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1.
扩增了奶牛乳腺炎金黄色葡萄球菌纤粘连结合蛋白A(Fnb A)配体结合区基因,并将其克隆至真核表达载体p VAX1启动子下游,构建成真核表达质粒,通过体外细胞转染试验,运用IFA方法进行抗原性初步确认,所构建的重组DNA疫苗质粒能在真核细胞中表达外源基因并被金黄色葡萄球菌抗体特异性识别。为进一步评价侯选疫苗的免疫原性,进行了BALB/c小鼠免疫试验,分别检测免疫后的ELISA抗体水平、Th1/Th2类细胞因子水平以及T淋巴细胞增殖试验。结果表明,构建的核酸疫苗p VAX1-p Fnb A免疫小鼠后,ELISA抗体水平提高,Th1/Th2类细胞因子含量提升,T细胞增殖能力增强。  相似文献   

2.
为提高牛病毒性腹泻/粘膜病(BVD/MD)核酸疫苗的免疫效力,本实验应用PCR方法扩增BVD病毒(BVDV) E0基因,构建真核表达质粒pVAX1-E0,转染293T细胞,经RT-PCR和western blot分析显示,转染细胞能够瞬时表达E0蛋白.并分别将pVAX1、pVAX1-E0或将pVAX1-E0分别与一种表达细胞因子基因的重组质粒作为佐剂(pVAX1-IL-2、pVAX1-IL-4及pVAX1-IFN-γ)免疫小鼠,采用间接ELISA法检测免疫小鼠BVDV抗体效价,以MTT法检测免疫小鼠脾淋巴细胞的增殖活性.实验结果表明,与pVAX1-E0相比,接种pVAX1-E0/pVAX1-IL-2小鼠血清E0抗体水平及淋巴细胞增殖水平显著提高(p＜0.01),表明细胞因子基因佐剂IL-2能够有效提高BVDV E0核酸疫苗免疫效果,可以刺激小鼠产生良好的免疫应答.  相似文献   

3.
为评价羊口疮病毒(OrfV)B2L、F1L基因融合真核表达质粒pVAX1-B2L-F1L免疫小鼠诱导的体液和细胞免疫应答及IL-2对其免疫作用的影响。本研究将构建的pVAX1-B2L-F1L真核质粒转染MDBK细胞后,采用RT-PCR和间接免疫荧光试验(IFA)检测B2L-F1L融合基因在MDBK细胞中的表达;将pVAX1-B2L-F1L、pVAX1-B2L-F1L+pVAX1-IL-2、pVAX1空载体、生理盐水对照组KM系小鼠通过后腿肌肉注射的方式免疫,采用ELISA方法检测免疫小鼠血清中OrfV特异性抗体以及Th1型(IL-2、IFN-γ)、Th2型(IL-4、IL-6)细胞因子;MTT法检测小鼠脾淋巴细胞增殖反应。结果显示,pVAX1-B2L-F1L重组质粒能够在MDBK细胞中表达;pVAX1-B2L-F1L+pVAX1-IL-2联合免疫组小鼠血清抗体及IL-2和IFN-γ水平均显著高于pVAX1-B2L-F1L组;该联合免疫组小鼠血清IL-4、IL-6细胞因子水平与pVAX1-B2L-F1L组相比差异不显著(p>0.05);该联合免疫组小鼠的脾淋巴细胞增殖水平高于pVAX1-B2L-F1L组(p<0.05)。由此表明,pVAX1-B2L-F1L能够诱导小鼠产生OrfV特异性体液免疫和细胞免疫应答,联合pVAX1-IL-2诱导的免疫反应以细胞免疫应答为主,且能够促进Th1型细胞因子的分泌。本研究为OrfV基因工程疫苗的研制提供了参考依据。  相似文献   

4.
为了检测气肿疽梭菌NanA基因核酸疫苗的免疫效果,在成功构建pVAX1-NanA真核表达重组质粒的基础上将其转染至Vero细胞,通过间接免疫荧光鉴定其表达,并将成功构建的pVAX1-NanA质粒大量提取后免疫Balb/c小鼠,设置pVAX1-NanA核酸疫苗组、pVAX1空载体组和PBS对照组。对小鼠采血并分离血清,用ELISA测定血清中的IgG、IgG1、IgG2a抗体水平和IFN-γ、IL-4细胞因子水平;第3次免疫2周后,用流式细胞仪测定小鼠脾脏中的CD4~+和CD8~+T细胞水平。结果表明,pVAX1-NanA核酸疫苗免疫Balb/c小鼠后,小鼠血清中IgG、IgG1、IgG2a的抗体水平极显著高于pVAX1空载体组和PBS对照组(P0.01);IFN-γ和IL-4细胞因子水平极显著高于pVAX1空载体组和PBS对照组(P0.01);CD4~+、CD8~+T细胞分析表明, pVAX1-NanA免疫组的CD4~+和CD8~+T细胞水平显著高于pVAX1组和PBS对照组(P0.05),pVAX1-NanA核酸疫苗组的CD4~+/CD8~+T细胞比值高于pVAX1空载体组与PBS对照组(P0.05),pVAX1空载体组和PBS对照组之间无显著差异(P0.05)。试验成功制备了pVAX1-NanA核酸疫苗,且pVAX1-NanA核酸疫苗可刺激Balb/c小鼠产生体液免疫和细胞免疫。  相似文献   

