含有丙型肝炎病毒核心基因表达质粒的构建及其基因免疫

目的：研究丙型肝炎病毒（ＨＣＶ）核心（Ｃ）基因免疫诱生特异性免疫应答的可行性。方法：将ＨＣＶ Ｃ基因片段插入真核表达载体ｐｃＤＮＡ３质粒ＣＭＶ启动子的下游,构建真核表达载体ｐｃＤＮＡＨＣＶ－Ｃ,分别转染小鼠骨髓瘤细胞ＳＰ２／０和人肝癌细胞７７２１进行瞬时表达,用免疫荧光法和Ｗｅｓｔｅｒｎ－ｂｌｏｔ检测表达产物,将重组质粒注射,ＢＡＬＢ／ｃ（Ｈ－２＾ｄ）小鼠股四头肌,ＥＬＩＳＡ法检测血清中抗体产生水     

DNA mediated immunization with encoding the nucleoprotein gene of porcine transmissible gastroenteritis virus

The immune response to a naked plasmid DNA encoding the nucleoprotein (N protein) of porcine transmissible gastroenteritis virus (TGEV) was investigated in this study. A complementary DNA of the entire N gene was amplified by RT-PCR, and inserted into a mammalian expression vector (pcDNA3.1) to construct a recombinant plasmid (pcDNA/N). To evaluate the immunogenicity of the construct, BALB/c mice were intramuscularly immunized with different doses (50, 100 and 200 μg/mouse) of pcDNA/N twice at a 5-week interval. An optimal antibody response was achieved with 100 μg of pcDNA/N. The response lasted at least 11 weeks after primary immunization. By western blotting analysis, the antibodies specifically recognized a 47 kDa protein corresponding to the viral N protein, but they did not reveal neutralizing activity against infectious TGEV in vitro. Immunoglobulin G2a was predominant among these antibodies, which was indicative of Th1 type cell activation in pcDNA/N immunized mice. Moreover, spleen cells from these mice showed stronger immune responses than those from live vaccine or parental vector immunized mice. These results suggest that the construct can elicit both humoral and cell-mediated immune (CMI) responses against TGEV N protein in mice.     

不同免疫方案制备抗HAb18G/CD147胞外区多克隆抗血清的比较

目的: 制备针对肝癌相关抗原HAb18G/CD147胞外区不同表位的抗血清, 比较不同免疫方案的免疫效果。方法: 以原核表达的GST -HAb18GEF融合蛋白、重组真核表达质粒pcDNA3 /HAb18G及HCC细胞为免疫原, 分别采用蛋白常规免疫、DNA肌肉免疫及pcDNA3 /HAb18G -HCCbooster(DNA -cellbooster)免疫接种BALB/c小鼠。采用间接ELISA和细胞ELISA, 同时测定免疫血清中抗变性和天然HAb18GEFIgG抗体的滴度和Ig亚类。用Westernblot检测各免疫方案制备的抗血清, 与变性HAb18GEF抗原结合的特异性。用免疫荧光法验证DNA- cellbooster免疫接种法制备的抗血清, 与细胞膜上天然HAb18G抗原的结合特异性。结果:以GST- HAb18GEF常规免疫后, 可诱导高滴度的IgG1抗体产生, 但针对的多为HAb18GEF的变性或线性表位; 以pcD -NA3 /HAb18G肌肉免疫后, 可诱导针对其天然表位的IgG2a抗体产生, 但滴度较低; 以DNA -cellbooster免疫后, 可诱导中等滴度、针对其天然表位的IgG2a和IgG1抗体产生。结论: 不同免疫方案可诱导针对HAb18GEF不同表位、不同滴度的多克隆抗血清, 为淘筛针对其不同表位的多样性抗体奠定了基础。     

