重组Prohibitin融合蛋白包涵体的纯化

[目的]获得高纯度具有免疫活性的Prohibitin融合蛋白.[方法]异丙基-β-D硫代半乳糖苷(IPTG)诱导重组大肠杆菌BL21(pET30a( )-prohibitin)表达,其融合蛋白包涵体经过洗涤、变性、复性后,用Ni-NTA Agarose亲和层析柱分离纯化.通过12%SDS-PAGE胶和Bradford法检测其纯度和目的蛋白含量,用ELISA对纯化后的蛋白进行鉴定.[结果]从融合蛋白包涵体中纯化到具有免疫活性的目的蛋白,其纯度达90%以上,含量约0.3mg/ml.[结论]建立了有效纯化融合蛋白包涵体的方法,为对Prohibitin进一步的结构和功能研究奠定基础.     

宫颈癌患者HPV16型E6蛋白的表达纯化及血清抗体检测

背景与目的:人乳头瘤病毒16型(humanpapillomavirustype16,HPV16)是宫颈癌组织中最常见的高危HPV,其相应蛋白的血清抗体与宫颈癌的发生发展相关。本研究构建HPV16E6重组表达载体并表达纯化获得HPV16E6重组蛋白,用于检测不同人群血清相应抗体,初步探讨本地区HPV16E6血清抗体反应与宫颈癌的相关性。方法:将HPV16E6基因与pRSET-A融合表达载体连接,获得E6表达重组体,转化大肠杆菌BL21(DE3)并用异丙基硫代-$-D-半乳糖苷(isopropylthio-$-D-galactoside,IPTG)诱导表达。表达的包涵体变性后经Ni柱纯化,复性并经活性鉴定后,用以包被ELISA板,检测正常女性、慢性宫颈炎患者和宫颈癌患者血清抗体。同时采用荧光偏振方法分型检测宫颈癌组织HPVDNA。结果:pRSET-16E6表达重组体的工程菌经IPTG诱导后可表达Mr24×103的HPV16E6组氨酸融合蛋白,表达量占菌体蛋白的22.3%。表达形式为包涵体,重组蛋白纯度达95%以上,其活性经ELISA法证实。80例正常女性、46例慢性宫颈炎和32例宫颈癌患者血清抗体阳性率分别为5.0%、6.5%和31.2%,宫颈癌患者HPV16E6血清抗体阳性率显著高于正常人(P<0.002)及慢性宫颈炎患者(P<0.01),而正常人与慢性宫颈炎患者间的差异无显著性。32例宫颈癌患者癌组织中,HPVDNA阳性率90.6%,HPV16DNA阳性率46.9%。HPV16DNA阳性组血清HPV16E6抗体阳性率(46.7%)高于阴性组(17.6%),但两组间的差异无显著性(P>0.05)。结论:在pRSET-A/BL21中表达获得的HPV16E6融合蛋白,可用于宫颈癌相关HPV的血清学研究;宫颈癌患者HPV16E6血清抗体阳性率明显高于正常人和慢性宫颈炎患者。     

HPV16E7-HSP70嵌合型DNA疫苗通过Fas-FasL途径的抗肿瘤作用

目的 运用表达人乳头瘤病毒16型(HPV16)E7蛋白的肿瘤细胞系B16 HPV16E7,探讨pcdHPV16mE7-HSP70融合DNA疫苗抗肿瘤的可能机制.方法 运用流式细胞术检测IFN-γ对B16HPV16E7细胞表面Fas分子表达的影响.通过ELISA和流式细胞术检测疫苗免疫后小鼠脾淋巴细胞IFN-γ的分泌和FasL的表达情况.运用体外抗体阻断实验检测Fas-FasL途径对pcd-HPV16mE7-HSP70DNA疫苗抗肿瘤作用的影响.结果 pcd-HPV16mE7-HSP70 DNA疫苗可以激活机体的免疫系统,上调细胞因子IFN-γ和E7特异性FasL的表达.IFN-γ可以激活B16-HPV16E7肿瘤细胞表面的Fas分子的表达.拮抗FasL后,疫苗对B16-HPV16E7肿瘤细胞的杀伤作用明显减弱.结论 Fas-FasL途径是pcd-HPV16mE7-HSP70 DNA疫苗抗肿瘤作用的重要机制之一.     

