日本血吸虫复合表位DNA疫苗免疫保护作用的研究

目的研究日本血吸虫复合表位DNA疫苗诱导BALB/c小鼠抗血吸虫感染的免疫保护作用。方法将40只雌性BALB/c小鼠随机分为4组:pcDNA3.1组(对照组),每鼠经两侧股四头肌注射100μg pcDNA3.1质粒DNA,每侧50μg;TPI组,每鼠肌注100μg pcDNA3.1-TPI质粒DNA;TP组,每鼠肌注100μg pcDNA3.1-T-linker-P质粒DNA;PT组,每鼠肌注100μg pcDNA3.1-P-linker-T质粒DNA。每隔2周加强免疫1次,剂量和方法相同,共免疫3次。末次免疫后4周每鼠经腹部皮肤攻击感染(45±1)条日本血吸虫尾蚴,45d后剖杀,计数成虫及肝脏虫卵数。首次免疫前2 d及感染前2 d尾静脉采血,间接ELISA检测特异IgG及IgG1I、gG2a水平。末次免疫后3周,每组取2只小鼠制备脾细胞,双抗体夹心法检测脾细胞经ConA和rSjCTPI刺激后培养上清中的IL-2I、L-4和IFN-γ水平。结果TP组和PT组小鼠减虫率分别为34.76%和36.14%,显著高于TPI组(P<0.05)和对照组(P<0.01);减卵率分别为51.20%和50.79%,与TPI及对照组比较差异有显著性(P<0.05)。TP组和PT组小鼠血清特异性IgG水平均升高(P<0.05),IgG2a/IgG1的比值分别为4.23和4.34。脾细胞经ConA和rSjCTPI刺激后,IL-2水平TP组和PT组较对照组均升高。结论复合表位DNA疫苗能诱导小鼠产生抗血吸虫感染的免疫保护力,效果优于rSjCTPI疫苗。     

日本血吸虫多价DNA疫苗免疫保护作用的研究

目的研究日本血吸虫多价DNA疫苗诱导BALB/c小鼠的免疫保护作用.方法65只BALB/c雌性小鼠随机分为5组,各组小鼠分别肌肉注射纯化的质粒DNA pcDNA3.1(对照组)、pcDNA3.1-TPI(TPI)、pcDNA3.1-(CDR3)6[(CDR3)6]、pcDNA3.1-TPI-linker-(CDR3)6(TLC)和pcDNA3.1-(CDR3)6-linker-TPI(CLT),每鼠100μg.每隔2周加强免疫1次,共3次.末次免疫后4周每鼠经腹部皮肤攻击感染(45±1)条日本血吸虫尾蚴,45 d后剖杀,计数成虫及肝脏虫卵数.首次免疫前2天及感染前2天经尾静脉采血检测IgG抗体水平、抗体亚类IgG1、IgG2a.末次免疫后2周取小鼠脾脏制备单个脾细胞,检测细胞因子IL-2、IL-4、IFN-γ的水平.结果TPI、TLC组和CLT组小鼠血清都检测到特异性IgG抗体,抗体亚类IgG2a/IgG1的比值分别为1.71、2.71和4.70,而其他两组则未检测到特异性IgG抗体;TPI、TLC组和CLT组小鼠的IL-2、IFN-γ较对照组均有不同程度的升高,IL-4则无明显差异.多价DNA疫苗TLC组和CLT组减虫率分别达到37.30%、39.09%,减卵率分别为41.61%、49.54%,均显著高于TPI组和(CDR3)6组(P均＜0.05).结论多价DNA疫苗相对于单价DNA疫苗能诱导小鼠产生较高的免疫保护作用,且诱导宿主产生较高的以Th1为主的免疫应答.     

