鼠精子表面蛋白cyritestin在沙门氏菌平衡致死系统中的高效表达

目的 松建表达鼠精子cyritestin蛋白的可口服减毒沙门氏菌活疫苗株。方法 将编码成熟cyritestin蛋白cDNA序列的酶切片段插入含pUC复制子的表达载体pYA3339中,构建重组质粒pMCY,将该重组质粒转入鼠沙门氏伤寒杆菌疫苗株X4550,获得杂合菌株X4550（pMCY）。应用 western blot对重组菌所表达的重组cyritestin蛋白进行免疫分析,结果 该无抗药性的杂合菌株在体外营养选择压力下可较稳定携带重组质粒传代繁殖,在体内可较稳定地定居于Peyer‘s结、肠系膜淋巴结和脾脏。该重组菌可高水平表达重组cyritestin蛋白。结论 高效表达cyritestin蛋白的X4550（pMCY）疫苗株可用于免疫性避孕研究。     

表达pCDR1 Th表位减毒鼠伤寒沙门菌株的构建

目的构建表达pCDR1 Th表位的可口服减毒鼠伤寒沙门菌株。方法全基因合成pCDR1两条核苷酸链，在C端加上6-His标签，退火互补后插入原核表达载体pYA3149中，构建重组质粒pR1，将该重组质粒转入鼠沙门菌终宿主菌株X4550，获得杂合菌株X4550（pR1）。体外诱导表达后斑点印迹鉴定表位肽的表达。结果酶切鉴定和基因序列测定显示重组质粒构建成功。体外诱导后6h细菌裂解上清液中，检测到表位肽的表达，该蛋白能与鼠抗His单克隆抗体特异结合。重组菌株在体外营养选择压力下，可较稳定地携带重组质粒传代繁殖。结论成功构建了能稳定表达pCDR1 Th表位的可口服减毒鼠伤寒沙门菌株。     

弓形虫GRA7基因的克隆表达及免疫分析

本文构建了刚地弓形虫RH株致密颗粒蛋白7(GRA7)基因原核表达重组质粒,进行蛋白表达并分析重组蛋白的免疫反应性.设计合成引物,从弓形虫RH株基因组DNA中特异扩增出GRA7基因片段并进行序列分析.目的片段用EcoR Ⅰ和BamH Ⅰ双酶切后分别构建重组质粒pET32a-GRA7和pET28a-GRA7,而后转入大肠埃希菌BL21 (DE3)中诱导表达,Western blotting分析表达蛋白.结果显示,从弓形虫RH株中成功扩增出大小约710 bp的GRA7基因片段,构建的重组质粒经双酶切和PCR鉴定及测序,目的基因片段与预期相符.重组质粒pET32a-GRA7经IPTG诱导后,可高效表达重组蛋白,Western blotting分析显示重组GRA7蛋白能被弓形虫慢性感染血清识别,而重组质粒pET28a-GRA7未能诱导表达出目的蛋白.原核表达的重组GRA7抗原具有特异的免疫反应性,为弓形虫的诊断应用和疫苗研究奠定了基础.     

表达胃癌MG7-Ag模拟表位的减毒鼠伤寒杆菌疫苗的研制和初步鉴定

目的 研制可表达胃癌MG7－Ag模拟表位的减毒鼠伤寒杆菌疫苗。方法 将NcoI位点和MG7－Ag模拟表位编码序列的互补序列设计到上游引物的5′端。以含有HBcAg全序列的质粒p1.2Ⅱ为模板，通过PCR扩增，获得MG7－Ag模拟表位与HBcAg的融合基因。将目的基因插入载体pUCm-T，经酶切鉴定和序列测定证实后，再亚克隆至与减毒鼠伤寒杆菌X4550互补的质粒pYA3341中，再以此重组质粒转化减毒鼠伤寒杆菌X4550。结果 序列测定证实，PCR产物为胃癌MG7－Ag模拟表位与HBcAg的融合基因片段；最终得到含有目的基因片段的重组表达载体pYA3341。重组质粒在X4550中的表达产物，经Western blot表明，在相对分子质量（Mr)约在22000处有1条可与抗MG7 mAb特异性结合的多肽表位。结论 成功地研制可表达胃癌MG7－Ag模拟表位减毒鼠伤寒杆菌疫苗，为进一步研究其在胃癌免疫治疗中的作用奠定了基础。     