5.
构建羊口疮病毒F1L基因的真核表达质粒,并探讨其对小鼠的免疫原性。本试验采用PCR扩增pMD18TF1L克隆质粒的F1L基因并将其克隆至pVAX1载体中,构建真核表达质粒并转染至MDBK细胞,采用RT-PCR和间接免疫荧光检测F1L基因在MDBK细胞中的转录和表达。将构建的pVAX1-F1L、pVAX1空载体、PBS对照通过后腿肌肉注射的方式免疫KM系小鼠,通过间接ELISA、MTT和FACS法对该DNA疫苗的免疫效果进行评价。结果表明,成功构建了真核表达质粒pVAX1-F1L,并能在MDBK细胞中获得较高水平的表达。免疫小鼠后诱导的特异性抗体水平、脾淋巴细胞增殖反应、CD4~+、CD8~+细胞百分比和IL-2、IFN-γ、IL-4细胞因子水平均高于pVAX1组和PBS对照组。因此,制备的重组核酸疫苗免疫小鼠后能够诱导机体产生体液免疫和细胞免疫。  相似文献   

6.
《中国兽医学报》2019,(5):925-930
构建分子佐剂钙网蛋白Cal与弓形虫SAG1基因的真核表达载体,探讨其对小鼠的免疫原性。采用PCR扩增Cal和SAG1基因并将其克隆至Pvax1载体中,构建出重组质粒pVAX1-Cal-SAG1和pVAX1-SAG1。将构建质粒pVAX1-Cal-SAG1、pVAX1-SAG1同空载体pVAX1通过肌肉注射的方式免疫小鼠,通过ELISA、CCK-8法和小鼠攻虫试验对该DNA疫苗的免疫效果进行评价。结果显示:SAG1片段为855 bp,Cal-SAG1片段为1 566 bp,成功构建了真核表达质粒pVAX1-Cal-SAG1、pVAX1-SAG。小鼠免疫后pVAX1-Cal-SAG1诱导的特异性抗体水平、脾脏淋巴细胞增殖反应和IL-4、IL-10、IL-12 p70及IFN-γ细胞因子水平均高于pVAX1组、pVAX1-SAG1和空白对照PBS组。攻虫后,佐剂组小鼠存活时间最长,较空白对照组多存活5 d。本研究表明:制备的重组核酸疫苗免疫小鼠后能够诱导机体产生体液和细胞免疫,分子佐剂Cal可以显著地增强弓形虫表面膜蛋白SAG1的免疫原性。  相似文献   

7.
本研究计划构建能同时表达牛病毒性腹泻病毒（BVDV）和牛传染性鼻气管炎病毒（IBRV）优势抗原基因的重组质粒并研究其免疫效果,旨在为BVD-IBR二联核酸疫苗的研制提供参考。采用PCR扩增目的基因E0及gD并将其依次连接至真核表达载体pVAX1-IRES中,构建pVAX1-E0-IRES-gD重组真核表达载体;将pVAX1-E0-IRES-gD转染至293T细胞中,间接免疫荧光法检测目的基因在细胞中的表达情况;将pVAX1-E0-IRES-gD以不同剂量采用肌内注射的方式接种小鼠,通过抗体水平和细胞因子检测以及脾淋巴细胞增殖试验对该重组质粒的免疫效果进行评价。结果表明,成功构建pVAX1-E0-IRES-gD重组质粒,目的基因在293T细胞内成功表达。在抗体和细胞因子水平以及脾淋巴细胞增殖能力这3个指标,重组质粒组均极显著高于空载体和阴性对照组,高剂量免疫组优于中、低剂量组;另外,高剂量重组质粒免疫组与二联灭活疫苗组相比无显著性差异。结果显示,成功构建了共表达BVDV E0和IBRV gD基因的重组质粒,体外表达检测证明目的蛋白具有良好的反应原性,动物免疫试验证明其能刺激机体产生良好免疫应答。  相似文献   