CpG免疫刺激序列增强日本血吸虫TPIDNA疫苗免疫保护作用的研究

目的研究CpG免疫刺激序列对日本血吸虫中国大陆株磷酸丙糖异构酶DNA疫苗诱导BALB/c小鼠免疫保护的增强作用.方法设计合成一对含6个免疫刺激序列的寡脱氧核苷酸,克隆到真核表达载体pcDNA3.1第5314碱基Ssp I酶切位点,改建为pcDNA3.1-CpG.再将SjCTPIDNA片段克隆到pcDNA3.1-CpG的多克隆位点区,构建为pcDNA3.1-TPI/CpG.56只BALB/c雌性小鼠随机分为4组,各组小鼠分别肌肉注射pcDNA3.1、pcDNA3.1-TPI、pcDNA3.1-CpG、pcD-NA3.1-CpG/TPI质粒DNA,每鼠100 μg.每隔2周加强免疫1次,共3次.末次免疫后4周每鼠经腹部皮肤攻击感染(45士1)条日本血吸虫尾蚴,45 d后剖杀,计数成虫及肝脏虫卵数.首次免疫前2d及攻击感染前2 d经尾静脉采血检测抗体水平、抗体亚类IgG1、IgG2a.末次免疫后2周制备脾细胞,检测细胞因子IL-2、IL-4、IFN-γ的水平.结果 pcDNA3.1-TPI组和pcDNA3.1-TPI/CpG组小鼠血清都检测到特异性IgG抗体,抗体亚类IgG2./IgG1的比值分别为1.76和2.67,而其他两组则未检测到特异性IgG抗体;pcDNA3.1-TPI组和pcDNA3.1-TPI/CpG组小鼠的IL-2、IFN-γ较对照组均有不同程度的升高,IL-4无明显差异;pcDNA3.1-TPI组和pcDNA3.1-TPI/CpG组分别获得了25.98%和34.54%的减虫率,后者高于前者,并分别获得了27.68%和29.50%的减卵率.结论 CpG免疫刺激序列似能增强DNA疫苗在小鼠体内诱导的Th1型免疫应答,并提高DNA疫苗的免疫保护作用.     

日本血吸虫P14基因纳米微球-DNA疫苗的免疫保护作用

目的 探讨日本血吸虫碱性调宁蛋白样蛋白P14基因的重组真核表达载体(pcDNA3.1(+)-SjP14)对小鼠血吸虫感染的免疫保护作用.方法 制备无内毒素pcDNA3.1 (+)-SjP14及纳米微球DNA疫苗,将雌性BALB/c小鼠随机分为3组,每组10只,分别为生理盐水对照组、pcDNA3.1(+)-Sj P14组及纳米微球-DNA疫苗组.各组小鼠分别肌肉注射生理盐水和pcDNA3.1(+)-Sj P14、纳米微球DNA疫苗100μg/鼠·次,每2周免疫一次,共3次.末次免疫后2周,尾蚴攻击,6w后处死小鼠,收集成虫,计算减虫率;同时留取肝脏,部分消化后在显微镜下行虫卵计数,计算减卵率.结果 pcDNA3.1(+)-Sj P14p核酸疫苗能明显提高小鼠的抗血吸虫感染能力,减虫率和减卵率分别达到44.6％和61.6％;纳米微球-DNA疫苗免疫能进一步提高小鼠抗血吸虫感染作用,减虫率和减卵率分别提高至56.2％和73.5％.结论 pcDNA3.1(+)-Sj P14核酸疫苗有一定程度的抗血吸虫感染作用,pcDNA3.1(+)-SjP14-纳米微球复合物疫苗免疫能增强小鼠对血吸虫感染的免疫保护作用.     