幽门螺杆菌UreB-Omp11融合蛋白的重组疫苗候选株构建和融合蛋白的表达、纯化及免疫学活性

目的：构建幽门螺杆菌（Hp）UreB-Ompll融合蛋白的重组疫苗候选株，在大肠杆菌中表达UreB-Ompll融合蛋白，并检测其免疫学活性。方法：用PCR方法扩增郑州分离坳菌株MEL-HP27的ureB和ompll基因并用重叠延伸PCR法获得ureB-ompl1融合基因，将融合基因ureB-ompl1插入原核表达载体pET30a（＋）、pET28a（＋）及pMAL-c2X中，筛选出合适的表达系统并进行融合蛋白的表达，采用Westernblot对表达产物进行鉴定，并用Amylose亲和层析法纯化融合蛋白，应用SDS-PAGE方法对纯化产物进行分析，纯化的融合蛋白辅以免疫佐剂皮下免疫小鼠，Westernblot对免疫小鼠血清进行检测。结果：特异PCR法、酶切鉴定并经测序分析后证实融合基因ureB—ompll克隆人表达载体pE330a（＋）、pET28a（＋）与pMAL—c2X中；重组菌TBl（pMAL-ureB—ompl1）经诱导获得了高效表达的MBP-UreB—Ompll融合蛋白，该融合蛋白可以被却免疫小鼠血清和却阳性患者血清中的相应抗体所识别，纯化后的融合蛋白纯度达90％以上。通过大肠杆菌抗原吸收法纯化免疫小鼠血清后，与纯化的融合蛋白进行杂交，结果显示在M，134000处出现特异杂交带，融合蛋白具有良好的免疫原性和免疫反应性。结论：成功地构建并筛选出了却MELHP27融合蛋白UreB-Ompl1的重组疫苗候选株TBl（pMAL-ureB—ompll），为坳蛋白质疫苗和核酸疫苗的研制奠定了基础。     

重组流感病毒H1N1活菌疫苗的构建及其免疫效果的初步研究

目的获得两种流感病毒重组沙门氏菌X4550(asd-pVAX1-HA)和X4550(asd-pVAX1-NA)活菌疫苗,并对其免疫效果进行初步的研究。方法将本室已构建好的重组质粒pVAX1-HA及pVAX1-NA双酶切后得到HA、NA基因,将其克隆入asd-pVAX1构建重组的表达质粒。将重组质粒转染COS-7细胞,用免疫细胞化学方法鉴定重组质粒体外的表达。进一步将重组质粒转化减毒鼠伤寒沙门氏菌X4550,以2×109CFU/只的剂量三次口服免疫Balb/c小鼠。结果asd-pVAX1-HA和asd-pVAX1-NA均能在COS-7细胞中表达;免疫小鼠不仅可以检测到HA、NA特异性的血清IgG及IgA抗体;刺激黏膜免疫反应,产生sIgA抗体,而且能抵抗40LD50同型病毒滴鼻的攻击。结论H1N1流感病毒DNA疫苗的减毒沙门氏菌运送系统在体内能够成功释放所携带的质粒,并且能够刺激机体产生保护性免疫应答。     

恶性疟原虫裂殖子表面蛋白1羧基端编码基因真核表？…

构建以恶性疟原虫红内期重要的疫苗候选抗原－裂殖子表面蛋白羧基端编码分子量４２０００蛋白的基因片段为外源基因的可用作候选核酸疫苗的真核表达载体。方法目前对疟疾核酸疫苗的研究仅见于鼠疟，将恶性疟原虫ＦＵＰ株裂殖子表面蛋白１羧基端编码４２０００蛋白的基因片段用常规分子克隆方法，分别克隆入非分泌性真核表达载体ＶＲ１０１２和改建后的分泌型载体ＶＲ１０１２／ＴＡ中，通过ＰＣＲ和酶切鉴定出重组克隆。     

