基因工程技术制备中耳炎肺炎球菌疫苗新型蛋白载体

目的应用基因工程技术制备中耳炎肺炎球菌疫苗新型载体——肺炎球菌溶血素（pneumolysin，Pn）。方法根据报道的Pn基因序列，设计一对各带有一个限制性内切酶位点的引物，采用聚合酶链反应（polymerase chain reaction，PCR）技术从肺炎球菌基因组DNA中扩增出Pn基因，对该基因片段进行酶切、回收后克隆入表达载体pET-28a，并转化至大肠杆菌JM109（DE3）宿主细胞中。在培养基中加入异丙基-β-D-硫代半乳糖苷（Isopropy-β-D-thiogalactoside，IPTG）诱导Pn基因的表达，用超声波破菌后，经固化镍树脂亲和吸附和纯化在羧基端带有6个组氨酸的重组Pn蛋白。结果通过常规克隆方法和PCR技术，成功构建Pn基因，DNA测序证实基因构建正确，表达产物相对分子质量约52000，表达量约占总菌体蛋白的8％。结论利用基因工程技术可以克隆Pn基因，并获得该基因在宿主菌中的表达。采用固化镍树脂亲和纯化技术制备出重组Pn蛋白，为进一步研制肺炎球菌多糖和其自身蛋白结合的新型中耳炎疫苗提供参考。     

VEGF-C真核表达载体的构建和体外表达

目的构建血管内皮生长因子C(VEGF-C)基因的真核表达载体,检测其在真核细胞CHO中的表达.方法根据人VEGF-C cDNA的序列,设计合成一对特异性引物,用RT-PCR法克隆乳腺癌细胞MCF-7VEGF-C基因的cDNA,回收PCR产物连接于克隆载体.扩增,质粒提取,酶切鉴定并进行基因序列鉴定.酶切回收VEGF-C cDNA全长的基因片段,与真核表达载体pcDNA3.1(-)连接称重组质粒进行酶切鉴定.采用脂质体转染法将构建的pcDNA3.1(-)/VEGF-C转染至CHO细胞中,G418加压筛选培养.最后用Western-blotting法检测细胞培养上清以及裂解细胞中的VEGF-C蛋白.结果基因测序证实RT-PCR产物包含VEGF-C cDNA全长.重组pcDNA3.1(-)中含有VEGF-C cDNA全长序列,Western-blotting检测到细胞培养上清中以及细胞内有VEGF-C蛋白存在.结论成功构建了人类VEGF-C真核表达载体并检测到载体在真核细胞中的表达.     

人Hath1-cDNA基因的克隆及其真核表达载体的构建

目的克隆人Hath1-cDNA基因,构建其真核表达载体pIRES2-DsRed2-Hath1。方法从人的全血标本中提取DNA模板,经PCR获得Hath1-cDNA,将Hath1-cDNA和pIRES2-DsRed2质粒用限制性内切酶XhoⅠ、EcoRⅠ双酶切,酶切产物琼脂糖凝胶电泳,割胶纯化,前者回收1065 bp大小片断,后者回收大片断,再将回收的2个片断用T4 DNA连接酶连接,转化DH5α,挑选单克隆,提取质粒,所提质粒进行双酶切鉴定并测序。结果成功地从人全血中克隆出Hath1-cDNA,并构建了其真核表达载体pIRES2-DsRed2-Hath1。结论pIRES2-DsRed2-Hath1的构建为Hath1基因转染致聋小鼠耳蜗的实验奠定了基础。     

靶向性超抗原EGF-SEA融合基因的构建及表达

目的：构建金黄色葡萄球菌肠毒素A（SEA）和表皮生长因子（EGF）表达载体。方法：利用PCR及RT-PCR技术分别克隆出SEA基因及EGF基因片断,以经过改良优化的桥式PCR将2个基因融合,再转入表达载体pET-44,经诱导剂诱导后分泌SEA-EGF融合蛋白。结果：所得SEA、EGF基因测序结果示与GENEBANK中公布的标准序列一致,且成功融合SEA-EGF基因并成功导入表达载体。结论：该研究成功构建了SEA-EGF表达载体,为进一步研究SEA-EGF融合蛋白抗头颈肿瘤靶向免疫治疗奠定了基础。     