C3d对基因免疫诱导的HBV特异性体液免疫应答的调节作用

观察补体C3d对HBV基因免疫诱导的特异性体液免疫应答的调节作用 ,为增强HBV基因疫苗免疫效果寻求新途径。将HBV preS2 /S编码基因分别插入真核表达载体TR4 2 1和含有 3拷贝C3d编码基因的TR4 2 1 C3d3质粒 ,构建重组质粒TR4 2 1 preS2 /S和TR4 2 1 preS2 /S C3d3。采用肌肉注射法对BALB/c小鼠实施基因免疫 (10 0 μg/ 10 0 μl/只小鼠 ) ,以空质粒为对照 ,定期采集血清。ELISA法检测免疫小鼠血清特异性抗 HBs IgG及其亚型 ,并采用NaSCN竞争ELISA法检测其亲合力。结果表明 ,TR4 2 1 preS2 /S C3d3重组质粒免疫组诱导的特异性抗 HBs IgG水平明显高于TR4 2 1 preS2 /S重组质粒免疫组 (P <0 0 5 ) ;而且TR4 2 1 preS2 /S C3d3重组质粒免疫组诱导的抗 HBs IgG抗体的亲合力 (ED50 :1 375 )显著高于TR4 2 1 preS2 /S重组质粒组 (ED50 :0 875 ) ,但C3d并不改变基因免疫诱导的特异性抗HBs IgG各亚型水平的格局 ,仍以IgG2b和IgG2a为主。提示C3d可增强基因免疫诱导的HBV特异性体液免疫应答 ,并促进特异性抗体亲和力的成熟 ,这为提高HBV基因疫苗的免疫效果提供了新的途径。     

SARS冠状病毒S基因重组DNA诱导的体液免疫反应

目的 以严重急性呼吸综合征冠状病毒（SARS-CoV）密码子优化的S、S1和S2基因分别构建其真核表达质粒，免疫BALB／c小鼠，以初步评价其诱导特异性体液免疫的效果。方法将人工合成密码子优化的S、S1和S2基因克隆入pcDNA4／HisMax-TOPO表达载体，重组质粒转染293T细胞，Western blot和免疫组化检测其真核表达，重组质粒免疫BALB／c小鼠，酶联免疫（ELISA）检测抗S蛋白抗体，伪病毒中和试验、细胞融合抑制试验检测中和抗体。结果3种重组质粒均可在真核细胞中获得表达，免疫小鼠后可诱导针对S蛋白的特异性抗体，抗体在12周观察期内呈持续上升趋势；其中，仅S和S1蛋白重组质粒能够诱导中和抗体的产生，以S蛋白的效价为高。结论密码子优化S和S1蛋白重组质粒可以有效诱导BALB／c小鼠产生中和抗体，其抗体可能具有阻断SARS-CoV侵袭易感细胞的能力。该结果为进一步研究SARS-CoV DNA疫苗提供了参考依据。     

C3d-P28增强乙型肝炎病毒特异性基因免疫效果的研究

目的　观察补体C3d P2 8对基因免疫的调节作用及其不同拷贝数对调节作用的影响 ,为增强基因免疫效果寻求新方法。方法　PCR法获得补体C3d P2 8编码基因并以头尾串连方式将1～ 4拷贝C3d P2 8编码基因克隆至pVAON33,构建pVAON33 P2 8.[1～ 4 ]重组质粒 ,然后将HBV preS2 S编码基因分别插入pVAON33和pVAON33 P2 8.[1～ 4 ]质粒获得pVAON33 S2 S和pVAON33 S2 S P2 8.[1～ 4 ]重组质粒。肌肉注射各重组质粒DNA(每只 10 0 μg 10 0 μl)初次免疫小鼠 ,并以pVAON33为对照 ;12周后皮下注射HBsAg蛋白加强免疫各组小鼠 ,ELISA法检测免疫小鼠血清特异性抗 HBs IgG。结果　pVAON33 S2 S重组质粒免疫小鼠可诱导产生特异性抗 HBs IgG ,含不同拷贝C3d P2 8编码基因的重组质粒可诱导更高的特异性抗体 ,其中pVAON33 S2 S P2 8.4重组质粒诱导的抗体水平最高 (P <0 .0 1)。蛋白加强免疫后 ,含C3d P2 8编码基因重组质粒免疫组抗 HBs IgG迅速上升 ,并明显高于pVAON33 S2 S重组质粒免疫组 (P <0 .0 5 ) ,pVAON33 S2 S P2 8.4重组质粒诱导的抗体仍维持最高水平。结论　不同拷贝的C3d P2 8能不同程度地增强HBV preS2 S基因免疫诱导的特异性体液免疫及其蛋白加强后的回忆反应 ,其中 4拷贝C3d P2 8的增强作用较为显著。     

