cDNA ( P > 0.05 ). Con-dusion The SNP of Chinese at the sites C19170G(Leu45Val) and C30799G(Ala500Gly) in the coding site of C Ⅱ TA gene did not influence capability of CⅡTA trans-aetivating HLA class Ⅱgene expression.     

Functional study of the different haplotypes cDNA in the coding region of CⅡTA gene

Objective To study the function of 4 different haplotypes cDNA which are constructed by two non-homonymy single nueleotide polymorphism (SNP) sites C19170G (Leu45Val) and C30799G (Ala500Gly) in the coding region of human CⅡTA gene. Methods HeLa cells were transfeeted with eu-karyotic expression vectors containing four different haplotypes cDNA. C Ⅱ TA mRNA and HLA classⅡanti-gen (HLA-DR, DP, DQ) were respectively detected by RT-PCR and indirect cell immunofluoreseence tech-nique in the untransfected and transfeeted with four eukaryotic expression vectors and empty vectors HeLa cells. The quantity of HLA classⅡ antigen were analyzed by flow eytometry. Results No expression of CⅡTA mRNA and HLA class Ⅱ antigen were observed on original HeLa cells and empty vector transfected cells. CⅡTA mRNA expression was emerged, and the expression of HLA class Ⅱ antigen were observed in the HeLa cells transfected with eukaryotic expression vectors containing four different haplotypes cDNA. And there were not significantly different with the levels of HLA class Ⅱ antigen expression among HeLa cells transfected with eukaryotic expression vectors containing four different haplotypes cDNA ( P > 0.05 ). Con-dusion The SNP of Chinese at the sites C19170G(Leu45Val) and C30799G(Ala500Gly) in the coding site of C Ⅱ TA gene did not influence capability of CⅡTA trans-aetivating HLA class Ⅱgene expression.     

Functional study of the different haplotypes cDNA in the coding region of CⅡTA gene

Objective To study the function of 4 different haplotypes cDNA which are constructed by two non-homonymy single nueleotide polymorphism (SNP) sites C19170G (Leu45Val) and C30799G (Ala500Gly) in the coding region of human CⅡTA gene. Methods HeLa cells were transfeeted with eu-karyotic expression vectors containing four different haplotypes cDNA. C Ⅱ TA mRNA and HLA classⅡanti-gen (HLA-DR, DP, DQ) were respectively detected by RT-PCR and indirect cell immunofluoreseence tech-nique in the untransfected and transfeeted with four eukaryotic expression vectors and empty vectors HeLa cells. The quantity of HLA classⅡ antigen were analyzed by flow eytometry. Results No expression of CⅡTA mRNA and HLA class Ⅱ antigen were observed on original HeLa cells and empty vector transfected cells. CⅡTA mRNA expression was emerged, and the expression of HLA class Ⅱ antigen were observed in the HeLa cells transfected with eukaryotic expression vectors containing four different haplotypes cDNA. And there were not significantly different with the levels of HLA class Ⅱ antigen expression among HeLa cells transfected with eukaryotic expression vectors containing four different haplotypes cDNA ( P > 0.05 ). Con-dusion The SNP of Chinese at the sites C19170G(Leu45Val) and C30799G(Ala500Gly) in the coding site of C Ⅱ TA gene did not influence capability of CⅡTA trans-aetivating HLA class Ⅱgene expression.     

Functional study of the different haplotypes cDNA in the coding region of CⅡTA gene

Objective To study the function of 4 different haplotypes cDNA which are constructed by two non-homonymy single nueleotide polymorphism (SNP) sites C19170G (Leu45Val) and C30799G (Ala500Gly) in the coding region of human CⅡTA gene. Methods HeLa cells were transfeeted with eu-karyotic expression vectors containing four different haplotypes cDNA. C Ⅱ TA mRNA and HLA classⅡanti-gen (HLA-DR, DP, DQ) were respectively detected by RT-PCR and indirect cell immunofluoreseence tech-nique in the untransfected and transfeeted with four eukaryotic expression vectors and empty vectors HeLa cells. The quantity of HLA classⅡ antigen were analyzed by flow eytometry. Results No expression of CⅡTA mRNA and HLA class Ⅱ antigen were observed on original HeLa cells and empty vector transfected cells. CⅡTA mRNA expression was emerged, and the expression of HLA class Ⅱ antigen were observed in the HeLa cells transfected with eukaryotic expression vectors containing four different haplotypes cDNA. And there were not significantly different with the levels of HLA class Ⅱ antigen expression among HeLa cells transfected with eukaryotic expression vectors containing four different haplotypes cDNA ( P > 0.05 ). Con-dusion The SNP of Chinese at the sites C19170G(Leu45Val) and C30799G(Ala500Gly) in the coding site of C Ⅱ TA gene did not influence capability of CⅡTA trans-aetivating HLA class Ⅱgene expression.     