大鼠核转录因子Atoh1的克隆表达及鉴定

目的利用基因工程方法克隆SD大鼠Atoh1基因CDS区序列,构建大鼠核转录因子Atoh1的真核表达载体并在真核细胞中表达。方法从两只SD大鼠结肠黏膜提取总RNA,采用逆转录PCR法扩增Atoh1基因CDS区序列并亚克隆于PMD-19T载体中。测序鉴定后将Atoh1基因连接于含有EGFP和内部核糖体转入位点(IRES)的真核细胞表达载体pIRES2-EGFP中,对重组质粒进行酶切鉴定和测序鉴定后,以脂质体介导法转染至293T细胞,荧光显微镜和Western blot检测其在293T细胞中的表达。结果扩增得到大鼠Atoh1 CDS区长1 056 bp,编码351个氨基酸,与GeneBank公布的参考序列对比,有两处碱基发生突变,但克隆序列编码的氨基酸序列与参考序列完全一致,两处碱基应为单核苷酸多态性(SNP),突变为无义突变,不影响蛋白表达。双酶切和测序结果证明Atoh1已正确地克隆到真核表达载体pIRES2-EGFP中,荧光显微镜和Western blot证实Atoh1目的蛋白能在293T细胞中稳定表达。结论基因工程方法可成功克隆出Atoh1编码序列,真核表达载体pAtoh1-IRES2-EGFP构建成功并可以在293T细胞中表达。     

CD44基因RNA干扰慢病毒载体的构建与鉴定

目的构建CD44基因RNA干扰（RNA interference,RNAi）慢病毒表达载体并在下咽癌FaDu细胞株上鉴定其沉默效率,为研究目的基因沉默后下咽癌肿瘤细胞致瘤性的改变提供稳定可靠的载体。方法针对目的基因CD44mRNA的序列,按照RNA干扰序列的设计原则,设计、合成4个CD44基因特异性小分子干扰iRNA（small interference RNA,siRNA）靶点,将其合成短发卡hRNA（short hairpin RNA,shRNA）并退火成双链DNA,与慢病毒载体重组形成shRNA表达载体,利用PCR和测序鉴定获取正确克隆。将筛选出的最有效重组载体与慢病毒包装质粒共转染293T细胞并测定病毒滴度。随后将其感染下咽癌FaDu细胞株细胞,采用Real-time PCR检测靶基因的沉默效率。结果对LV-CD44-shRNA载体进行双酶切鉴定,证实短发夹RNA正确插入慢病毒载体,DNA测序证实插入序列正确,CD44基因RNA干扰重组慢病毒载体经293T细胞成功包装后,其病毒滴度为8E＋8TU/ml。RNA干扰下咽癌FaDu细胞CD44基因后,CD44 mRNA水平显著下降,干扰效率大于70%。结论成功构建了CD44基因的shRNA慢病毒表达载体,能够在细胞水平有效沉默靶基因,为CD44基因沉默后下咽癌肿瘤细胞生物学改变的研究打下了较坚实的基础。     

中国人常见GJB2基因突变表达载体的构建及鉴定

目的:构建中国人常见GJB2基因突变235 de1C、299-300 delAT和176 de1 16 bp与增强型绿色荧光蛋白(EGFP)的融合蛋白表达载体,寻找体外研究GJB2基因缺失突变致聋机制的有效途径.方法:用体外定点突变法构建235 de1C、299-300 delAT和176 de1 16 bp突变全序列与EGFP表达载体,以此为模板PCR扩增突变有效表达序列,将PCR产物连接到pMD19-T载体中,EcoRI/BamHI双酶切克隆载体,测序鉴定序列正确性后,将酶切产物插入pEGFP-N1载体中,脂质体转染HEK293细胞,荧光显微镜观察表达的融合蛋白.结果:GJB2基因突变235 de1C、299-300 delAT和176 de1 16 bp在HEK293细胞中高效表达,表达主要位于细胞质中.结论:成功构建了中国人常见GJB2基因突变235 de1C、299-300 delAT和176 de1 16 bp与EGFP的融合蛋白表达载体,为进一步研究其致聋机制奠定了基础.     

人GJB6基因表达载体的构建及鉴定

目的 构建人野生型Cx30与红色荧光蛋白DsRed的融合蛋白表达载体,为揭示Cx30突变患者发病机制提供实验依据.方法 用PCR法扩增GJB6基因,将PCR产物与T载体连接,用双切酶酶切pEASY-GJB6与载体DsRed-N1,连接回收后的片断,构建野生型Cx30编码序列与PDsRed2表达载体,测序鉴定序列正确性.将GJB6-DsRed用脂质体转染HEK293细胞,荧光显微镜观察表达的融合蛋白.结果 GJB6-DsRed在HEK293细胞中高效表达,表达主要位于细胞膜中.结论 成功构建了人野生型Cx30与红色荧光蛋白DsRed的融合蛋白表达载体,为进一步研究非综合征性聋的致聋机制奠定了基础.     