免疫途径及载体对乙肝病毒DNA疫苗免疫效果影响的研究

目的探讨ＤＮＡ载体结构及接种途径对ＤＮＡ疫苗免疫效果的影响。方法分别构建插入ＨＢＶ表面抗原编码基因的表达载体ｐｃＤＮＡ１．１／ＳＡ（无抗性基因）和ｐｃＤＮＡＩ／Ａｍｐ／ＳＡ（含氨苄青霉素抗性基因）,肌注小鼠后比较其诱生特异性免疫应答的能力;同时比较不同接种途径（肌内、皮内、皮肤划痕）及ＣｐＧ免疫刺激元件（ＩＳＳ）对ＤＮＡ疫苗诱生免疫效果的影响。结果ｐｃＤＮＡＩ／Ａｍｐ／ＳＡ的免疫效果优于ｐｃＤＮＡ１．１／ＳＡ。ｐｃＤＮＡ１．１／ＳＡ的免疫效果可被ＩＳＳ增强,而ｐｃＤＮＡＩ／Ａｍｐ／ＳＡ诱生特异性免疫应答的能力则可被ＩＳＳ抑制;诱生免疫应答的能力以肌内注射最强,皮内注射免疫其次,皮下划痕法较弱。结论不同ＨＢｓＡｇ表达载体诱生免疫应答的能力不尽相同;ＣｐＧ免疫刺激元件在决定ＤＮＡ疫苗免疫原性中起重要作用,可增强不含相应结构ＤＮＡ疫苗的免疫效果;皮内注射可诱发与肌内接种相似的免疫应答,是一种简便、有效的免疫接种途径     

Production of a monoclonal antibody against SARS-CoV spike protein with single intrasplenic immunization of plasmid DNA

Severe acute respiratory syndrome (SARS) is a highly infectious disease caused by a novel coronavirus (SARS-CoV). Specific monoclonal antibodies (mAbs) against the SARS-CoV are vital for early diagnosis and pathological studies of SARS. Direct intrasplenic inoculation of plasmid DNA encoding antigen is an effective and fast approach to generate specific mAb when the protein antigen is difficult to prepare or dangerous in use. In this study, we selected one fragment of SARS-CoV spike protein (S1-₃) as antigenic determinant by immunoinformatics. Single intrasplenic immunization of plasmid DNA encoding S1-₃ induced anti-spike protein antibodies. We established one hybridoma cell line secreting specific mAb and evaluated this mAb with murine leukemia virus pseudotyped with SARS-CoV spike protein (MLV/SARS-CoV). The mAb could recognize the spike protein on the MLV/SARS-CoV-infected Vero E6 cells albeit with no neutralizing effect on the infectivity of the pseudotype virus. Our results show that a single-shot intrasplenic DNA immunization is efficient for the production of specific mAb against SARS spike protein, and a linear epitope of the spike protein is recognized in this study.     

两株登革2型病毒E基因重组质粒免疫BALB/c小鼠产生特异性抗体水平的比较

目的 用含登革2型病毒(Dengue type 2 virus,DEN2)B株和NGC株E基因部分序列pcDNA3.1重组质粒初次和加强免疫BALB/c小鼠,观察免疫小鼠体液免疫应答的差异.方法 用两株含DEN2 E基因部分序列(1～476 bp)的pcDNA3.1重组质粒与含有佐剂的重组质粒共同免疫BALB/c小鼠,初次免疫后第14天、28天分别加强免疫1次,共免疫3次.收集初次免疫后第14、28、42、70和98天外周血标本,间接ELISA法测定小鼠血浆特异性IgM/IgG类抗体水平,细胞病变抑制法检测特异性抗体水平.结果 不同DEN2毒株E基因部分序列的pcDNA3.1重组质粒初次和加强免疫BALB/c小鼠诱导特异性IgM、IgG类抗体的产生存在差异,B株重组质粒加强免疫小鼠后特异性抗体效价水平较高并持续较长时间.结论 DEN2两毒株E基因部分序列重组质粒免疫小鼠后诱生的特异性抗体类别、水平存在差异.     