8.
为研究所构建羊口疮病毒(OrfV)B2L基因DNA疫苗诱导小鼠的免疫应答效果,本研究对pMD18T-B2L质粒进行PCR扩增,克隆B2L片段至pVAX1载体中构建pVAX1-B2L重组质粒,进行酶切和测序鉴定;采用脂质体法将pVAX1-B2L真核表达质粒转染MDBK细胞,RT-PCR和IFA法检测B2L基因在MDBK细胞中的转录和表达;将构建的DNA疫苗免疫KM系小鼠,采用间接ELISA、MTT和FACS法对其诱导的免疫应答进行研究。结果显示,成功构建pVAX1-B2L真核表达质粒,并在MDBK细胞中表达;免疫小鼠后,DNA疫苗能诱导小鼠产生OrfV特异性抗体;脾淋巴细胞增殖、CD4~+、CD8~+T淋巴细胞亚群百分比和IL-2、IFN-γ、IL-4细胞因子均高于pVAX1组和PBS组。结果表明,本研究制备的DNA疫苗能够诱导小鼠产生较高水平的体液免疫和细胞免疫应答。  相似文献   

9.
为评价犬恶丝虫硫氧还蛋白过氧化物酶(TPx)真核表达质粒的免疫原性,本实验利用RT-PCR方法扩增TPx基因,将其克隆于真核表达载体pVAX1中构建重组质粒pVAX1-TPx,并对其进行体外表达鉴定及通过特异性抗体水平及相关的免疫因子的检测,评价其在体内诱导的免疫反应.实验结果表明,将pVAX1-TPx转染于Cos7细胞中能够正确表达TPx,其分子量约为28 ku,并被阳性血清所识别.将pVAX1-TPx免疫BALB/c小鼠并采用ELISA检测结果显示,重组质粒免疫组的外周血中抗体、Th2细胞分泌的IL4及IL13细胞因子水平均显著高于空质粒及空白对照组(p＜0.05);但Th1分泌的IFN-γ及IL2水平差异不显著.此外,淋巴细胞增殖试验结果也表明,pVAX1-TPx免疫组显著高于其他两个对照组(p＜0.05).实验数据表明pVAX1-TPx免疫可以有效诱导特异性的体液和细胞免疫.  相似文献   

10.
为评价猪囊尾蚴副肌球蛋白(AgB)真核表达重组质粒作为候选DNA疫苗的免疫效果,本研究将猪囊尾蚴AgB基因亚克隆于真核表达载体pVAX1中构建了重组表达质粒pVAX1-AgB;将pVAX1-AgB与ISA206佐剂按1:1体积比乳化,以每只100μg的剂量,肌肉注免疫5周龄左右的BALB/c小鼠,3周后加强免疫。同时,通过原核表达制备重组AgB蛋白作为ELISA检测抗原,通过间接ELISA方法检测免疫小鼠的抗体水平。结果显示,在小鼠免疫后2周即可检测到抗AgB抗体,6周达到峰值,并维持在较高水平,持续达8个月;实验组血清抗体水平明显高于对照组(p0.01)。本研究为pVAX1-AgB作为候选DNA疫苗提供了实验依据。  相似文献   

11.
This study was conducted to investigate whether the co-delivery of DNA encoding porcine cytokines would enhance a protective immune response in pigs to a Pseudorabies virus (PRV; or Aujeszky’s disease virus) DNA vaccine. Aujeszky’s disease in pigs results in respiratory and nervous symptoms with important economic losses. To evaluate cytokine effects, eukaryotic expression vectors were constructed for porcine GM-CSF, IL-2 and IFN-γ. cDNA for each of these cytokines was inserted under the control of a CMV promoter in the pcDNA3 plasmid and cytokine expression was confirmed after DNA transfection in various mammalian cell cultures by bioassays (GM-CSF and IL2) and ELISA (IFN-γ). Pigs were vaccinated by single intramuscular injection with plasmid DNA encoding PRV gB and gD along with various combinations of cytokine plasmid constructs. Pig serum was tested for the production of antibody by isotype specific anti-PRV ELISA. Pigs were then challenged with the highly virulent PRV strain NIA3 on day 21 after vaccination. The survival and growth rate of pigs were monitored for seven days after the viral challenge. The co-administration of GM-CSF plasmid increased the immune response induced by gB and gD PRV DNA vaccine. This immune response was characterized by an earlier appearance of anti-PRV IgG2, a significantly enhanced anti-PRV IgG1 and IgG2 antibody response, a significantly decreased and shortened viral excretion in nasal swabs and an improved protection to the viral challenge. In contrast, the co-administration of porcine IL-2 or IFN-γ had no adjuvant effects. Our results thus demonstrate for the first time that the application of porcine GM-CSF gene in a DNA vaccine formulation can exert immuno-adjuvant and protective effects with single vaccination in the natural host pig against Aujeszky’s disease.  相似文献   

