hLMO4基因重组质粒的构建及蛋白表达和定位

目的构建hLMO4真核表达载体并证实融合蛋白在细胞内表达及定位。方法提取人乳腺癌MCF-7细胞的mRNA,反转录为cDNA。PCR扩增hLMO4全长编码基因,亚克隆至pCDNA3.1-myc-hisA表达载体中。将构建的重组质粒测序并转染到胃癌细胞BGC823中,提取细胞蛋白进行Western blot检测。利用共聚焦激光扫描显微镜观察pEGFP-LMO4在乳腺癌MCF-7细胞内定位。结果hLMO4全长基因序列克隆到了真核表达载体pCDNA3.1-myc-hisA中,酶切鉴定片段为500bp。Western blot检测到了融合蛋白表达,分子量约为23KD。pEGFP-LMO4在乳腺癌MCF-7细胞内定位以细胞核为主,在细胞浆内少量表达。结论成功的构建了hLMO4全长基因真核表达载体,pEGFP-LMO4蛋白定位于乳腺癌细胞质和核内。     

N端标记GFP-TFF3蛋白在非洲绿猴肾成纤维细胞表达和定位

目的构建pEGFP-N1-TFF3融合蛋白表达载体,并检测其在非洲绿猴肾成纤维细胞(COS7细胞)内的表达和定位。方法提取HT29细胞的mRNA,反转录为cDNA;以此为模板PCR扩增hTFF3(286bp-462bp)基因;通过EcoRⅠ和XhoⅠ双酶切位点将hTFF3基因定向插入真核表达载体pEGFP-N1中;将构建的重组质粒测序成功后,转染至人肾细胞(HEK293细胞)中,荧光显微镜观察GFP-TFF3融合蛋白的表达,并提取蛋白进行Western Blot检测;利用激光扫描共聚焦显微镜观察GFP-TFF3融合蛋白在COS7细胞内的定位情况。结果酶切及测序结果证明hTFF3基因成功克隆至真核表达载体pEGFP-N1中,Western Blot检测结果显示其融合蛋白分子量约为34kDa,激光扫描共聚焦显微镜观察结果显示GFP-TFF3融合蛋白在COS7细胞内定位以细胞核为主,在细胞质内少量表达。结论成功构建了pEGFP-N1-TFF3真核表达载体,GFP-TFF3蛋白定位于COS7的细胞核和细胞质中。     

包装细胞系及其在基因治疗研究中的应用

以逆转录病毒作载体的基因转移系统是基因治疗最基本的手段之一包装细胞系的构建是这一系统的重大突破它的主要特性是能将重组逆转录病毒载体包装成具一次感染性的缺失性病毒粒子,以此感染靶细胞,即能将外源基因稳定地整合到靶细胞的基因组上。通过改良,得到了能产生具广泛宿主范围的重组病毒的包装细胞系,并杜绝了辅助病毒的产生。以重组逆转录病毒载体-包装细胞系这一系统已建立了很多体外以至整体动物内基因转移及表达的模型,有力地促进了基因治疗研究的发展。     

DOC-1R基因重组表达载体构建及其在HeLa细胞中的表达

目的 构建人DOC-1R基因重组逆转录病毒表达载体,实现该基因在体外培养细胞中的大量表达,从而研究表达蛋白的功能。方法 通过重组技术将含有FLAG标签序列的DOC-1R cDNA编码区全长克隆至逆转录病毒载体pLXSN,菌落PCR鉴定、限制性内切酶双酶切及测序验证重组载体的构建。将重组载体转染至GP-293细胞进行病毒包装并以所包装的病毒感染HeLa细胞,通过Western blot及间接免疫荧光染色检测重组DOC-1R蛋白的表达及细胞内定位。结果 测序结果表明重组载体中插入的重组片段序列及开放阅读框架正确,逆转录病毒表达载体pLXSN-FLAG-DOC-1R成功构建。Western blot及间接免疫荧光染色结果证实,逆转录病毒介导的重组DOC-1R蛋白在HeLa细胞中高效表达,表达效率明显高于真核表达载体介导的重组蛋白表达。结论 DOC-1R基因逆转录病毒表达载体成功构建,重组蛋白在体外培养细胞正确高效表达。     