以DNA免疫和细胞抗原加强制备抗DAF单克隆抗体及特性分析

目的:联合应用DNA免疫和细胞抗原加强制备抗DAF单克隆抗体(mAb)并鉴定其特性。方法:利用分子克隆的方法构建重组质粒pcDNA3.1/DAF。以其免疫BALB/c小鼠股四头肌3次,并在融合前用表达DAF分子的HPB-ALL细胞为抗原加强免疫1次,制备抗DAFmAb。以ELISA法测定mAb的Ig亚类。采用流式细胞术和Westernblot鉴定mAb的特异性和结合活性。以非免疫竞争法测定mAb的亲和常数。结果:成功地获得2株可识别DAF分子不同抗原表位的mAbB6E和2B6B,其Ig亚类均为IgG2a。mAb2B6E的亲和常数为1.81×10-7mol/L,与天然的细胞膜蛋白、变性的膜蛋白以及重组DAF蛋白都有良好的结合活性和特异性。结论:先以pcDNA3.1/DAF肌肉内免疫,再应用细胞抗原加强免疫的方法制备特异性的mAb,为在无法获得纯化蛋白质的情况下开拓了研制特异性抗体的新途径,也为日后改造抗DAFmAb进行靶向治疗研究打下了基础。     

pcDNA3.1+/MAGE-3 DNA疫苗诱导特异性抗肿瘤免疫应答的实验研究

目的：构建pcDNA3.1+/MAGE-3 DNA疫苗，观察其在小鼠体内诱导特异性抗肿瘤免疫应答的能力。方法： 通过RT-PCR构建重组表达质粒pcDNA3.1+/MAGE-3；以pcDNA3.1+/MAGE-3 DNA疫苗免疫已接种肿瘤细胞的小鼠，每10 d重复免疫1次，共3次，以pcDNA3.1+、PBS为对照。末次免疫后5 d检测血清中MAGE-3抗体滴度、小鼠脾淋巴细胞的细胞毒T细胞（cytotoxic T lymphocytes，CTL）杀伤活性、细胞因子IL-2和IFN-γ的浓度，同时计算抑瘤率。结果： 成功构建了pcDNA3.1+/MAGE-3 DNA疫苗，用此疫苗免疫已接种B16/MAGE-3细胞的小鼠后，能诱导小鼠脾淋巴细胞MAGE-3特异性的杀伤活性，脾细胞培养上清中细胞因子IL-2和IFN-γ的浓度明显增高，血清中抗MAGE-3抗体在1∶20滴度时阳性，肿瘤生长被显著抑制，与pcDNA3.1+组、PBS组相比，差异显著（P＜0.01）。结论： 成功构建了pcDNA3.1+/MAGE-3 DNA疫苗，该疫苗在小鼠体内既能激活CTL杀伤活性和CD4+ T细胞活性，又能激活体液免疫反应，从而诱导出特异性的抗肿瘤免疫应答。     