SARS病毒N蛋白的表达与DNA疫苗的构建

目的：在大肠杆菌中表达SARS冠状病毒核衣壳N蛋白，并构建其DNA疫苗。方法：构建含N基因的原核表达载体pQEN，并在大肠杆菌M15中表达N蛋白。采用NP亲和层析法纯化目的蛋白。将N基因克隆入真核表达载体pSecTagB中，构建真核重组质粒pSecN。以其免疫小鼠制备抗血清，并用ELISA法检测其与大肠杆菌中表达的重组N蛋白及天然全病毒N蛋白的反应性。结果：重组N蛋白能与DNA疫苗免疫的小鼠血清以及SARS患者血清发生特异性反应；SARS—CoV病毒颗粒也可与DNA疫苗免疫的小鼠血清发生特异性反应。结论：重组N蛋白保留了病毒的一些特异性抗原表位，可作为用ELISA法检测SARS—CoV的抗原。构建的DNA疫苗可在小鼠体内产生高效价的抗SARS病毒N蛋白的特异性抗体，从而为该疫苗的开发奠定了基础。     

布氏杆菌pCDNA3.1-L7/L12核酸疫苗的构建及其免疫学评价

目的 获得布氏杆菌保护性抗原L2／L12重组蛋白及pCDNA3．1-L7／L12重组质粒，并比较其诱导特异性免疫应答的能力。方法 PCR扩增布氏杆菌核蛋白L7／L12基因分别构建至原核表达载体PET32a( )和真核表达载体pCDNA3.1( )中；pET32a-L7／L12重组质粒转化BL21(DE3)，所表达蛋白经SDS-PAGE、免疫印迹分析、纯化后免疫小鼠；pCDNA3.1-12／L12重组质粒配以GM-CSF同时肌肉注射免疫小鼠，3次免疫后测定免疫功能进行免疫效果的评价。结果ELISA、Western blot检测到免疫鼠体内有特异性抗体产生，蛋白苗所诱导的抗体效价远远高于DNA疫苗；通过淋巴细胞增殖实验、细胞因子和CD分子测定表明DNA疫苗以诱发TH1型免疫为主。结论 所构建的布氏杆菌DNA疫苗和蛋白苗均具有诱导特异性细胞和体液免疫应答的能力，DNA疫苗诱导产生的细胞免疫反应强于蛋白苗，可作为潜在的布氏菌新型疫苗，有进一步研究的意义。     

利用减毒沙门菌递送的柯萨奇病毒A16型VP1基因重组质粒的构建和鉴定

目的:构建能够稳定携带柯萨奇病毒A16型(CoxA16)VP1基因的重组减毒伤寒沙门菌并鉴定目的抗原的表达,研发利用减毒沙门菌递送的口服疫苗.方法:利用DNA重组技术,构建表达CoxA16 VP1蛋白的真核表达质粒,体外转染Vero细胞后检测VP1蛋白表达情况及抗原活性,并将该质粒通过电转化构建重组减毒伤寒沙门菌.结果:构建了表达CoxA16 VP1蛋白的重组质粒,转染vero细胞后检测到CoxA16 VP1蛋白的表达并具有抗原活性;获得能稳定携带该质粒的重组减毒伤寒沙门菌.结论:成功构建稳定携带柯萨奇病毒A16型(CoxA16)VP1基因的重组减毒伤寒沙门菌,为口服CoxA16疫苗的研究打下了基础.     

以减毒沙门菌为载体布鲁氏菌DNA疫苗的构建及免疫原性分析

目的 构建携带布鲁氏菌BLS-L7/L12融合基因的重组减毒沙门菌并进行免疫原性分析,为口服布鲁氏菌DNA疫苗研究奠定基础.方法将BLS-7/L12融合基因克隆到真核表达载体asd -pVAX1,依次将重组质粒转化减毒沙门菌X3730、X4550得到重组沙门菌X4550(asd -pVAX1-BLS-L7/L12).以1×109CFU/只的剂量口服免疫Balb/C小鼠,3次免疫后进行免疫效果的评价.结果构建的重组减毒沙门菌质粒转染COS-7细胞经免疫组化和Western-blot试验证明BLS-L7/L12融合蛋白在细胞中得到了瞬时表达,ELISA检测到免疫小鼠血清和肠黏液中有特异性抗体IgG和sIgA产生.通过淋巴细胞增殖实验、细胞因子和CD分子测定表明DNA疫苗以诱发Th1型免疫为主.结论 所构建的以重组沙门菌为载体口服布鲁氏菌DNA疫苗具有诱导特异性细胞免疫和体液免疫应答的能力,且以细胞免疫应答为主.可作为潜在的布鲁氏菌新型疫苗.     