12.
Surra, caused by Trypanosoma evansi, is an economically important veterinary disease of the tropics. Lack of effective drugs or vaccines have made surra a severe economic burden particularly in Asia and sub-Saharan Africa. In this study, a naked DNA construct encoding full length T. evansi beta (β) tubulin gene was used to immunize mice, to elicit a T. evansi β tubulin protein specific humoral immune response, delineated by ELISA. The serum cytokine profile post immunization, as determined by flow cytometry bead based assay, showed a predominant T helper cell Type 1 (Th1) response with significant increase in levels of IFNγ and TNFα. Lethal challenge with T. evansi blood-form trypomastigotes post immunization generated a β tubulin specific recall response and a stronger Th1 type serum cytokine profile which correlated with an extended survival and better control of parasitemia in the immunized mice.  相似文献   

13.
试验旨在构建表达猪附红细胞体ENO基因的质粒DNA,并测定其免疫效果。将猪附红细胞体ENO基因克隆到PVAX1真核表达载体上,然后转染到Vero细胞中进行表达并测定其免疫效果。将18只BALB/c小鼠（雌雄各半）随机分为3组（PVAX1-ENO质粒DNA免疫组、PVAX1空载体对照组及PBS对照组）,每组6只,每组小鼠对应免疫接种PVAX1-ENO质粒DNA、PVAX1空质粒和PBS。分离血清并通过ELISA方法测定血清中ENO蛋白抗体效价、IgG1和IgG2a抗体水平及IFN-γ和IL-4细胞因子水平。三免2周后每组选取3只小鼠检测CD4+和CD8+含量。结果显示,本试验成功构建了PVAX1-ENO质粒DNA,经PCR和酶切鉴定正确,并能在Vero细胞中成功表达。PVAX1-ENO质粒DNA免疫组ENO蛋白抗体水平、IgG1和IgG2a抗体水平、IFN-γ和IL-4细胞因子水平及CD4+和CD8+含量均显著高于PVAX1空载体对照组及PBS对照组（P<0.05）。结果表明,PVAX1-ENO质粒DNA可显著提高BALB/c小鼠的体液免疫水平,并在一定程度上刺激BALB/c小鼠细胞免疫。  相似文献   

14.
旨在开发防治热带螨过敏症的兽用核酸疫苗,本试验通过对热带无爪螨主要变应原Blo t 5和Blo t 21的基因序列进行密码子优化,构建了热带螨主要变应原融合基因的真核表达载体pVAX1-PADRE-Blo t 5-21-CpG。为验证该真核表达载体的免疫效果,采用皮下注射,以100 μg/100 μL量的pVAX1-PADRE-Blo t 5-21-CpG核酸免疫BALB/c小鼠(n=6),通过ELISA检测小鼠血清中特异性IgG、IgG1和IgG2a的水平变化;流式细胞术检测小鼠脾淋巴细胞中调节性T细胞的变化。结果显示,真核表达质粒pVAX1-PADRE-Blo t 5-21-CpG免疫小鼠后可诱导特异性IgG和IgG2a水平升高,且IgG2a/IgG1的比值升高,这暗示免疫后小鼠机体发生偏向Th1型的免疫反应。此外,该核酸疫苗可诱导小鼠产生较高水平的CD4+CD25+Foxp3+ T细胞,这表明该真核表达质粒免疫小鼠后可能会诱发免疫抑制。  相似文献   

15.
Interleukin 2 (IL-2) is a T cell proliferation factor released by Th0- and Th1-type helper T cells and is an essential cytokine for immune responses. In the present study, recombinant glutathione S-transferase (GST)-guinea pig IL-2 (GPIL-2) fusion protein was prepared by Escherichia coli (E. coli) and by using this protein as an immunogen, monoclonal antibodies (mAbs) against GPIL-2 were produced to establish a basis for a research on immune responses in guinea pigs. Three stable hybridoma cell lines were established, and specific binding of each mAb to recombinant GPIL-2 produced by E. coli and insect cells infected with recombinant baculovirus was shown by enzyme linked immunosorbent assay (ELISA) and/or immunoblot analysis. Isotype analyses of these mAbs revealed that all three mAbs were IgG1 and had kappa chain. Furthermore, assessment of their epitopes by competition binding assay indicated that the mAbs obtained in this study bound to three different epitopes. Thus, a sandwich ELISA based on the two mAbs specific to different GPIL-2 epitopes was developed for detection of GPIL-2, which had a sensitivity threshold of about 0.3 ng/ml of GPIL-2.  相似文献   