利用DNA免疫法制备植物选择标记基因hpt表达蛋白抗体的研究

目的：制备转基因作物中选择标记基因——潮霉素B磷酸转移酶(hygromycin B phosphotransferase，hpt)基因表达产物的多克隆抗体，并探讨影响核酸免疫效果的因素及相应机制。方法：以hpt的cDNA全长插入真核表达载体pcDNA3中，并经限制性内切酶酶切及DNA测序鉴定。以纯化的重组质粒pCDNA3-HPT免疫BALB／c小鼠。用在E．coli中表达并纯化的(His)6—HPT进行ELISA，检测免疫过程中小鼠血清抗体效价的增长状况，并用Western blot检测抗血清的特异性。结果：经3次核酸免疫后，小鼠血清中未发现明显的抗HPT抗体一第4次加强免疫时，将小鼠分为3组，每组两只。第1组改用去内毒素的质粒提取试剂盒提纯的重组质粒免疫，第2组用(His)6-HPT融合蛋白免疫，第3组仍用原来提取的重组质粒免疫。结果发现，第1组小鼠抗血清的效价有所上升，经ELISA检测达1：200；第2组抗血清的滴度显著升高，达到1：2000；而第3组小鼠血清中仍未检测到明显的抗体：Western blot证实，前两组抗血清均可与亲和层析纯化的GST—HPT、(His)6-HPT融合蛋白及其诱导表达的相应菌体总蛋白发生特异性结合。结论：用DNA免疫法成功地制备了抗hpt基因表达产物的特异性抗体，但抗体效价不够理想。推测与hpt基因本身的性质及其在体内表达呈现的水平有关，可望通过州整影响核酸免疫的其他多种因素提高抗体的水平。     

SARS冠状病毒S蛋白C端片段基因的克隆及其DNA疫苗的免疫学研究

目的：构建抗原基因为SARS冠状病毒（Severe acute respiratory syndrome coronavirus，SARS-CoY）S蛋白C端片段基因的DNA疫苗，采用肌注和滴鼻的方法接种小鼠后观察肌肉注射途径和黏膜途径免疫使机体产生免疫应答的情况。方法：将S蛋白C端片段克隆至真核表达载体pcDNA3．1（-），随之将重组质粒进行小鼠肌肉和黏膜免疫，定期检测外周血中抗SARS-CoV的病毒特异性抗体水平，流式细胞仪观察其淋巴细胞表型变化，免疫组化检测抗原表达分布，脾细胞增殖实验评价CTL效果。结果：疫苗注射后15天就能在血清中检测出病毒特异性抗体。随着时问的延续，抗体水平逐步升高，至30天后达到稳定，以CTL为主的CD8^＋T淋巴细胞的百分比含量增加极显著，引起强大的体液免疫和细胞免疫；疫苗滴鼻后45天可在鼻黏膜检测到抗原表达；而空载体质粒对照组未检测出明显的特异性免疫应答。结论：以S蛋白C端片段基因为抗原基因的DNA疫苗通过肌注和滴鼻能诱导小鼠针对SARS病毒强大的免疫应答。     

优化密码对牛乳头瘤病毒L1基因粘膜免疫的增强作用

为探讨优化密码对牛乳头瘤病毒 1型主要晚期基因 (BPV1L1)免疫原性的影响 ,分别将含野生型和优化密码的人源化BPV1L1基因的真核表达质粒转入减毒沙门菌S BRD5 0 9后 ,通过滴鼻、阴道免疫、静脉注射、腹腔注射等途径免疫小鼠 ,经VLPELISA方法测定抗L1构象性抗体产生 ,MTT法观察诱导的特异性细胞免疫反应。抗体检测结果显示 ,经粘膜免疫途径 ,与含有野生型L1基因的表达质粒pcDNA3WBPVL1相比 ,含优化密码L1基因的pcDNA3HBPVL1诱导产生的SIgA、IgG明显升高 ,而细胞免疫反应无明显差异。表明优化密码能促进乳头瘤病毒晚期基因L1诱导的体液免疫反应 ,减毒沙门菌是PVL1DNA疫苗粘膜免疫的有效载体。     

Co-delivery of GM-CSF gene enhances the immune responses of hepatitis C viral core protein-expressing DNA vaccine: role of dendritic cells.

Hepatitis C virus (HCV) infection has become a critical public health problem worldwide. In Taiwan, it has been estimated that more than 300,000 people, 2% of the general population, have HCV infection. It has been well documented that direct delivery of gene intramuscularly can generate both humoral and cellular immunity, which more closely simulates the conditions of infection. In this study, female Balb/c mice immunized with HCV core plasmid DNA with or without adjuvant GM-CSF cytokine gene could induce both cellular immune response and HCV core-specific antibody titers after injection. Furthermore, the mice immunized with HCV core plus GM-CSF genes showed higher antibody titer and cytotoxic T cell activity compared to those of mice immunized with HCV core gene only (P < 0.05). To explore the effect of GM-CSF gene, the mice were immunized with reporter gene and cytokine gene plasmid. Increased levels of reporter protein and infiltrating cells around muscle tissue were noted. Moreover, the protein could be detected in inguinal node 24 hr after injection, especially in mice immunized with HCV/core plasmid plus GM-CSF gene. It was also observed that reporter protein expressing CD11c(+) dendritic cells could be seen in the inguinal node. These data suggest that the GM-CSF gene did enhance HCV core specific immune response when co-immunized with HCV core DNA plasmid. Although more studies are needed, dendritic cells that appeared around the naked DNA injection area and that local lymph nodes might play a critical role in the immune response induced by naked DNA immunization.     

