人瘦素的基因克隆及其在COS-7细胞中的表达

目的 构建重组人瘦素哺乳细胞表达载体并在COS-7细胞表达重组人瘦素。方法 提取脂肪细胞总RNA，用RT-PCR扩增人瘦素cDNA并克隆至载体pUCm-T，并对克隆基因进行DNA序列分析。以克隆的人瘦素cDNA为模板，用特异引物扩增瘦素基因，经KpnI和BamH I酶切，插入相应酶切的哺乳细胞表达载体pcDNA3，构建重组哺乳细胞表达载体并转染COS-7细胞，RT-PCR和Western印迹检测其在COS-7细胞中的表达。结果 RT-PCR扩增的DNA片断和预期的人瘦素cDNA大小一致；序列分析显示，克隆的基因序列和文献报道的人瘦素基因序列一致；经RT-PCR和Western印迹鉴定，转染的COS-7细胞可表达、分泌人瘦素。结论 构建了人瘦素的哺乳动物细胞表达载体，并成功地在COS-7细胞中获得重组人瘦素的分泌表达。     

人巨细胞病毒gp52-pp65-pp150的融合表达及应用

目的克隆表达人巨细胞病毒(human cytomegalovirus,HCMV)特异性强的抗原决定簇基因,制备并纯化重组蛋白,并通过组装成捕获法ELISA试剂盒对其抗原性进行评价。方法提取人巨细胞病毒AD169株的DNA,用PCR扩增HCMV的pp150(UL32)、gp52(UL44)、pp65(UL83)基因片段,将3个基因片段串联克隆至原核表达载体pGEX-5x-3进行融合表达和纯化,采用SDS-PAGE电泳法和免疫印迹法(Western blot)对融合基因的克隆及重组蛋白的表达进行鉴定,并组装成捕获法ELISA试剂盒对临床标本进行检测,评价试剂盒的各项性能指标。结果经序列测定各基因片段序列正确,成功构建了HCMV的高效表达融合基因的重组载体gp52-pp65-pp150,表达的融合蛋白经Western blot分析,分子量在50 ku,具有良好的抗原性。将该蛋白组装成捕获法ELISA试剂盒,经232份血清标本的检测,与进口试剂盒相比,本试剂盒的灵敏度为93.91%;特异度为97.43%;粗一致性为96.1%;约登指数为0.901;批内变异系数为12.4%;稳定性良好,37℃保存试剂与4℃保存试剂进行...     

幽门螺杆菌尿素通道蛋白基因UreI的真核载体构建、表达及抗原性研究

目的构建含人幽门螺杆菌(Helicobacter pylori,H.pylori)尿素通道蛋白编码基因(UreI)的真核表达的重组载体,并在COS-7细胞中表达,为核酸疫苗的开发奠定基础。方法以原核表达质粒pET32a(+)/UreI为模板,扩增UreI编码基因片段,将目的基因与同样进行酶切、纯化的载体pEGFP-N1进行连接,而后转化并筛选含有目的基因的重组载体pEG-FP-N1/UreI,并在COS-7细胞中表达,以荧光蛋白和Western blot法检测其表达产物。结果经酶切、测序证实插入的基因片段为H.pyloriUreI蛋白编码基因;荧光显微镜下和Western blot法等检测显示,该重组质粒能够在COS-7细胞中表达目的蛋白,同时能够被H.pylori阳性患者血清所识别。结论成功地构建了真核重组载体pEGFP-N1/UreI,并在COS-7细胞中表达。     

人NKp30基因克隆及其真核表达载体的构建

目的对人NKp30（hNKp30）进行基因克隆并在大肠埃希菌中重组表达,为进一步研究NK细胞抗肿瘤作用奠定基础。方法提取人外周静脉血单个核细胞,分离纯化外周血总RNA。用PCR扩增hNKp30片段,克隆至质粒载体pMD18-T,对克隆的DNA片段行序列分析。用限制酶XhoI、EcoRI消化pMD18-T-hNKp30重组质粒,分离hNKp30片段,插入真核表达载体pIRES2-EGFP相应限制酶位点,酶谱分析鉴定重组表达载体pIRES2-EG-FP-hNKp30,并转染COS-7细胞。结果PCR扩增DNA片段与hNKp30 cDNA大小一致。重组质粒pMD18-T-hNKp30的DNA序列分析显示,克隆DNA序列与文献报道hNKp30的cDNA序列一致。重组表达质粒pIRES2-EGFP-hNKp30转染COS-7细胞后,实现了hNKp30基因在COS-7细胞中的体外转染及瞬时表达。结论采用重组技术成功构建了hNKp30真核表达载体,为探讨NK细胞受体的特性及其信号转导机制奠定了基础。     