SjESG-2A锤头状核酶表达载体构建及其抗日本血吸虫虫卵发育研究

目的设计并合成日本血吸虫中国大陆株卵壳蛋白基因2A(eggshell protein gene 2A,ESG-2A)的特异性锤头状核酶并构建真核表达载体。探讨其在BALB/c小鼠体内的抗日本血吸虫虫卵发育作用。方法运用计算机软件人工设计并合成核酶基因(RZ),将核酶基因克隆到真核表达载体pcDNA3.1(+)中,采用双酶切、琼脂糖凝胶电泳及DNA序列测定方法鉴定阳性克隆。以日本血吸虫尾蚴感染BALB/c小鼠,建立动物模型。大量抽提阳性重组子,分别在小鼠感染时、感染后2w、感染后4w,将其经后腿胫前肌免疫BALB/c小鼠,共3次。小鼠感染6w后计数成虫负荷及肝组织虫卵数。ELISA法检测小鼠脾淋巴细胞培养上清IFN-γ和IL-4的水平。结果经酶切电泳及DNA测序证实合成的核酶基因序列正确并已被准确克隆入pcDNA3.1(+)的XbaI和EcoR I酶切位点之间,命名为pcRz-ESG-2A。在核酶组,IFN-γ的水平呈上升趋势,IL-4的水平呈先上升后下降;在空载体组和生理盐水组,IFN-γ的水平呈上升趋势,IL-4的水平也呈上升趋势。核酶组免疫BALB/c小鼠能诱生减虫率25.64%和减卵率44.21%。结论成功合成SjESG-2A特异性的锤头状核酶基因并构建了该基因的真核表达载体。核酶在已感染日本血吸虫尾蚴的BALB/c小鼠体内具有抗日本血吸虫虫卵发育的作用。     

幽门螺杆菌ureI核酸疫苗免疫活性的初步研究

目的 观察幽门螺杆菌ureI核酸疫苗诱导C57BL/6小鼠产生体液免疫应答及细胞免疫应答水平.方法 重组质粒pcDNA3.1(+)/ureI、空质粒pcDNA3.1(+)及PBS分别肌注免疫C57BL/6小鼠.ELISA法检测小鼠血清中特异性IgG抗体水平以及脾淋巴细胞培养上清中IL-4和IFN-γ含量,MTT比色法检测脾淋巴细胞增殖反应,PCR和免疫荧光组化法检测ureI基因和蛋白表达.结果 pcDNA3.1(+)/ureI能够诱导小鼠产生特异性IgG抗体,该组小鼠脾淋巴细胞经UreI重组蛋白刺激后,其刺激指数和培养上清中IL-4、IFN-γ含量明显升高; ureI基因可在小鼠肌细胞中有效表达.结论 pcDNA3.1(+)/ureI核酸疫苗能刺激C57BL/6小鼠产生较强的体液免疫应答和细胞免疫应答,为进一步研究该疫苗的免疫保护作用奠定了基础.     

弓形虫SAG1-SAG2复合DNA疫苗免疫小鼠诱导的免疫保护性

目的利用已构建的弓形虫主要表面抗原SAG1DNA疫苗及SAG1-SAG2复合DNA疫苗,接种BALB/c小鼠,观察疫苗的免疫保护性。方法将两核酸疫苗分别通过肌肉注射免疫小鼠,对照组注射pcDNA3.1空质粒。ELISA法检测血清IgG抗体及细胞因子IL-2、IFN-γ和IL-4;用四甲基偶氮唑盐(MTT)法测定免疫鼠脾脏NK细胞杀伤率;流式细胞仪测定T细胞亚群;用弓形虫速殖子腹腔攻击感染小鼠,观察小鼠的生存时间。结果SAG1-SAG2组小鼠IgG抗体、IFN-γ、IL-2及CD4 /CD8 细胞比例均高于SAG1组(P<0.05);各组均未检测到IL-4;复合DNA疫苗组感染弓形虫后生存时间较单基因组延长(P<0.01)。结论弓形虫SAG1-SAG2复合DNA疫苗较SAG1单基因疫苗具有更好的免疫保护性。     