重组人GST/MCP-1融合蛋白纯化及其抗肿瘤作用的研究

从高表达GST/MCP-1的菌株纯化GST/MCP-1,其表达产物以包涵体形式存在.包涵体经分离洗涤后,探索了对其变性复性的最佳条件.复性后的样品经Glutathione Sepharose 4B一步亲合层析纯化,获得了具有生物学活性的SDS-PAGE纯的GST/MCP-1.Western Blot检测表明,纯化的GST/MCP-1可与MCP-1抗体发生特异反应.体外抗肿瘤试验表明,CST/MCP-1激活单核细胞及淋巴细胞后,具有抑制肿瘤细胞生长的能力.裸鼠抗肿瘤试验同样显示明显的抑制反应.上述结果提示MCP-1具有抗肿瘤能力.     

小鼠成纤维细胞激活蛋白α二肽基肽酶核心序列原核表达与纯化及复性

表达质粒,通过对转化该质粒后的感受态细菌进行菌液PCR鉴定以及对该质粒进行BamH I和Xho I双酶切鉴定,鉴定结果与预期结果完全一致;实现了对该质粒编码的融合蛋白His6-FAPαc的表达,表达后的融合蛋白主要以包涵体的形式存在,表达产量占菌体总蛋白＞70%;纯化了该融合蛋白,纯化后的蛋白纯度通过灰度分析＞99%;对该融合蛋白进行了复性,复性后该融合蛋白由不溶的包涵体状态变为可溶的水溶状态.结论:成功表达、纯化和复性了FAPα二肽酶催化核心区域FAPαc,为深入开展FAPα的研究奠定基础.     

抗人肺腺癌单链抗体的构建及在大肠杆菌中的表达

目的:构建抗肺腺癌的单链抗体(scFv),研究其表达条件,为将这一小分子抗体应用于临床奠定基础.方法:将抗人肺腺癌单克隆抗体的重链及轻链可变区基因插入表达载体pFUW80、pTH、pTF,分别在大肠杆菌XL1-Blue、Top10、GI698/GI724中诱导表达,得到噬菌体抗体或包涵体.用SDS-PAGE和ELISA鉴定检测活性.结果:SDS-PAGE的结果表明,在pTH和pTF的表达产物中,有一条43kD的特异条带,其分子量与预期相符,单链抗体以包涵体形式出现,其表达量达细菌总蛋白的18.6%.ELISA的结果表明,噬菌体抗体和经复性处理的包涵体具有与亲本单抗相同的特异性.结论:成功地构建和在大肠杆菌中表达了抗肺腺癌单链抗体.     

癌-睾丸抗原GAGE-1基因的重组、表达及纯化

目的 为进一步研究临床应用癌-睾丸抗原GAGE-1诱导特异性抗肿瘤免疫反应,对GAGE-1基因进行克隆、体外原核重组表达及蛋白分离纯化。方法 运用RT-PCR技术从人QGY-7701肝癌细胞株中扩增GAGE-1基因片段,插入原核表达载体pGEX-6p-1中,构建重组表达质粒pGEX-6p-1-GAGE-1,并导入大肠杆菌BL21,IPTG诱导目的蛋白表达;经包涵体透析复性及GST柱亲和层析纯化目的蛋白,SDS-PAGE电泳分析鉴定。结果 扩增得到GAGE-1基因5’端251 bp片段,与GeneBank公布的序列一致,构建的PGEX-6p-1-GAGE-1原核表达质粒经IPTG诱导,在大肠杆菌中表达分子量约35.7 kD的GST-GAGE-1融合蛋白,纯化后蛋白纯度为90%以上。结论 成功构建PGEX-6p-1-GAGE-1重组表达质粒,并成功表达纯化了GST-GAGE-1融合蛋白,为进一步深入研究GAGE蛋白奠定了基础。     

LRP16融合蛋白载体的构建及其原核表达

目的观察和鉴定LRP16在大肠杆菌中的表达,并分离、纯化其蛋白产物。方法应用DNA重组技术,用RT-PCR方法从正常人血液中扩增出LRP16基因全长及其抗原表位区,构建重组表达质粒pRSET-C-LRP16,IPTG诱导表达并纯化融合蛋白采用SDS-PAGE凝胶电泳进行鉴定。结果成功构建LRP16基因融合蛋白载体,SDS-PAGE显示pRSET-C-LRP16表达于原核细胞,蛋白经电泳分离,切胶后获得纯化的LRP16蛋白。结论制备的高纯度的LRP16蛋白,可在大肠杆菌中稳定表达。     