Functional study of the different haplotypes cDNA in the coding region of CⅡTA gene

Objective To study the function of 4 different haplotypes cDNA which are constructed by two non-homonymy single nueleotide polymorphism (SNP) sites C19170G (Leu45Val) and C30799G (Ala500Gly) in the coding region of human CⅡTA gene. Methods HeLa cells were transfeeted with eu-karyotic expression vectors containing four different haplotypes cDNA. C Ⅱ TA mRNA and HLA classⅡanti-gen (HLA-DR, DP, DQ) were respectively detected by RT-PCR and indirect cell immunofluoreseence tech-nique in the untransfected and transfeeted with four eukaryotic expression vectors and empty vectors HeLa cells. The quantity of HLA classⅡ antigen were analyzed by flow eytometry. Results No expression of CⅡTA mRNA and HLA class Ⅱ antigen were observed on original HeLa cells and empty vector transfected cells. CⅡTA mRNA expression was emerged, and the expression of HLA class Ⅱ antigen were observed in the HeLa cells transfected with eukaryotic expression vectors containing four different haplotypes cDNA. And there were not significantly different with the levels of HLA class Ⅱ antigen expression among HeLa cells transfected with eukaryotic expression vectors containing four different haplotypes cDNA ( P > 0.05 ). Con-dusion The SNP of Chinese at the sites C19170G(Leu45Val) and C30799G(Ala500Gly) in the coding site of C Ⅱ TA gene did not influence capability of CⅡTA trans-aetivating HLA class Ⅱgene expression.     

Functional study of the different haplotypes cDNA in the coding region of CⅡTA gene

Objective To study the function of 4 different haplotypes cDNA which are constructed by two non-homonymy single nueleotide polymorphism (SNP) sites C19170G (Leu45Val) and C30799G (Ala500Gly) in the coding region of human CⅡTA gene. Methods HeLa cells were transfeeted with eu-karyotic expression vectors containing four different haplotypes cDNA. C Ⅱ TA mRNA and HLA classⅡanti-gen (HLA-DR, DP, DQ) were respectively detected by RT-PCR and indirect cell immunofluoreseence tech-nique in the untransfected and transfeeted with four eukaryotic expression vectors and empty vectors HeLa cells. The quantity of HLA classⅡ antigen were analyzed by flow eytometry. Results No expression of CⅡTA mRNA and HLA class Ⅱ antigen were observed on original HeLa cells and empty vector transfected cells. CⅡTA mRNA expression was emerged, and the expression of HLA class Ⅱ antigen were observed in the HeLa cells transfected with eukaryotic expression vectors containing four different haplotypes cDNA. And there were not significantly different with the levels of HLA class Ⅱ antigen expression among HeLa cells transfected with eukaryotic expression vectors containing four different haplotypes cDNA ( P > 0.05 ). Con-dusion The SNP of Chinese at the sites C19170G(Leu45Val) and C30799G(Ala500Gly) in the coding site of C Ⅱ TA gene did not influence capability of CⅡTA trans-aetivating HLA class Ⅱgene expression.     

Functional study of the different haplotypes cDNA in the coding region of CⅡTA gene

Objective To study the function of 4 different haplotypes cDNA which are constructed by two non-homonymy single nueleotide polymorphism (SNP) sites C19170G (Leu45Val) and C30799G (Ala500Gly) in the coding region of human CⅡTA gene. Methods HeLa cells were transfeeted with eu-karyotic expression vectors containing four different haplotypes cDNA. C Ⅱ TA mRNA and HLA classⅡanti-gen (HLA-DR, DP, DQ) were respectively detected by RT-PCR and indirect cell immunofluoreseence tech-nique in the untransfected and transfeeted with four eukaryotic expression vectors and empty vectors HeLa cells. The quantity of HLA classⅡ antigen were analyzed by flow eytometry. Results No expression of CⅡTA mRNA and HLA class Ⅱ antigen were observed on original HeLa cells and empty vector transfected cells. CⅡTA mRNA expression was emerged, and the expression of HLA class Ⅱ antigen were observed in the HeLa cells transfected with eukaryotic expression vectors containing four different haplotypes cDNA. And there were not significantly different with the levels of HLA class Ⅱ antigen expression among HeLa cells transfected with eukaryotic expression vectors containing four different haplotypes cDNA ( P > 0.05 ). Con-dusion The SNP of Chinese at the sites C19170G(Leu45Val) and C30799G(Ala500Gly) in the coding site of C Ⅱ TA gene did not influence capability of CⅡTA trans-aetivating HLA class Ⅱgene expression.     