以白细胞介素-2为免疫佐剂的幽门螺杆菌粘附素核酸疫苗制备及其免疫预防作用

目的构建含幽门螺杆菌（Hp）粘附素（HpaA）基因和白细胞介素（IL）-2的核酸疫苗，体外转染COS-7细胞，鉴定其表达蛋白的免疫原性和免疫保护作用。方法应用聚合酶链反应（PCR）技术从Hp标准菌株CCUG17874基因组DNA扩增HpaA基因；从重组质粒pCIneo—IL-2扩增小鼠IL-2基因，并通过TA克隆分别克隆人pUCmT载体。检测HpaA及IL-2的核苷酸序列，酶切、连接反应将HpaA和IL-2同时克隆人真核表达载体pIRES，再经PCR法和酶切反应进行鉴定；通过脂质体法将重组载体pIRES-HpaA—IL-2转染COS-7细胞，SDS-PAGE及Western印迹法检测表达蛋白的免疫原性。重组载体转化减毒鼠伤寒沙门菌LB5000，抽提质粒，转化人SL7207，反复传代，鉴定重组核酸疫苗菌的稳定性。以该疫苗菌经口接种小鼠，4周后再用Hp攻击，鉴定感染状况。结果测序结果证实扩增的HpaA基因与HpHpaA序列一致，IL-2序列和小鼠IL-2序列一致。PCR和酶切鉴定结果证实，HpaA和IL-2基因克隆人载体pIRES，成功构建含HpaA和IL-2基因的核酸疫苗质粒pIRES-HpaA—IL-2，Western印迹法检测到相对分子质量分别为30000和14000的HpaA和IL-2蛋白条带。小鼠体内实验显示HpaA—IL-2及HpaA组分别有75．0％、58．4％获免疫保护，与PBS组差异有统计学意义（P〈0．01）。结论成功构建了HpaA和IL-2的Hp减毒沙门核酸疫苗菌，其免疫原性和保护性均得到证实，免疫佐剂IL-2可提高免疫保护率。     

GAD65基因特异siRNA的构建和功能检测

目的构建GAD65基因特异的siRNA并检测体外功能。方法应用RT-PCR方法克隆大鼠GAD65基因、测序、重组病毒包装检测体外功能。针对GAD65基因的编码区,设计3条siRNA片段及一条对照片段,将其分别亚克隆于siRNA的慢病毒表达载体并小量包装获得病毒颗粒(LV-GFP-siRNA-r GAD65);用siRNA病毒颗粒感染GAD65过表达的293细胞,检测GAD65表达情况,从中筛选出高效特异的siRNA。大量包装特异的siRNA病毒颗粒,在体外感染培养的大脑皮质细胞,在体内注射到SD大鼠的苍白球内侧部,检测r GAD65的表达水平,观察siRNA的功能。结果应用RT-PCR方法克隆r GAD65基因,其序列与Gen Bank中的基因序列几乎一致(99.72%),包装病毒后在293细胞中过表达。筛选出针对r GAD65的高效特异的siRNA,在GAD65基因的沉默效率可达到66%。在体外、体内分别应用Western印迹检测感染了LV-GFP-siRNA3-r GAD65的大脑皮质细胞和定点注射了LV-GFP-siRNA3-r GAD65的大鼠GPi。结论成功克隆r GAD65基因,设计、筛选出高效特异的siRNA,并证明这种siRNA在体内和体外均能有效地沉默r GAD65的表达。     