肿瘤-睾丸抗原LAGE-1基因的原核表达纯化和抗血清制备

目的:构建人肿瘤-睾丸抗原LAGE-1的原核表达质粒,表达、纯化LAGE-1融合蛋白并制备GST-LAGE-1多克隆抗体。方法:逆转录聚合酶链反应(RT-PCR)方法扩增人肝癌组织LAGE-1基因3′端片段,连入原核表达载体pGEX-4T-1( ),构建原核表达质粒pGEX-LAGE-1并测序。将该质粒转化大肠埃希菌BL21(DE3)进行诱导表达,经包涵体透析复性和谷胱甘肽巯基转移酶纯化系统分离纯化目的蛋白。用纯化的融合蛋白GST-LAGE-1免疫新西兰大白兔,间接ELISA法测定抗体效价,饱和硫酸铵沉淀法纯化抗体,并采用Western blot检测GST-LAGE-1多克隆抗体特异性。结果:RT-PCR扩增得到LAGE-1基因3′端264bp片段,测序结果与GenBank公布序列一致;成功构建pGEX-LAGE-1原核表达质粒,含有该质粒的大肠埃希菌经IPTG诱导后表达相对分子质量约为36×103的蛋白,经包涵体复性和GST融合蛋白纯化系统纯化,得到重组蛋白GST-LAGE-1,纯度达90%;制备兔抗GST-LAGE-1抗体,纯化的抗体经Western blot证实可与目的蛋白特异性结合。结论:获得了纯化的肿瘤-睾丸抗原LAGE-1重组蛋白及其特异性多克隆抗体,为进一步研究LAGE-1抗原在肿瘤免疫治疗中的作用奠定基础。     

小细胞肺癌2F7单抗ScFv的高效表达及复性研究

目的 在大肠杆菌中高效表达小细胞肺癌单抗2F7的单链抗体（ScFv)，并获得具有生物学活性的ScFv。方法 利用PCR方法将2F7单抗重链可变区（VH）和轻链可变区（VL）通过一人工设计的柔性连接肽（Linker)连接，再将单链抗体基因重组到原核表达载体pQE31中，构建单链抗体高效表达载体pQE-2F7-ScFv。将pQE-2F7-ScFv质粒转化大肠杆菌M15后诱导表达，并对表达产物进行纯化和稀释复性。结果 获得了2F7单链抗体的高效表达，表达蛋白大小约27.4kD，以包涵体形式存在。包涵体蛋白在经过变性、纯化和稀释复性后，获得了有功能的单链抗体。结论 成功地构建和表达了小细胞肺癌单抗F27的单链抗体，并对其进行了纯化和复性，将进一步促进2F7单抗小分子抗体的应用。     

Vaccination of full-length HPV16 E6 or E7 protein inhibits the growth of HPV16 associated tumors

Cervical cancer is the second most common cancer in women worldwide. Human papillomavirus (HPV) is the primary etiologic agent of cervical cancer. Two HPV16 proteins, E6 and E7, are consistently expressed in tumor cells. Most therapeutic vaccines target one or both of these proteins. Taking the advantages of safety and no human leukocyte antigen restriction, protein vaccine has become the most popular form of HPV therapeutic vaccines. Here we demonstrate that immunization with full-length HPV16 E6 or E7 protein elicited specific immunological effect and inhibition of TC-1 cell growth using TC-1 mouse model. HPV16 E6 and E7 genes were cloned into pET-28a(+) and introduced into E. coli Rosetta. Expression of the genes was induced by IPTG. Proteins were purified by Ni-NTA agarose and they were detected by SDS-PAGE and Western blotting. C57BL/6 mice were vaccinated with 1.5 nmol HPV16 E6 or E7 protein. Then they were implanted with 1x10(5) TC-1 cells. No tumor was detected in any mouse vaccinated with E7 protein. Forty days later, the tumor-free mice and control mice were challenged with 2x10(5) TC-1 cells. All control mice developed tumors 6 days later, but E7 immunized mice were tumor free until 90 days. Tumor growth was slow in the E6 immunized mice, but 83% of the mice developed tumors and the survival percentage was not significantly different from the control. An adoptive immune model was used to demonstrate the therapeutic effect. Results showed that the development of TC-1 cells was obviously reduced by transfusion of T-cells but not serum from mice immunized with E7 protein. T-cells from E7 immunized mice also induced the lysis of TC-1 cells in the cytotoxic T lymphocyte assay. These findings show that immunization with HPV16 E6 or E7 protein was able to elicit specific protective immunity against TC-1 tumor growth.     