两株登革2型病毒NS1基因真核重组质粒免疫BALB/c小鼠产生特异性抗体水平的比较

目的 利用登革2型病毒(dengue type 2 virus,DENV2)M株和NGC株NS1基因部分扇列PcDNA3.1重组质粒初次和加强免疫BALB/c小鼠,观察免疫小鼠体液免疫应答的差异.方法 分别构建两株DENV2 NS1基因部分序列(1-413 bp)的PcDNA3.1真核重组质粒和pET28a(+)质粒,进行原核蛋白的表达、鉴定、纯化和定量;并用pcDNA3.1重组质粒免疫BALB/c小鼠,初次免疫及第7天、14天分别加强免疫1次,共免疫3次.收集初次免疫后第7、14、28和56天外周血标本,间接ELISA法测定小鼠血清特异性IgM/IgG类抗体水平,细胞病变抑制法检测特异保护性抗体水平.结果 构建了pET28a(+)-NS1m/pET28a(+)-NS1n原核表达重组质粒,SDS-PAGE分析表明,NS1基因部分序列获得表达,其相对分子质量均约22.3×103;Western blot表明该目的 蛋白可与抗His标签单克隆抗体结合;经Ni柱亲和层析法得到纯度达92%的表达蛋白,对C6/36细胞有毒性,并可用于ELASA检测.不同DENV2毒株NS1基因部分序列的pcDNA3.1重组质粒初次和加强免疫BALB/c小鼠诱导特异性IgM、IgG类和中和抗体的产生存在差异,M株重组质粒加强免疫小鼠后特异性抗体效价水平较高并持续较长时间.结论 DENV2两毒株NS1基因部分序列重组质粒免疫小鼠后诱生的特异性抗体类别、水平存在差异.

Abstract：

Objective To compare the humoral immune response of BALB/c mice immunized by recombinant plasmids PeDNA3.1-M-NS1 and pcDNA3.1-N-NS1.Methods Dengue type 2 virus(DENV2)NS1 gene were constructed two partial sequences(1-413 bp)of the pcDNA3.1 eukaryotic plasmids and pET28a(+)plasmid for prokaryotic expression,identification,purification and quantification.The BALB/c mice were immunized by pcDNA3.1-M-NS1,pcDNA3.1-N-NS1 recombinant plasmids with adjuvant.Each animal received a primary inoculation and two boosts at 1-week intervals.Then the blood samples of BALB/c mice were collected from different experiment groups at day 7,14,28 and 56,respectively after first immunization.The specific IgM/IgG antibodies for NS1 protein in serum were confirmed by indirect ELISA.And then the activities of the specific protective antibody were determined by cytopathic effect inhibition(CPEI).Results Construction of the pET28a(+)-NS1 m/pET28a(+)-NS1n prokaryotic expression plasmid,SDS-PAGE analysis showed that,NS1 gene partial sequence was expressed,both the relative molecular weight of about 22.3×103:Western blot showed that the protein can bind anti-His tag monoclonal antibody;byNi affinity chromatographywith apurity of 92% protein,on the C6/36 cell toxicity,and can be used ELASA detection.The results showed that the levels of specific IgM/IgG antibody and neutralizing antibody activities were increased in pcDNA3.1-M-NS1 booster immunization group than other groups.The result had been observed longer duration of antibody level in peDNA3.1-M-NS1 booster immunization group.Conclusion Humoral immune response were significantly different between pcDNA3.1-M-NS1 and pcDNA3.1-N-NS1 recombinant plasmid immunized mice groups.     