Functional study of the different haplotypes cDNA in the coding region of CⅡTA gene

Objective To study the function of 4 different haplotypes cDNA which are constructed by two non-homonymy single nueleotide polymorphism (SNP) sites C19170G (Leu45Val) and C30799G (Ala500Gly) in the coding region of human CⅡTA gene. Methods HeLa cells were transfeeted with eu-karyotic expression vectors containing four different haplotypes cDNA. C Ⅱ TA mRNA and HLA classⅡanti-gen (HLA-DR, DP, DQ) were respectively detected by RT-PCR and indirect cell immunofluoreseence tech-nique in the untransfected and transfeeted with four eukaryotic expression vectors and empty vectors HeLa cells. The quantity of HLA classⅡ antigen were analyzed by flow eytometry. Results No expression of CⅡTA mRNA and HLA class Ⅱ antigen were observed on original HeLa cells and empty vector transfected cells. CⅡTA mRNA expression was emerged, and the expression of HLA class Ⅱ antigen were observed in the HeLa cells transfected with eukaryotic expression vectors containing four different haplotypes cDNA. And there were not significantly different with the levels of HLA class Ⅱ antigen expression among HeLa cells transfected with eukaryotic expression vectors containing four different haplotypes cDNA ( P > 0.05 ). Con-dusion The SNP of Chinese at the sites C19170G(Leu45Val) and C30799G(Ala500Gly) in the coding site of C Ⅱ TA gene did not influence capability of CⅡTA trans-aetivating HLA class Ⅱgene expression.     

CⅡTA基因编码区不同单倍型cDNA的功能研究

目的 研究MHCⅡ类反式激活因子(cⅡTA)基因编码区非同义单核苷酸多态性(SNP)位点C19170G(Leu45Val)和C30799G(Ala500Gly)构成的4种不同单倍型cDNA的功能.方法 将4种不同单倍型的真核表达载体和卒载体分别转染至HeLa细胞.用RT-PCR和间接细胞免疫荧光技术检测未经转染的HeLa细胞、转染4种真核表达载体及卒载体的HeLa细胞cⅡTA mRNA与3种HLAⅡ类分子(HLA-DR、DP、DQ)的表达,并用流式细胞技术对其表达的3种HLAⅡ类蛋白进行定量分析.结果 未经转染和转染空载体的HeLa细胞均尤CⅡTA mRNA和3种HLAⅡ类分子的表达,而转染4种不同单倍型真核表达载体的HeLa细胞均出现CⅡTA mRNA表达,并表达3种HLAⅡ类分子.证实了转染4种不同单倍型真核表达载体后的HeLa细胞3种HLAⅡ类分子表达水平差异无统计学意义(P均>0.05).结论 中国人CⅡTA基因编码区这两个SNP位点的多态性(2个位点氨基酸的改变)不影响CⅡTA反式激活HLAⅡ类基因表达的能力.     

088 MHCⅡ类分子反式激活因子（CⅡTA）的研究进展

ＭＨＣⅡ分子反式激活蛋白（ＣＴＡ，ｃｌａｓｓⅡ 的发现是近年来国际免疫学研究的一项重大突破，ＣⅡＴＡ及其突变体在免疫调节和免疫治疗中具有诱人前景。本文对ＣⅡＴＡ的结构，功能及其反式激活ＭＨＣⅡ类分子的机制作一综述，并对ＣⅡＴＡ及其突一的应用前景作一简要介绍。     

CⅡTA锤头状核酶的克隆及其体外活性

通过CⅡTA核酶抑制HeLa细胞表面MHC Ⅱ类分子的表达.设计并合成针对人类CⅡTA的核酶Rz464,通过体外转录和切割实验鉴定其活性.将Rz464亚克隆到真核表达载体pIRES2-EGFP(pRz464),并稳定转染HeLa细胞株,流式细胞术检测MHC Ⅱ类抗原表达,RT-PCR检测CⅡTA mRNA水平.结果表明,Rz464与CⅡTA靶序列体外切割产物电泳见预期切割条带.pRz464+HeLa细胞与对照组比较,HLA-DR、DP、DQ抗原诱导型表达分别降低了79.21%、90.31%及48.30%;同时CⅡTA的诱导型mRNA含量明显减少.Rz464通过切割CⅡTA mRNA,进而阻止了后者调控的MHC Ⅱ类分子的表达.     