ATPase 抑制因子1是与HCMV pUL23蛋白相作用的宿主蛋白分子-酵母双杂交技术筛选与鉴定

目的： 利用酵母双杂交技术筛选与人巨细胞病毒相互作用的宿主蛋白分子,为探讨人巨细胞病毒pUL23蛋白在HCMV生活周期中的作用机制提供依据。方法: 利用GAL4酵母双杂交系统筛选人胚肾cDNA文库,以获得与人巨细胞病毒pUL23蛋白相互作用的宿主蛋白分子,再通过回交试验和体外GST-pulldown试验验证两者之间的相互作用。结果: 酵母双杂交筛选得到宿主蛋白分子ATPase inhibitory factor 1（ATIF1）,回交试验和体外GST-pulldown试验再次确认ATIF1能够与人巨细胞病毒pUL23蛋白相互作用。结论: pUL23确实能够与ATIF1相互作用,它们之间的相互作用可能为研究pUL23在病毒生活周期发挥的功能提供依据。     

GFP基因转染示踪成肌细胞植入体内的转归

目的实现绿色荧光蛋白(GFP)报告基因在成肌细胞中高效稳定持久的表达,观察成肌细胞作为基因的载体细胞植入SD大鼠体内后的转归。方法构建携带GFP的逆转录病毒载体(pLgXSN),经PT67包装,G418筛选得到稳定的产毒克隆,用含GFP的病毒上清感染成肌细胞。被感染的成肌细胞植入同种动物的后肢的肌肉内,观察其在同种动物体内的转归。于术后4周取动物后肢肌肉,在共聚焦显微镜下观察GFP的表达,HE染色观察组织的结构。结果经双酶切鉴定及测序鉴定证实重组逆转录病毒载体构建成功。转染成肌细胞后48h,在共聚焦显微镜的激光激发下可观察到明亮的绿色荧光,转染效率33%,G418筛选后转染效率达90%。术后4周,在HE染色及共聚焦显微镜下观察可见SD大鼠骨骼肌中转基因的GFP荧光阳性的成肌细胞已与宿主的成肌细胞融合。结论构建的重组逆转录病毒载体,能在成肌细胞中稳定持久的表达,成肌细胞可作为生物细胞工程治疗的载体细胞。     

脆性X精神发育迟缓基因1(FMR1)真核表达载体的构建及其应用

目的构建人脆性X精神发育迟缓基因1(FMR1)真核表达载体,建立稳定转染FMR1的He La细胞系。方法采用PCR扩增出人FMR1的c DNA编码区序列,利用DNA重组技术将其定向插入p EGFP-N2真核表达载体中,并对重组质粒进行双酶切及DNA测序鉴定。用脂质体将验证的重组质粒转染至He La细胞,通过G418筛选建立FMR1稳定转染的He La细胞系。进一步运用Western blot法、免疫荧光染色结合激光扫描共聚焦显微镜技术鉴定FMR蛋白(FMRP)在He La细胞中的表达及定位。结果双酶切和DNA测序结果表明p EGFP-N2-FMR1真核表达质粒构建成功。Western blot和激光共聚焦显微镜结果显示GFP-FMRP融合蛋白在He La细胞中成功表达且主要定位在细胞质。结论成功建立FMR1稳定转染的He La细胞系并可以表达FMRP。     

携带钙整合素结合蛋白基因逆转录病毒表达载体的构建及包装细胞系的建立

目的:构建钙整合素结合蛋白(CIB)的逆转录病毒表达载体,并建立包装细胞系.方法:质粒pet32-CIB经EcoR I和Xho I双酶切后亚克隆至逆转录病毒载体pLXSN,构建重组逆转录病毒表达载体pLXSN-CIB,PCR及双酶切鉴定后,通过脂质体转染导入包装细胞pA317,G418稳定筛选后获得抗性克隆,NIH3T3细胞进行逆转录病毒颗粒谪度测定.结果:重组逆转录病毒表达载体pLXSN-CIB质粒测序结果与GenBank中序列一致,经PCR及酶切鉴定证实,获得了大约574 bp的基因片段,且正确插入pLXSN-CIB载体中；建立了pA317-CIB包装细胞系,采用NIH3T3细胞测定病毒滴度为6.81 ×105 CFU/mL.结论:pLXSN-CIB结构正确,成功构建了CIB基因的逆转录病毒表达载体并建立了pLXSN-CIB包装细胞系.     