16.
Equine recurrent airway obstruction (RAO) is thought to result from an aberrant immune response to inhaled antigens, modulated by T lymphocytes via the secretion of pro-inflammatory cytokines. However data relating to the phenotypes of the T lymphocytes present in peripheral blood and bronchoalveolar lavage fluid of RAO horses and their cytokine profiles are contradictory. The aim of this study was to further investigate the cytokine (IL-4, IL-5, IL-13 and INF-gamma) mRNA expression profile in peripheral blood lymphocytes and bronchoalveolar lavage lymphocytes from RAO and control horses, before and at 48 h after horses were exposed to hay/straw. In contrast to previous studies, cytokine expression was quantified in populations of CD4 and CD8 T lymphocytes which were purified using magnetic bead antibody cell separation. Hay/straw exposure induced clinical airway obstruction, airway neutrophilia and airway lymphocytosis in RAO horses, and, induced a mild, but significant, airway neutrophilia in controls. However, hay/straw exposure had no significant effect on peripheral blood lymphocyte or bronchoalveolar lavage lymphocyte cytokine expression in either group. In conclusion, RAO was not associated with alterations in lymphocyte cytokine expression that are consistent with Th1 or Th2 responses, but rather with a general down-regulation in expression of the measured cytokines in peripheral blood lymphocytes and bronchoalveolar lavage lymphocytes.  相似文献   

17.
为评估SjTSP2分子作为日本血吸虫DNA疫苗候选抗原分子的潜力,本实验扩增了编码该分子的DNA片段,构建了重组真核质粒pVAX1/SjTSP2,检测其在哺乳动物细胞中表达情况后,通过基因枪轰击法免疫小鼠,应用ELISA、流式细胞术等检测重组质粒诱导的免疫反应,计算减虫减卵率,评估对小鼠日本血吸虫病的免疫保护效果。间接免疫荧光试验结果显示该质粒能在293T细胞中表达。质粒免疫小鼠诱导了显著升高的特异性IgG抗体和IFN-γ、IL-4等细胞因子。小鼠免疫保护试验结果表明,免疫组小鼠虫荷数较PBS对照组增加12.4%(P=0.368),但肝组织虫卵减少10.01%(P=0.486)。说明制备的DNA疫苗能刺激小鼠产生较强的免疫反应,但诱导的免疫保护作用并不理想,为血吸虫DNA疫苗研究提供了参考数据。  相似文献   

18.
Normal C3H/HeN female mice were used to develop an animal model of Taenia saginata asiatica oncosphere infection. The host cellular immune response in this model was analyzed by a cytokine enzyme-linked immunosorbent assay (cytokine ELISA) and flow cytometry. Tumor-like cysts containing cysticerci were recovered from the inoculation sites of female mice 7 weeks postinfection with the T. saginata asiatica oncospheres. A sharp increase and sustained elevation in the ability of spleen cells to produce interferon-γ and interleukin (IL)-2 revealed that cellular immunity played an important role during the infection. An immediate increase in the levels of IL-6 at 1 week postinfection indicated the induction of a local acute inflammatory response. However, no significant change in the levels of IL-10 indicated that Th2 cells were not involved in this immune response. The patterns of cell distribution revealed by flow cytometry also supported the same finding. These results suggested that Th1 cells played a major role in the immune response in C3H/HeN mice during the early stages of the oncosphere infection and that the Th2 response was not induced during the stage of cysticercus formation.  相似文献   

19.
Bovine respiratory syncytial virus (BRSV) is a respiratory pathogen of cattle that causes severe disease in calves alone and as one of several viruses and bacteria that cause bovine respiratory disease complex. Like human RSV this virus modulates the immune response to avoid stimulation of a vibrant CD8+ T cytotoxic cell response and instead promotes a Th2 response. The Th2 skew sometimes results in the production of IgE antibodies and depresses production of the Th1 cytokine interferon γ. Innate immune cells have a pivotal role in guiding the adaptive response to BRSV, with selective secretion of cytokines by pulmonary dendritic cells. Here we review some of the pertinent observations on immune responses to BRSV infection and vaccination and illustrate how experimental infection models have been used to elucidate the immunopathogenesis of BRSV infection. Recent experiments using intranasal vaccination and/or immune modulation with DNA based adjuvants show promise for effective vaccination by the stimulation of Th1 T cell responses.  相似文献   

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