宫颈癌组织HPV58的检测及其E7基因的克隆和表达

目的　检测宫颈癌组织中人乳头瘤病毒 5 8型 (HPV5 8)并克隆表达其E7基因。方法采用GP5 /GP6 引物系统扩增 5 8例宫颈癌组织 ,将荧光偏振 (FP)检测技术与模板指导的末端延伸反应 (TDI FP)结合 ,检测HPV5 8,确定HPV5 8感染阳性宫颈癌组织。用特异引物从HPV5 8阳性标本中扩增HPV5 8早期表达蛋白E7基因 ,将其连入pGEM TEasy载体 ,获得克隆重组体HPV5 8E7 pGEM T ,并测序验证。将E7基因与pRSET A融合表达载体连接 ,获得E7表达重组体pRSET 5 8E7,转化大肠杆菌BL2 1(DE3) ,并用IPTG诱导表达。结果　 5 8例宫颈癌标本中 ,HPV5 8阳性 10例 ,占 5 2例HPV阳性标本的 19.2 %。从其中扩增到了HPV5 8E7基因并构建了其克隆和表达重组体。其表达重组体经IPTG诱导后 ,可表达Mr16× 10 3 的HPV5 8E7His6融合蛋白 ,表达量占菌体蛋白的 30 %。结论　欧美国家少见的高危HPV5 8在中国陕西人宫颈癌组织中并不少见。HPV5 8E7重组表达体可在大肠杆菌中高效表达 ,为HPV5 8相关肿瘤诊断试剂及疫苗的研制奠定了初步基础     

HPV16E7基因沉默对宫颈癌细胞系CaSki细胞增殖的影响

[目的]探讨脂质体转染HPVl6E7siRNA对人宫颈癌CaSki细胞增殖的影响。[方法]人工合成抑制HPVl6E7基因的siRNA片段,通过脂质体转染到CaSki细胞内,显微镜下观察其形态学变化;流式细胞术检测各组细胞周期变化;RT-PCR检测HPVl6E7mRNA的表达;Westernblot检测HPVl6E7蛋白表达。[结果]转染siRNA后的CaSki细胞,细胞增殖受到显著抑制．HPVl6E7mRNA表达显著下降,HPVl6E7蛋白水平显著下降。[结论]应用RNA干扰靶向抑制HPVl6E7基因可以显著抑制CaSki细胞增殖。     

肝癌相关抗原H2-calponin基因重组质粒的构建与表达

目的应用基因工程的方法构建H2-calponin(CNN2)基因工程表达质粒,体外表达、分离、纯化CNN2蛋白。方法以PCR扩增CNN2cDNA序列,用基因工程技术将CNN2基因重组到表达质粒pColdⅢ中,转化BL21(DE3)pLysS宿主菌,以SDS-聚丙烯酰胺凝胶电泳(sodium dodecyl sulfate polyacrylamideg elelectrophoresis,SDS-PAGE)检测目的蛋白的表达情况,优化表达条件,以较大体积培养基因工程菌,菌体经超声波破菌后,过Ni-NTA亲和柱纯化,Western-blot检测表达纯化的融合蛋白。结果转化有pColdⅢ-CNN2重组质粒的基因工程菌能诱导表达CNN2蛋白,表达的目的蛋白占总菌体蛋白的35%;SDS-PAGE检测发现菌体上清液和沉淀物中均有目的蛋白片段,证实部分CNN2蛋白以可溶性形式表达;Western-blot检测结果提示表达纯化的蛋白能与抗CNN2抗体发生反应。结论成功构建出表达可溶性CNN2蛋白的重组质粒,诱导表达的蛋白具有CNN2免疫原性。     

Antibodies against the human papillomavirus type 16 early proteins in human sera: correlation of anti-E7 reactivity with cervical cancer