人Plk3基因真核表达载体的构建及蛋白表达和定位

目的构建hPlk3真核表达载体并证实融合蛋白在细胞内的表达及定位。方法提取工具细胞Hela的mRNA,反转录为cDNA。PCR扩增hPlk3基因cDNA全长,并将其亚克隆至pEGFP-C1表达载体中。然后将构建的重组质粒进行酶切和测序鉴定,并转染到工具细胞COS-7中,提取细胞蛋白进行Westernblot检测其表达。最后利用激光共聚焦扫描显微镜观察pEGFP-hPlk3在COS-7细胞内的定位。结果hPlk3基因cDNA全长克隆到了真核表达载体pEGFP-C1中,酶切鉴定片段为1941bp,并测序成功。Westernblot检测到了GFP-hPlk3融合蛋白表达,分子量约为98kDa。pEGFP-hPlk3在COS-7细胞中主要定位于细胞质和核周。结论成功构建了hPlk3基因cDNA全长的真核表达载体,pEGFP-hPlk3蛋白在COS-7细胞中主要定位于细胞质和核周。     

hCAP基因真核表达载体的构建及蛋白的表达和定位

目的:构建hCAP真核表达载体并检测融合蛋白在细胞内的表达及定位。方法:提取工具细胞CV-1的mRNA,反转录为cDNA。PCR扩增hCAP基因的cDNA全长,并将其克隆至pEGFP-C1表达载体中。进一步将构建的重组载体进行酶切和测序鉴定,并转染到工具细胞COS-7中,提取细胞蛋白进行Western blot。最后利用激光共聚焦显微镜观察pEGFP-hCAP在NIH3T3成纤维细胞内的定位。结果:hCAP基因cDNA全长克隆到了真核表达载体pEGFP-C1中,酶切鉴定片段为3 879 bp,测序证实成功。Western blot检测GFP-hCAP融合蛋白表达,相对分子质量(Mr)约为169 000。pEG-FP-hCAP在NIH3T3细胞中主要定位于细胞周边。结论:成功构建了真核表达载体pEGFP-hCAP,融合蛋白在NIH3T3细胞中主要定位于细胞周边。     

干扰素诱导蛋白Nmi与人巨细胞病毒皮层蛋白UL23相互作用区域的研究

目的:探究干扰素诱导蛋白N-Myc相互作用因子(Nmi)与人巨细胞病毒(HCMV)皮层蛋白UL23相互作用的关键区域。方法:根据前期实验结果,分别将10个不同截短突变型的Nmi构建到原核表达载体p GEX-4T-1上,转化到大肠杆菌Rosetta(DE3)感受态细胞中,表达并纯化出带有GST标签的融合蛋白,利用GST-pulldown的方法探究Nmi与UL23相互作用的区域。根据GST-Pulldown实验结果,用同源重组的方法在真核表达载体pc DNA4-Myc上分别构建3个缺失突变型Nmi。将实验组和对照组的Nmi分别与含有Flag标签的UL23质粒共转染至He La细胞中,通过免疫共沉淀法进一步研究Nmi与UL23的相互作用区域。结果:(1)10个截短突变型Nmi与GST基因融合的原核表达载体构建成功;(2)3个缺失突变型Nmi与Myc基因融合的真核表达载体构建成功;(3)GST-pulldown实验证明Nmi与UL23相互作用位点位于Nmi上的第192~202位氨基酸区域;(4)免疫共沉淀法确认Nmi的第192~202位氨基酸区域是与UL23相互作用的区域,与GST-pulldown实验结果一致。结论:Nmi与UL23相互作用的区域位于Nmi上第192~202位氨基酸区域。这为阐明UL23帮助HCMV在宿主体内潜伏的分子机理提供了基础。     

Evidence that the human cytomegalovirus 46-kDa UL72 protein is not an active dUTPase but a late protein dispensable for replication in fibroblasts