CⅡTA M1-RNA对MHCⅡ类分子表达的抑制作用

目的探讨MHCⅡ类分子转录激活因子（CⅡTA）的M1-RNA对细胞表面MHCⅡ类分子表达的抑制。方法M1-RNA是核糖核酸酶P的催化活性单位，设计并克隆针对CⅡTA第452、629位点的M1-RNA（分别为M1-452-GS、M1-629-GS）及其相应的CⅡTA靶基因，分别插入pUC19、pGEM-7zf（＋）载体，进行细胞外切割活性筛选。将细胞外切割作甩明显的M1-629-GS亚克隆入psNAV载体（psNAV-M1-629-GS，pA629）并稳定转染ECV304细胞株，流式细胞术检测经典的MHCⅡ（HLA-DR、-DP、-DQ）类抗原表达，RT-PCR检测CⅡTA的mRNA水平。结果pA629阳性ECV304细胞株与对照组比较，HLA-DR、-DP抗原表达分别降低了89．21％及92．31％；同时CⅡTA的mRNA含量降低（P〈0．05）。结论CⅡTA的M1-RNA（M1-629-GS）降低了自身mRNA含量，从而阻止其调控的MHCⅡ类分子的表达。     

CⅡTA对MHCⅠ/Ⅱ类分子的反式激活作用

CⅡTA(MHCclassⅡtransactivator)指MHCⅡ类分子反式激活因子 ,与MHCⅠ /Ⅱ类基因及各种抗原递呈相关基因的表达密切相关 ,涉及的机理较为复杂。本文拟就CⅡTA对MHCⅠ /Ⅱ类分子的反式激活机理作一综述     

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

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MHCⅡ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CⅡTA-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MHCⅡ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-CⅡTAm；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-7的上调，同时抑制这些细胞上诱导型和组成型MHCⅡ类分子的表达。结论：Ad-pIV-CⅡTAm重组腺病毒是一种WN-γ调控型表达载体，可有效地抑制受感染细胞上MHCⅡ类分子的表达。     

腺病毒介导CⅡTA突变体基因转移抑制MHCⅡ类分子表达的体外研究

目的:构建携带小鼠MHCⅡ类分子反式激活因子(MHC class Ⅱ molecule transactivator,CⅡTA)突变体基因的腺病毒,并观察腺病毒介导该基因的表达情况以及表达产物的体外功能.方法:采用常规分子生物学方法从IFN-γ诱导后的BALB/c小鼠腹腔巨噬细胞中获得Ⅳ型CIITAcDNA;利用重叠延伸PCR法构建CIITA突变体基因,并克隆入表达载体pIRES;采用pAdEasy-1系统获得具有感染能力的、携带CIITA突变体基因的缺陷型重组腺病毒(Ad-CIITAm)和空载对照病毒(Ad-GFP),并经大量扩增、纯化及滴度测定;将Ad-CⅡTAm和Ad-GFP分别感染HeLa细胞和Raji细胞,流式细胞术观察对诱导型和组成型HLA-DR分子表达的影响.结果:成功克隆了小鼠CⅡTA突变体基因,并构建了携带小鼠CⅡTA突变体基因的重组腺病毒Ad-CⅡTAm;经流式细胞术证实感染Ad-CⅡTAm的Hela和Raji细胞较感染Ad-GFP的细胞,其表面HLA-DR分子的表达均受到明显的抑制.结论:本实验证实了重组腺病毒介导表达的小鼠CⅡTA突变体在体外能够有效地抑制MHCⅡ类分子的表达.     

CIITA锤头状核酶的克隆及其体外活性

通过CIITA核酶抑制HeLa细胞表面MHCⅡ类分子的表达。设计并合成针对人类CIITA的核酶Rz464,通过体外转录和切割实验鉴定其活性。将Rz464亚克隆到真核表达载体pIRES2-EGFP(pRz464),并稳定转染HeLa细胞株,流式细胞术检测MHCⅡ类抗原表达,RT-PCR检测CIITA mRNA水平。结果表明,Rz464与CIITA靶序列体外切割产物电泳见预期切割条带。pRz464~+HeLa细胞与对照组比较,HLA-DR、DP、DQ抗原诱导型表达分别降低了79.21%、90.31%及48.30%;同时CIITA的诱导型mRNA含量明显减少。Rz464通过切割CIITA mRNA,进而阻止了后者调控的MHCⅡ类分子的表达。