Hybrid hepatitis B virus core-pre-S proteins synthesized in avirulent Salmonella typhimurium and Salmonella typhi for oral vaccination.

Avirulent salmonellae expressing foreign genes are attractive for use as oral vaccine carriers. To facilitate the stable expression of heterologous genes without conferring antibiotic resistance, a deletion of the asdA1 gene was introduced into Salmonella typhimurium and S. typhi delta cya delta crp mutant vaccine strains. An asd-complementing plasmid expressing hybrid hepatitis B virus nucleocapsid-pre-S (HBcAg-pre-S) particles was constructed. These hybrid HBcAg-pre-S particle genes were stably expressed in S. typhimurium and S. typhi delta cya delta crp mutant vaccine strains in this balanced, lethal host-vector combination. A single oral immunization of BALB/c mice with a recombinant S. typhimurium delta cya delta crp mutant synthesizing hybrid HBcAg-pre-S elicited potentially virus-neutralizing anti-pre-S serum immunoglobulin G antibodies. In addition, serum immunoglobulin G recognizing S. typhimurium lipopolysaccharide was induced. Distribution in tissue after oral immunization was analyzed in one plasmid-strain combination. The recombinant S. typhimurium colonized the gut-associated lymphoid tissue and the spleen and persisted for over 4 weeks, retaining the HBcAg-pre-S expression plasmid. An isogenic virulence plasmid-cured S. typhimurium delta cya delta crp strain expressing the same HBcAg-pre-S gene had reduced immunogenicity for the carried antigen after oral immunization.     

Oral immunization with recombinant Salmonella typhimurium expressing surface protein antigen A of Streptococcus sobrinus: persistence and induction of humoral responses in rats.

Recombinant Salmonella typhimurium has been used as an oral vaccine for various microbial pathogens. Here we report immune responses in Fischer rats orally immunized with a recombinant S. typhimurium strain encoding surface protein antigen A (SpaA) of Streptococcus sobrinus. The attenuated S. typhimurium chi 4072 delta cya delta crp delta asd mutant used in this study contains the Asd+ plasmid pYA2905 expressing a fragment of the SpaA protein. Salmonella cells were cleared from spleens by 7 days and from Peyer's patches by 14 days in rats receiving a single oral immunization of 10(9) CFU of chi 4072. In animals receiving multiple (i.e., days 0 and 7 or days 0, 7, and 21) immunizations, Salmonella cells were cleared from the Peyer's patches by 25 days following the initial immunization. Antigen-specific systemic and mucosal antibody responses were greater in rats receiving multiple immunizations than in those receiving a single immunization. Serum anti-Salmonella activity was potentiated following boosting on day 21. Mucosal immunoglobulin A antibody responses were also greater in rats receiving multiple immunizations than in rats receiving a single immunization. Anti-Salmonella and anti-Streptococcus immunoglobulin A activity persisted longer in rats boosted on day 21 than in rats immunized on days 0 and 7. These data indicate that oral immunization of rats with the recombinant S. typhimurium chi 4072(pYA2905) vaccine induces systemic as well as mucosal antibody responses specific to the Salmonella cells and to the cloned SpaA protein. This is the first report of the use of an attenuated mutant of the murine pathogen S. typhimurium as an oral vaccine in rats.     