The Human Cytomegalovirus (HCMV) UL72 gene is considered to be the equivalent of the dUTPase gene of the Alpha- and Gamma-herpesviruses. To characterize its function, the expression profiles of UL72 at both the RNA and the protein level were determined. The gene is expressed with a late kinetics and the corresponding UL72 46-kDa protein accumulates late during infection in the cytoplasm of infected cells. The pUL72 was expressed in E. coli and the purified recombinant protein did not display a detectable dUTPase activity. The viral yields of reconstituted HCMV RVDeltaUL72 viruses carrying a deletion within the UL72 ORF demonstrated a moderate growth defect following low MOI infections, whereas their DNA synthesis profiles were not significantly different from those of the parental HCMV RVAD169. These results demonstrate that the UL72 gene product is not a dUTPase and is not essential for replication in human fibroblasts.     

广州地区人巨细胞病毒临床低传代株UL136基因的序列特征及多态性

目的 研究广州地区新生儿感染人巨细胞病毒(HCMV)临床低传代株UL136基因的序列特征与基因多态性.方法 从10例广州感染新生儿体内分离获得2株(D2、D3)临床HCMV分离株,经多重PCR鉴定后进行UL136基因全序列扩增.PCR产物纯化后进行基因克隆,构建HCMV UL136-pMD18-T重组质粒.经基因测序及应用生物信息学分析方法 ,分析其核酸序列稳定性、编码蛋白质的二级结构与特征.结果 成功分离2株HCMV临床分离株,测序结果 显示,D2、D3及与GenBank中公布的11株临床分离株(4J、51C、39J、33J、63J、22M、10J、32C、29C、27C、Toledo)中,UL136序列高度保守.同源性分析显示在UL136全基因序列1019个核苷酸中,存在30个位点变异,所有的变异均为碱基替换,无插入及缺失突变.编码蛋白的氨基酸序列也高度保守,240个氨基酸残基中,不同临床分离株氨基酸变异率为1.6%～3.7%.不同分离株的UL136蛋白中参与形成二级结构的氨基酸数目及等电点不同.进化树分析结果 显示D2和D3均属于1a群.结论 广州地区临床低传代分离株HCMV UL136基因核苷酸序列及其氨基酸序列极为保守,但仍存在一定多态性.其基因的稳定性提示HCMV UL136开放阅读框(ORF)可能是一个具有重要功能的基因.其编码后修饰位点提示UL136可能与膜受体介导的细胞信号转导通路有关.     

Nuclear body formation and PML body remodeling by the human cytomegalovirus protein UL35

The human cytomegalovirus (HCMV) UL35 gene encodes two proteins, UL35 and UL35a. Expression of UL35 in transfected cells results in the formation of UL35 nuclear bodies that associate with promyelocytic leukemia (PML) protein. PML forms the basis for PML nuclear bodies that are important for suppressing viral lytic gene expression. Given the important relationship between PML and viral infection, we have further investigated the association of UL35 with PML bodies. We demonstrate that UL35 bodies form independently of PML and subsequently recruit PML, Sp100 and Daxx. In contrast, UL35a did not form bodies; however, it could bind UL35 and inhibit the formation of UL35 bodies. The HCMV tegument protein pp71 promoted the formation of UL35 bodies and the cytoplasmic localization of UL35a. Similarly, UL35a shifted pp71 to the cytoplasm. These results indicate that the interplay between UL35, UL35a and pp71 affects their subcellular localization and likely their functions throughout infection.     

Identification and functional analysis of the small membrane-associated protein pUL11 of avian infectious laryngotracheitis virus