日本血吸虫TPI DNA疫苗基因密码子优化增强免疫保护作用的研究

目的　 研究日本血吸虫中国大陆株磷酸丙糖异构酶基因（TPI基因）密码子优化后的DNA疫苗增强免疫保护作用的效果。 方法　 60只BALB/c雌性小鼠随机均分为A（pcDNA3.1空质粒对照组）、B（pcDNA3.1-TPI组）、C （pcDNA3.1-TPI-mHSP70组）、D（pcDNA3.1-TPI.opt组）、E（pcDNA3.1-TPI.opt-mHSP70组）等5组。每鼠肌肉注射相应的纯化质粒DNA 100 μg,每隔3周免疫1次,共3次。末次免疫后4周,每鼠经腹部皮肤攻击感染日本血吸虫尾蚴（40±1）条,42 d后剖杀,计数成虫及肝脏虫卵数。首次免疫前2 d及感染前2 d经尾静脉采血,检测IgG及IgG₁、IgG_2a的水平。攻击感染前2 d取脾脏,制备单个脾细胞,用流式细胞仪检测白细胞介素2（IL-2）、IL-4、IL-5、γ干扰素（IFN-γ）及肿瘤坏死因子（TNF）的水平。 结果　 B、C、D、E组小鼠血清均检测到特异性IgG及IgG_2a与IgG₁抗体,IgG_2a/IgG₁的比值分别为1.73、2.06、2.44、3.09。D、E组的IL-2、IFN-γ、TNF含量较B、C组均有不同程度地升高。D、E组减虫率分别为36.03%、39.03%,减卵率分别为41.71%、46.85%,均显著高于B、C组（P<0.01）。 结论 TPI基因密码子优化后的DNA疫苗相对于未优化TPI DNA疫苗能诱导小鼠产生较高的免疫保护作用,且诱导宿主产生较强的,及以Th1为主的免疫应答。     

免疫刺激序列增强日本血吸虫DNA疫苗的免疫保护作用

目的　探讨免疫刺激序列在日本血吸虫Mr 23 000膜蛋白 (SjC23)DNA疫苗诱导BALB/c小鼠抗血吸虫感染中的作用。　方法　将SjC23基因片段克隆到增加了免疫刺激序列的真核表达质粒 pcDNA3.1-CpG中,构建pcDNA3.1-SjC23/CpG。 40只雌性BALB/c小鼠随机分为 4组 ,① pcDNA3.1对照组 ;②pcDNA3.1-SjC23组 ;③ pcDNA3.1-CpG组 ;④ pcDNA3.1-SjC23/CpG组。每鼠经两侧股四头肌注射质粒DNA共100 μg ,隔 2周加强免疫 1次 ,共 3次。末次免疫后 4周经腹部皮肤感染日本血吸虫尾蚴 45条 /鼠 ,45d后计数成虫及肝脏虫卵数。首次免疫前和感染前 2d分别经尾静脉采血 ,检测IgG及IgG1、IgG2a。末次免疫后 3周取小鼠脾细胞 ,检测经伴刀豆球蛋白和SjC23重组蛋白刺激后小鼠白细胞介素 2 (IL-2 )、白细胞介素 4(IL-4)和γ干扰素 (IFN-γ)。用51Cr释放法检测经SjC23重组蛋白刺激后脾细胞对小鼠淋巴瘤细胞的杀伤作用。　结果　②组和④组减虫率分别为 2 8.1%和 3 5.1% ,减卵率分别为 2 1.6%和 2 6.5 %。④组减虫率显著高于②组 (P <0.0 5 )。这两组均检测到特异性IgG ,IgG2a/IgG1比值分别为 10.1和 12.2。脾细胞经伴刀豆球蛋白和SjC23重组蛋白刺激后的IL-2水平 ,②组较①组、④组较③组均有升高。②组脾细胞对靶细胞的杀伤活性为9.7%, ④组为40.0%。 结论 疫苗载体中增加免疫刺激序列，可提高SjC23 DNA 疫苗在BALB/c小鼠中诱导产生的免疫保护作用。     