弓形虫多表位DNA疫苗的构建及其免疫保护作用

目的:构建弓形虫多表位DNA疫苗并研究其免疫保护效果.方法:将编码含弓形虫多个T、B细胞表位的6段弓形虫多肽基因,以5个甘氨酸编码基因相间隔相连接,克隆入真核表达质粒pcDNA3.1( )中,构建成多表位弓形虫DNA疫苗.免疫BALB/c小鼠,测定其诱导的特异性抗体水平及T淋巴细胞增殖状况,同时进行弓形虫攻击感染保护实验.结果:成功构建了包含多个弓形虫表位的真核表达质粒pcDNA3.1/T-ME,以其作为DNA疫苗免疫小鼠,可诱导机体产生弓形虫特异性的体液及细胞免疫应答,产生有效的抗弓形虫保护性免疫应答.结论:构建的弓形虫多表位DNA疫苗能诱导机体产生有效的保护性免疫应答,在控制弓形虫感染上具有可行性.     

Production of polyclonal and monoclonal antibodies against CD54 molecules by intrasplenic immunization of plasmid DNA encoding CD54 protein

DNA immunization, in theory, is of great interest as a source of specific antibodies against different antigens. In an attempt to produce polyclonal and monoclonal antibodies against cell surface molecules by using the DNA immunization strategy, intramuscular and intrasplenic routes of DNA injection were compared. Two to five, but not a single, intramuscular DNA immunizations induced anti-CD54 and anti-CD147 antibody production. In contrast, a single intrasplenic immunization of CD54-encoding DNA could induce anti-CD54 antibody production. To produce monoclonal antibody (mAb), spleen cells obtained from an intrasplenic CD54-encoding DNA immunized mouse were fused with myeloma cells using the standard hybridoma technique. A hybridoma secreting specific mAb to CD54 was established. The generated mAb reacted to CD54 protein expressed on transfected COS cells and various cell types, the same as using standard CD54 mAb MEM-111. Our results demonstrated that direct immunization of antigen-encoding DNA into spleen is an effective route for production of both polyclonal and monoclonal antibodies to cell surface molecules. This finding is very useful for the production of antibodies to cell surface molecules where the protein antigen is not available or difficult to prepare, but cDNA encoding the corresponding protein is available.     

空肠弯曲菌pcDNA3.1(-)-peb1A壳聚糖佐剂疫苗对小鼠免疫原性和保护性研究

目的:研究空肠弯曲菌pcDNA3.1(-)-peb1A壳聚糖佐剂疫苗的免疫原性和保护性。方法:健康雄性昆明小鼠分为实验组和对照组。实验组设pcDNA3.1(-)-peb1A组3个剂量和壳聚糖-pcDNA3.1(-)-peb1A组3个剂量;对照组设空载体pcDNA3.1(-)(100μg/100μl)组和生理盐水(NS)组,各组均采用小鼠股四头肌注射法。在第0、10、20天免疫,于每次免疫后第10天采集各组小鼠血清,以间接ELISA法检测血清中特异性IgM、IgG的含量。分离各组小鼠脾淋巴细胞包被细胞培养板,以细胞ELISA法检测小鼠脾淋巴细胞CD20、CD21表达水平。设空肠弯曲菌液灌胃攻击免疫后小鼠,检测肠道分泌液细菌培养数量。结果:裸DNA组和壳聚糖-DNA组各组特异性IgG水平均高于两对照组(P<0.05)。裸DNA组和壳聚糖-DNA组小鼠脾淋巴细胞CD20、CD21表达水平均高于两对照组(P<0.05),壳聚糖-DNA组高于裸DNA组(P<0.05)。肠道分泌液细菌培养结果细菌指数裸DNA组的低于两对照组;佐剂DNA组低于裸DNA组。结论:重组质粒pcDNA3.1(-)-peb1A经肌肉注射免疫小鼠,具有较好的免疫原性和保护作用,壳聚糖能增强pcDNA3.1(-)-peblA的免疫原性,有望成为空肠弯曲菌基因疫苗的候选佐剂。