By Western blot technique, 519 samples of human sera were tested for the presence of antibodies to the human papillomavirus (HPV) type 16 proteins E4 and E7 that had been expressed in Escherichia coli as fusion proteins. Sera were obtained from patients attending the University hospitals for reasons unrelated to HPV infections (controls), from patients with HPV-associated lesions, as well as from patients suffering from cervical cancer. Within the control population, 18.1% of them had antibodies that reacted with the E4 protein, and 3.9% of them had antibodies that reacted with the E7 protein. No sex-specific difference in the antibody prevalence was observed. The highest proportion of anti-E4 antibody-positive individuals (40.7%) was observed in the age group between 11 and 20 years. The frequency of anti-E4-positive sera was threefold higher in patients with HPV-associated genital lesions than that in age-matched controls. Antibodies against the HPV16 E7 protein were found 14 times more frequently in patients with cervical cancer, compared with age- and sex-matched controls (P less than .00001). From these data, we concluded that anti-E4 antibodies may be correlated with virus replication and that anti-E7 antibodies may represent a marker for cervical cancer development.     

乳腺浸润性导管癌组织中HPV16DNA与p53蛋白表达的研究

 目的 检测人乳腺浸润性导管癌组织中HPV16DNA和p53蛋白，探讨HPV16型感染和p53蛋白表达与人乳腺癌之间的关系。方法 采用分子原位杂交和免疫组化技术检测和分析50例乳腺浸润性导管癌、30例正常乳腺组织中HPV16DNA和p53蛋白二者之间的表达关系。结果 癌组中HPV16DNA阳性和HPV16DNA阴性两组阃p53蛋白的表达均有显著性差异（P〈0．01），HPV16DNA阳性组显示与p53蛋白表达呈负相关（P〈0．02）。结论 HPV16感染后导致野生型p53的降解可能涉及HPV16感染后人乳腺上皮细胞癌变的病理发生过程。     

Oral administration of human papillomavirus type 16 E7 displayed on Lactobacillus casei induces E7-specific antitumor effects in C57/BL6 mice

The mounting of a specific immune response against the human papillomavirus type 16 E7 protein (HPV16 E7) is important for eradication of HPV16 E7-expressing cancer cells from the cervical mucosa. To induce a mucosal immune response by oral delivery of the E7 antigen, we expressed the HPV16 E7 antigen on the surface of Lactobacillus casei by employing a novel display system in which the poly-gamma-glutamic acid (gamma-PGA) synthetase complex A (PgsA) from Bacillus subtilis (chungkookjang) was used as an anchoring motif. After surface expression of the HPV16 E7 protein was confirmed by Western blot, flow cytometry and immunofluorescence microscopy, mice were orally inoculated with L. casei-PgsA-E7. E7-specific serum IgG and mucosal IgA productions were enhanced after oral administration and significantly enhanced after boosting. Systemic and local cellular immunities were significantly increased after boosting, as shown by increased counts of lymphocytes (SI = 9.7 +/- 1.8) and IFN-gamma secreting cells [510 +/- 86 spot-forming cells/10(6)cells] among splenocytes and increased IFN-gamma in supernatants of vaginal lymphocytes. Furthermore, in an E7-based mouse tumor model, animals receiving orally administered L. casei-PgsA-E7 showed reduced tumor size and increased survival rate versus mice receiving control (L. casei-PgsA) immunization. These results collectively indicate that the oral administration of E7 displayed on lactobacillus induces cellular immunity and antitumor effects in mice.     

人生存素基因的克隆、表达与抗血清制备

目的克隆表达重组人生存素,制备其抗血清并检测其免疫识别活性。方法用RT-PCR方法从培养的人白血病细胞株HL-60中克隆人生存素cDNA,克隆到原核表达载体pET32a(+),重组质粒转化大肠杆菌BL21(DE3)进行表达,目的蛋白经Ni-NTA树脂亲和纯化后免疫小鼠制备抗血清,ELISA检测抗血清的效价,Western blot和免疫细胞化学法鉴定抗血清的特异性。结果所克隆生存素cDNA序列与Genbank中序列完全一致,将其读码框插入原核表达载体pET32a(+)诱导表达后,SDS-PAGE电泳分析证实重组蛋白为分子量约37KD的融合蛋白,表达量占总菌体的30%,纯化后融合蛋白的纯度为95%,所制备的鼠抗血清的效价达1:1600,Western blotting证实其有较好的特异性,可以检测肿瘤细胞生存素的表达。结论我们已克隆并表达了人生存素基因,所制备的抗人生存素血清可用于相关肿瘤检测。