沙眼衣原体主要外膜蛋白在减毒鼠伤寒杆菌中的表达及 …

目的 采用作为疫苗载体的减毒鼠伤寒杆菌致死性平衡系统,构建能异源表达沙眼衣原体（Ｃｔ）主要外膜蛋白（ＭＯＭＰ）的重组菌株。方法 以Ｄ型Ｃｔ的ＤＮＡ为模板,用所设计的特异性引物扩增编码Ｃｔ ＭＯＭＰ高变区（ＶＤＩ～ＶＤＩＶ）基因,并将扩增产物定向克隆至质粒ｐＵＣ１９中。序列分析后,再亚克隆至与减毒鼠伤寒杆菌Ｘ４５５０互补的质粒ｐＹＡ３３４１中,以重组质粒转化减毒鼠伤寒杆菌Ｘ４５５０。结果 对构建的重     

Resistance and susceptibility of mice to bacterial infection: course of listeriosis in resistant or susceptible mice.

Within 3 h after oral challenge of mice with Salmonella typhimurium, foci of infection developed in the Peyer's patches of the small intestine. The numbers of organisms in the cecum, although in excess of those found in the small intestine, were not firmly associated with the cecal wall but were present largely in the cecum's contents. The Peyer's patches at first were remarkably incapable of eliminating even small numbers of Salmonella, but at about 7 days after infection developed the ability to eliminate a less virulent strain of S. typhimurium. Selected strains of Salmonella of varied virulence, and hybrid Escherichia coli/Salmonella typhimurium with varied O-antigens, revealed that those of low virulence could multiply within the intestinal Peyer's patches at nearly the same rate as a virulent strain, and the ability to multiply within the Peyer's patches was not dependent upon O-antigen type or smooth lipopolysaccharide. The ability of these strains to adhere to intestinal mucosa in vitro did not reflect on their ability to colonize the Peyer's patches, although strains of high in vitro adhesive ability appeared in greater numbers initially after oral challenge. Anti-O serum, ineffective in reducing the in vitro adhesive ability of virulent S. typhimurium, when given with the oral challenge prevented Peyer's patch colonization but was unable to prevent the appearance of a systemic infection. Anti-H serum, although effective in vitro in preventing adherence, had no effect in vivo. These experiments suggest that adhesiveness is neither essential nor sufficient for the virulence of Salmonella and that the usual development of a systemic infection after colonization of the small intestinal Peyer's patches may be subverted by the presence of O-antibody.     

表达幽门螺杆菌hpaA重组减毒鼠伤寒沙门氏菌的构建和鉴定

目的：构建表达幽门螺杆菌（H.pylori)hpaA的重组减毒鼠伤寒沙门低 疫苗菌。方法：用基因工程的方法将hpaA基因克隆入原核表达质粒pTrc99A,并进行了基因测序。重组质粒经鉴定后再导入减毒鼠伤寒沙门氏菌SL3261,提取重组疫苗菌质粒,PCR和酶切鉴定,筛选阳性克隆。用SDS－PAGE电泳和Western blot进行HpaA表达和鉴定。结果：经PCR和酶切证实,构建了含hpaA的重组原核表达质粒pTrc99A-hpaA,并将后者成功转化了减毒鼠伤寒沙门氏菌。HpaA能在疫苗菌中以二聚体形式表达,HpaA量约占全菌体蛋白量的17％,Westem blot证实其有免疫原性。结论：构建了表达H.pylori hpaA的重组减毒鼠伤寒沙门氏疫苗菌,为探索制备H.pylori口服活疫苗尊定了基础。     

表达肠出血性大肠杆菌 O157:H7 EspA 抗原的减毒沙门氏菌株的构建

目的 利用平衡致死系统构建表达O157:H7 EspA 的减毒鼠伤寒沙门氏菌.方法 构建表达EspA的重组质粒,再将其转入终宿主菌减毒鼠伤寒沙门氏菌x4550 株中构建成口服活疫苗株,用IPTG进行诱导表达,经聚丙烯酰胺凝胶电泳、Westen-blot检测EspA蛋白的表达情况.并观察重组菌体外培养的稳定性.结果 利用宿主-载体平衡致死系统构建了表达O157:H7 EspA的重组减毒沙门氏菌,经Tricine-SDS-PAGE电泳出现了1条Mr约21 000的蛋白条带,Westen-blot检测能与抗EspA的单克隆抗体发生特异性反应.且在没有选择压力的条件下体外能稳定地繁殖、生长和传代.结论 表达O157:H7 EspA的重组减毒沙门氏菌构建成功,为发展口服抗EHEC O157:H7的疫苗奠定了初步基础.