Livin shRNA稳定转染Hep-2细胞系的建立

目的构建靶向Livin基因干扰真核表达质粒,建立干扰质粒稳定转染的Hep-2细胞系,下调Livin基因在Hep-2细胞系中的表达。方法针对Livin基因的mRNA序列设计干扰序列,分别构建1个shRNA质粒表达载体和1个阴性对照质粒,大肠杆菌扩增、酶切及测序鉴定,用脂质体介导转染Hep-2细胞,经G418筛选出稳定转染的细胞系,用Real—timePCR和Westernblot检测Livin在mRNA和蛋白水平的抑制效果。结果经测序证实成功构建pGenesil-LivinshRNA真核表达质粒。干扰质粒稳定转染的Hep-2细胞在荧光显微镜下观察,发出绿色荧光。重组质粒转染Hep．2细胞后,Livin基因在mRNA及蛋白水平明显下降,mRNA水平下调47．17％,蛋白水平下调34．25％。结论成功构建以Livin为靶向的LivinshRNA真核表达质粒。对喉癌Hep-2细胞中Livin的表达具有显著抑制效应,为研究Livin在Hep-2中的功能和喉癌的基因治疗奠定了基础。     

EGFL7基因RNAi重组慢病毒的构建及其对喉癌细胞侵袭的抑制

目的:构建类表皮生长因子域7(EGFL7)基因RNA干扰(RNAi)重组慢病毒,观察其对喉癌体外侵袭的抑制作用。方法:筛选确定的EGFL7基因RNAi有效靶序列,合成靶序列的Oligo DNA,与含H1启动子和绿色荧光蛋白(GFP)的pLV载体连接产生LV-sh EGFL7慢病毒载体,PCR筛选阳性克隆,测序鉴定。用重组慢病毒体外转导喉癌细胞,Western blot法检测喉癌细胞EGFL7蛋白表达。Boyden侵袭小室法实验观察转导shRNA后的喉癌细胞侵袭能力的变化。利用克隆形成实验检测EGFL7基因沉默对Hep-2细胞集落形成能力的影响。结果:成功构建EGFL7的慢病毒载体LV-sh EGFL7,包装慢病毒,浓缩病毒悬液的滴度为5×108 TU/L。转导siRNA的喉癌细胞EGFL7蛋白表达阴性。EGFL7siRNA转导后喉癌胞体外侵袭能力下降。EGFL7基因沉默组细胞克隆集落形成率与Hep-2组细胞及空载体组细胞比较,细胞克隆集落形成率显著减低。结论:成功构建人EGFL7基因RNAi慢病毒载体,EGFL7基因沉默对喉癌细胞体外侵袭有明显的抑制作用。沉默EGFL7后,Hep-2细胞集落形成能力显著减低,...     

Molecular detection and typing of human papillomavirus in laryngeal carcinoma specimens

CONCLUSIONS: Human papillomavirus (HPV) DNA was detected in 32% of laryngeal carcinoma biopsy samples studied. The genotypes identified were high-risk types, the most frequent being HPV 16. Viral DNA was integrated into the host genome (genotype HPV 16), providing supporting evidence for a role of HPV in the carcinogenic pathway of laryngeal squamous cell carcinoma. OBJECTIVE: HPV has been detected in laryngeal lesions, both benign and neoplastic, with a variable frequency (8-60%). These viral agents have been proposed as an adjuvant or cofactor in head and neck carcinogenesis because of their oncogenic properties. The aims of this study were to identify HPV in laryngeal carcinoma samples and to describe the physical state of the viral genome, i.e. its integration to the host DNA. MATERIAL AND METHODS: Formalin-fixed, paraffin wax-embedded tumor samples from patients with newly diagnosed laryngeal carcinomas were collected. The HPV genome was identified using polymerase chain reaction (PCR) with primers complementary to the conserved region L1 (MY09-11). Genotyping was accomplished by restriction fragment length polymorphism. Samples positive for HPV 16 were assayed by PCR with primers complementary to region E2, interrupted during viral genome integration. RESULTS: Ten of the 31 samples (32%) were positive for HPV DNA and all of the samples were positive for human beta-globin. The genotypes identified were HPV 16 (n=3), HPV 58 (n=2) and HPV 39, 45, 51, 59, 66 and 69 (n=1 for each). The three samples positive for HPV 16 had lost region E2, meaning that the viral DNA had been integrated into the host genome.     