pUL11 is a highly conserved, small, acylated, membrane-associated tegument protein of herpesviruses. It is involved in final envelopment of nascent virions in the cytoplasm, although the precise mechanism is still unknown. By screening of mouse monoclonal antibodies (mAb) raised against purified particles of infectious laryngotracheitis virus (ILTV) of chickens (Veits et al., 2003a), we identified two mAb recognizing the 15 kDa UL11 protein (pUL11) of this avian alphaherpesvirus. These mAb permitted detection and precise localization of pUL11 in mature ILT virions, as well as in the cytoplasm of infected chicken cells by Western blot analyses, indirect immunofluorescence tests, and immunoelectron microscopy. For investigation of gene function UL11-deleted ILTV recombinants were generated. Like its homologues in several other alphaherpesviruses, ILTV-pUL11 was shown to be nonessential for productive virus replication. However, compared to wild-type and UL11 rescued ILTV the deletion mutants exhibited significantly reduced virus yields and moderately impaired spread in cell culture. In the absence of pUL11, electron microscopy of infected cells revealed accumulations of tegument proteins with nucleocapsids, and marked distortions of Golgi membranes in the cytoplasm, which obviously inhibited the formation of mature, enveloped virus particles. Taken together, our results demonstrate that pUL11 is relevant for secondary envelopment of ILTV, and confirm functional conservation of this protein in herpesviruses. The now available unique pUL11-specific mAb will help to further analyze this function, which is presumably mediated by physical interactions with other viral gene products, in cultured cells and in the natural animal host of ILTV.     

Recombinant HCMV UL128 expression and functional identification of PBMC-attracting activity in vitro

Human cytomegalovirus (HCMV) has evolved several immune evasion strategies. One strategy is controlling the movement of peripheral blood mononuclear cells (PBMCs) by encoding homologues of chemokines. Our aim was to determine whether HCMV open reading frame (ORF) UL128 could encode a protein that attracts PBMCs like a β-chemokine. The recombinant UL128 protein was synthesized by construction of a stably transfected CHO-UL128 cell line, and a chemotaxis assay showed that UL128 was able to attract PBMCs with a potency equal to that of MIP-1α in vitro. We hypothesize that UL128 protein may act as a β-chemokine homologue in viral pathogenesis.     

The DNA-binding protein P52 of human cytomegalovirus reacts with monoclonal antibody CCH2 and associates with the nuclear membrane at late times after infection.

Monoclonal antibody CCH2 is commonly used for the detection of human cytomegalovirus (HCMV) infected cells in tissue sections as well as in cultured cells. The specificity of CCH2 was determined by screening a recombinant lambda-gt11 cDNA gene bank from HCMV-infected fibroblasts. By sequencing a reactive clone, the antigen was identified to be the non-structural DNA binding protein p52 of HCMV (UL44 reading frame). The viral insert from the lambda clone was recloned in bacterial expression vectors. For this, a new vector, pRos-RS, was constructed. The resulting clones were tested in immunoblot analyses. They were reactive with CCH2 as well as with reconvalescent sera positive for antibodies against HCMV, by this proving the specificity of CCH2. Using this monoclonal antibody in confocal microscopy, the subcellular localization of p52 in infected cells was analyzed. In these analyses, p52 was found to be nuclear and to be associated with the nuclear membrane at late times after infection.     

真核表达质粒pcDNA3.1-tau的构建及在HEK293细胞中的稳定表达

背景：阿尔茨海默病患者的痴呆症状严重程度与脑组织中的神经原纤维缠结数量呈正相关,神经原纤维缠结的主要蛋白成分为过度磷酸化的蛋白tau,tau蛋白的病理改变出现在痴呆症状之前并独立于?-淀粉样多肽的异常。  目的：构建tau基因的真核表达质粒,建立稳定表达tau的稳转细胞株。 方法：采用反转录-聚合酶链反应方法,从反转录反应合成的人成神经瘤细胞(SH-SY5Y)的总cDNA中,扩增出约1.0 kb的tau cDNA片段,用BamHⅠ和XhoⅠ双酶切后定向克隆到真核细胞表达载体pcDNA3.1中,用限制性内切酶酶切分析和DNA序列分析鉴定重组质粒;用脂质体介导法将质粒转染入培养的人胚肾细胞,并利用G418进行稳定表达tau的稳转细胞株的筛选,免疫印迹和免疫荧光细胞化学方法检测tau基因的表达。 结果与结论：人tau cDNA已克隆到真核细胞表达载体pcDNA3.1中;免疫印迹和免疫荧光细胞化学结果显示人tau基因在人胚肾细胞中获得表达,tau蛋白表达的阳性信号主要位于细胞胞质,说明成功构建了pcDNA3.1-tau的真核表达质粒,建立了稳定表达tau的稳转细胞株。