幽门螺杆菌hpaA核酸疫苗的构建及免疫原性检测

目的 构建含幽门螺杆菌(Hp)hpaA基因的核酸疫苗。方法 抽提Hp标准菌株CCUG17874基因组DNA，应用聚合酶链式反应(PCR)技术从基因组DNA扩增hpaA基因，克隆入pUCmT载体，检测hpaA基因序列，经过一系列酶切、连接反应将其克隆入真核表达载体plRES，转入大肠杆菌，筛选阳性克隆，通过PCR和酶切反应鉴定。通过脂质体法将构建好的重组载体pIRES-hpaA转染COS-7细胞，SDS-PAGE及Western印迹法检测pIRES-hpaA表达HpaA蛋白的免疫原性。结果 成功扩增出长约750bp的hpaA基因．测序结果表明扩增出的hpaA基因与Hp hpaA序列一致，PCR和酶切鉴定结果证实hpaA基因克隆入真核表达载体pIRES，成功构建了含hpaA基因的Hp核酸疫苗pIRES-hpaA，并经Western印迹法检测到特异性蛋白条带。结论 构建了hpaA基因的Hp核酸疫苗，为进一步探索其免疫作用奠定了基础。     

人CDK4 cDNA克隆和原核表达

目的 从人肝癌组织细胞中克隆人CDK4基因和原核表达CDK4蛋白.方法 用逆转录PCR方法从人肝癌组织RNA中扩增出CDK4 cDNA,然后与T载体和PET28a＋载体重组,转化受体菌和诱导表达,DNA序列分析和Western blot鉴定重组质粒和蛋白表达.结果 PCR扩增出900 bp的DNA片段,与T载体和PET28a＋载体重组得到人CDK4基因的重组质粒,DNA序列显示为人CDK4的cDNA全序列;IPTG可以诱导重组菌表达蛋白;Western blot结果表明为人CDK4蛋白.结论 用逆转录PCR方法扩增出人CDK4 cDNA,并与PET28a＋载体重组得到能够用IPTG诱导表达的人CDK4蛋白.     

弓形虫核苷三磷酸水解酶-Ⅱ真核表达质粒的构建与鉴定

目的构建弓形虫核苷三磷酸水解酶-Ⅱ(NTPase-Ⅱ)基因真核表达质粒pcDNA3.1(+)-NTPase-Ⅱ并在COS-7细胞中进行瞬时表达。方法以pBAD-HisB-NTPase-Ⅱ质粒为模板,PCR扩增NTPase-Ⅱ目的基因,将其克隆到pcDNA3.1(+)真核表达载体中,双酶切及测序鉴定重组质粒。阳离子脂质体法转染COS-7细胞并经SDS-PAGE和Western Blot检测目的蛋白的表达。结果经鉴定,弓形虫pcDNA3.1(+)-NTPase-Ⅱ核酸疫苗质粒构建成功。以脂质体法转染COS-7细胞后,转染细胞可成功地表达弓形虫NTPase-Ⅱ蛋白。结论证实了弓形虫NTPase-Ⅱ蛋白能在真核细胞中表达,为该基因的核酸疫苗研究提供了实验依据。     

A forest-based approach to identifying gene and gene gene interactions

Multiple genes, gene-by-gene interactions, and gene-by-environment interactions are believed to underlie most complex diseases. However, such interactions are difficult to identify. Although there have been recent successes in identifying genetic variants for complex diseases, it still remains difficult to identify gene-gene and gene-environment interactions. To overcome this difficulty, we propose a forest-based approach and a concept of variable importance. The proposed approach is demonstrated by simulation study for its validity and illustrated by a real data analysis for its use. Analyses of both real data and simulated data based on published genetic models show the effectiveness of our approach. For example, our analysis of a published data set on age-related macular degeneration (AMD) not only confirmed a known genetic variant (P value = 2E-6) for AMD, but also revealed an unreported haplotype surrounding single-nucleotide polymorphism (SNP) rs10272438 on chromosome 7 that was significantly associated with AMD (P value = 0.0024). These significance levels are obtained after the consideration for a large number of SNPs. Thus, the importance of this work is twofold: it proposes a powerful and flexible method to identify high-risk haplotypes and their interactions and reveals a potentially protective variant for AMD.     