人B7-1 cDNA的克隆及鉴定

［摘要］目的：克隆人B7 1全长cDNA以构建相应腺病毒表达载体。方法:根据B7 1基因序列设计并合成可扩增B7 1 cDNA的特异性引物，用RT PCR法从骨髓细胞总RNA中扩增B7 1 cDNA，并克隆至pGEM T载体中，经酶切鉴定后再行序列分析。结果: 逆转录多聚酶链反应扩增产物长度与预期的889 bp一致; 用M13正、反向引物行序列测定，证实克隆出的序列与GenBank的B7 1 cDNA序列完全一致; 人B7 1全长cDNA被成功地插入到质粒pGEM T中。结论: 克隆人B7 1全长cDNA为构建相应腺病毒表达载体及应用B7 1行肿瘤免疫基因治疗提供了可能性。     

GJB2全序列长链PCR和琼脂糖凝胶电泳方法研究

目的：探讨GJB2全序列长链PCR方法和琼脂糖凝胶电泳方法，以及影响长链PCR和电泳结果的可能因素。方法应用Primer Premier 5.0软件和Oligo 6 Demo软件针对GJB2全序列设计引物，应用DNA聚合酶KOD FX Neo试剂盒进行两步法长链PCR扩增，调整加入DNA模板量、PCR延伸时间、循环次数等影响PCR产物量，通过0.8%琼脂糖凝胶电泳检测PCR产物长度和量，调整加样槽的宽度、加样量、电泳电压、电流、电泳时间得到清晰条带，若PCR产物存在大片段碱基插入或缺失，用限制性内切酶BamHI进行内切酶反应，初步判断插入或缺失的大致位置。结果正向引物F：5’-AGATCGGGACCTCGAAGGGGACTTG-3’；反向引物R：5’-AGGTGGGCACGGGGTTAGGTAGAAA-3’，扩增片段长5887 bp。长链PCR条件为：50μl的反应体系中加入2μl（约40 ng）的基因组DNA，预变性94℃2分钟，变性98℃10秒，68℃延伸5分钟，共32个循环。电泳条件为：加样槽5 mm宽，每槽加样0.8μl PCR产物，电泳电压50 V，电流50 mA，电泳时间140分钟。结论应用DNA聚合酶KOD FX Neo试剂盒进行两步法长链PCR，可进行GJB2全序列扩增，影响PCR的可能因素为引物、DNA模板的质和量、延伸时间、循环次数等。0.8%琼脂糖凝胶电泳可获得较好的分离效果，影响电泳可能的因素为加样槽宽度、加样量、电泳电压、电流、电泳时间等。     

Molecular detection and typing of human papillomavirus in laryngeal carcinoma specimens

Conclusions. Human papillomavirus (HPV) DNA was detected in 32% of laryngeal carcinoma biopsy samples studied. The genotypes identified were high-risk types, the most frequent being HPV 16. Viral DNA was integrated into the host genome (genotype HPV 16), providing supporting evidence for a role of HPV in the carcinogenic pathway of laryngeal squamous cell carcinoma. Objective. HPV has been detected in laryngeal lesions, both benign and neoplastic, with a variable frequency (8–60%). These viral agents have been proposed as an adjuvant or cofactor in head and neck carcinogenesis because of their oncogenic properties. The aims of this study were to identify HPV in laryngeal carcinoma samples and to describe the physical state of the viral genome, i.e. its integration to the host DNA. Material and methods. Formalin-fixed, paraffin wax-embedded tumor samples from patients with newly diagnosed laryngeal carcinomas were collected. The HPV genome was identified using polymerase chain reaction (PCR) with primers complementary to the conserved region L1 (MY09-11). Genotyping was accomplished by restriction fragment length polymorphism. Samples positive for HPV 16 were assayed by PCR with primers complementary to region E2, interrupted during viral genome integration. Results. Ten of the 31 samples (32%) were positive for HPV DNA and all of the samples were positive for human β-globin. The genotypes identified were HPV 16 (n=3), HPV 58 (n=2) and HPV 39, 45, 51, 59, 66 and 69 (n=1 for each). The three samples positive for HPV 16 had lost region E2, meaning that the viral DNA had been integrated into the host genome.     

construction of prokaryotic expression vector for pbv220/nt4-adnf-9

Objective To construct a prokaryotic expression vector bearing fusion gene NT4-ADNF-9 for future studies on genetic therapies for sensorineural deafness. Methods Double strand ADNF-9 Edna was synthesized using asymmetrical primer/templates and ligated to the 3' terminal of signal and leader peptides of neurotrophin 4 (NT4). The fusion gene NT4-ADNF-9, was subeloned into prokaryotic expression vector Pbv220, and named Pbv220/NT4-ADNF-9. DNA sequence of the fusion gene was analyzed. The fusion protein was isolated by SDS-PAGE and its bioactivity was evaluated using primary culture of day 8 chicken embryonic DRGcells. Results The correct sequence of fusion gene NT4-ADNF-9 was successfully subcloned into the Pbv220 vector. The expressed ADNF-9 protein showed its effects in promoting cell survival and neurite growth. Conclusion Prokaryotic expression vector Pbv220/NT4-ADNF-9 was constructed successfully and the expressed fusion protein demonstrated satisfactory bioactivity.