HLA基因、CC10基因和结节病

结节病是一种多器官系统受累的肉芽肿性疾病,常侵犯肺部、双肺门淋巴结。其病因目前尚不清楚,本文仅就有关结节病相关基因研究中的两个基因HLA基因、CC10基因和结节病的关系作一简要综述。     

Sex-based differences in gene transmission and gene expression.

The higher prevalence of certain diseases among women suggests involvement of genetic mechanisms linked to the sex chromosomes or of sex-limited gene expression that may be developmentally or hormonally regulated. Analysis of genetic markers and gene expression patterns provides the means for testing hypotheses related to these mechanisms.     

截短序列和全序列HBcAg基因以及HBV C-S融合基因的克隆与表达

目的构建截短序列和全序列HBcAg基因和HBc-HBs Ag融合基因原核表达质粒,研究目的蛋白在大肠杆菌中的表达及其免疫原性。方法利用HBV全基因(adr亚型)质粒pUCm T-HBV分别扩增HBs Ag截短基因、HBcAg截短基因和HBcAg全基因,构建成重组质粒p SK-HBs、p SK-HBc和p KS-HBV C,经DNA序列测定鉴定后,分别将HBcAg截短基因、HBcAg全基因及HBc-HBs Ag融合基因亚克隆至表达质粒PET-30a,在大肠杆菌BL21(DE3)中进行表达HBcAg截短基因、HBcAg全基因和HBc-HBs Ag融合基因产物,采用PAGE-SDS和免疫印迹法对表达产物进行鉴定。结果成功构建了含HBcAg截短基因、HBcAg全基因和HBc-HBs Ag融合基因的原核表达质粒;成功构建的质粒在大肠杆菌BL21(DE3)中能大量表达HBcAg蛋白和HBc-HBs Ag融合蛋白,免疫印迹分析结果显示表达产物具有免疫原性。结论成功构建的原核表达载体在大肠杆菌BL21(DE3)中能顺利表达HBcAg蛋白和HBc-HBs Ag融合蛋白,表达产物具有免疫原性,为慢性乙型肝炎特异性免疫治疗研究提供了实验基础。     

Cancer and gene therapy

 The authors review the current literature pertaining to gene therapy as related to human cancer, covering gene therapy strategies, techniques of gene transfer, and targeted gene delivery. Gene therapy has various applications. Many technical obstacles in gene delivery need to be overcome. The safe delivery and expression of a gene to its destination are essential for clinical use. A greater understanding of the genetic basis of cancer and tumor immunology is necessary before the goal of cancer gene therapy can be fully realized. Received: 5 June 1996 / Accepted: 5 September 1996     

Osteoporosis and gene polymorphism

Osteoporosis is a multifactorial disease for which genetic and environmental factors are determinants. We have been conducting a candidate-gene approach in which polymorphisms of many bone metabolism related genes have been examined in the association study with bone mineral density and fracture incidence. However, the contribution of each gene is small and the major genetic determinants of BMD have not elucidated. Recently, a genome-wide systematic approach has been conducted to find the responsible genes using a genome-wide list of single nucleotide polymorphisms (SNPs). So far, several genes with higher statistical power have been screened out with this approach. The accumulating information of genome science will help understand the pathogenesis of osteoporosis and find the useful ways for the prevention and the treatment of this disease.     

Haemochromatosis and HFE gene

The discovery of the HFE gene has improved classification and diagnosis of iron overload. Most patients with a phenotypic diagnosis of haemochromatosis are homozygote for the C282Y mutation. Among those with other genotypes, only compound heterozygotes, who present the C282Y mutation on one chromosome and the H63D on the other, may present with haemochromatosis, but with a low penetrance and a mild expression. Other patients usually present with another cause of iron overload, such as insulin resistance, alcoholic liver disease or liver cirrhosis. The practical management of haemochromatosis has been greatly modified, since liver biopsy is no more necessary for diagnosis in C282Y homozygotes, and is only needed for exclusion of cirrhosis. Family screening has also greatly benefited from genotyping.