日本血吸虫调宁蛋白样蛋白P14基因DNA疫苗对小鼠免疫保护作用研究

摘 要：目的 研究日本血吸虫调宁蛋白样蛋白P14基因DNA疫苗对小鼠免疫保护作用。 方法 制备无内毒素DNA疫苗,用于免疫小鼠。将雌性BALB/c小鼠随机分为4组,每组10只。生理盐水组给予100 μl/鼠/次;空质粒组100 μg/鼠/次、pcDNA3.1(+)-SjP14组、pcDNA3.1(+)-SjP14 + pcDNA3.1(+)-SjGST组分别经肌肉给予100 μg/鼠/次;同上每2周免疫一次,共3次。末次免疫后2周,经腹部皮肤感染日本血吸虫尾蚴（30±1）条/鼠。尾蚴攻击6周后解剖小鼠,收集成虫和血清,计算减虫率并检测血清IgG1、IgG2a及总IgG;同时留取肝脏,部分消化后在显微镜下行虫卵计数,计算减卵率,部分肝脏用于组织病理学分析（HE染色法）,观察肝细胞变化及肉芽肿情况。结果 与NS对照组比较,pcDNA3.1(+)-Sj P14p核酸疫苗组减虫率和减卵率分别达到45.1%（P<0.05）和62.0%（P<0.001）;SjP14核酸疫苗与SjGST核酸疫苗联合免疫组减虫率和减卵率分别提高至56.3%（P<0.01）和73.9%（P<0.001）;SjGST和SjP14 组减虫率大于SjP14疫苗组,但两组之间差异无显著性（P＞0.05）; SjGST和SjP14组减卵率明显大于SjP14疫苗组, 两组之间差异有显著性（P<0.001）。SjGST和SjP14组与SjP14组血清IgG1、IgG2a及总IgG水平在免疫6周、12周后均较对照组显著提高（P<0.01）,但SjGST和SjP14组与SjP14之间差异无显著性（P＞0.05）。肝组织切片镜下显示,pcDNA3.1(+)-SjP14组肝脏病变较生理盐水组和空质粒组明显减轻,pcDNA3.1(+)-SjP14 + pcDNA3.1(+)-SjGST组肝脏损伤程度最轻,虫卵肉芽肿周围炎症反应轻,肉芽肿面积较小。结论 pcDNA3.1(+)-Sj P14核酸疫苗有一定程度的抗血吸虫感染作用,pcDNA3.1(+)-SjP14与pcDNA3.1(+)-SjGST疫苗联合免疫能增强小鼠对血吸虫感染的保护。     

含弓形虫ROP1基因真核表达重组质粒DNA免疫小鼠的研究 IV.免疫鼠血清细胞因子IFN-γ、IL-2及NO的测定

目的　用 pc- ROP1重组质粒免疫小鼠 ,观察其对细胞因子 IFN-γ、IL - 2及 NO的影响。方法　碱裂解法大量制备 pc- ROP1质粒 DNA,经肌肉注射免疫 BAL B/ c小鼠 ,每只鼠注射 10 0μg,两周后同量加强免疫一次 ,以 pc DNA 3空质粒及生理盐水组为对照。分别于免疫后第 30天、5 0天、70天共三次用双夹心 EL ISA测定血清细胞因子 IFN-γ、IL - 2含量 ;酶法测定NO活性。结果　三次检测免疫组 IFN-γ、IL - 2及 NO含量均显著高于对照组 ,随着免疫时间的延长有增高趋势。结论　 pc-ROP1重组质粒 DNA免疫小鼠 ,可刺激细胞因子 IFN-γ、IL - 2产生 ,NO分子的释放     

The protective immunity of a DNA vaccine encoding Schistosoma japonicum Chinese strain triose-phosphate isomerase in infected BALB/C mice

The development of a DNA vaccine for schistosomiasis japonica and testing the protective efficacy after challenge in BALB/c mice were performed. Thirty-nine female BALB/c mice were divided into three groups. Each mouse of the control group was injected intramuscularly with 100 microg of pcDNA3.1 DNA. In the TPI group, each mouse was injected with 100 microg of pcDNA3.1-SjCTPI DNA. The TPI+IL-12 group was injected with 100 microg of pcDNA3.1-SjCTPI DNA and 100 microg of the mixture of pcDNA3.1-P35 and pcDNA3.1-P40 DNA. Each mouse was immunized three times at two-week intervals and challenged with 45 cercariae of Schistosoma japonicum Chinese strain four weeks post-immunization. Then the mice were sacrificed and perfused at 45 days after challenge; the recovered worms and hepatic eggs were counted. Cytotoxic T lymphocyte (CTL) activity mediated by SjCTPI was detected with the 51Cr release assay. ELISA was performed for the detection of anti-rTPI antibodies. Anti-rTPI antibody detection with ELISA after immunization showed ten serum samples from the control group were negative, five of ten serum samples from the TPI group were weakly positive, six of ten from the TPI+IL-12 group were also weakly positive. The CTL activity of the control group was 9.1%, while CTL activities of the TPI group and the TPI+IL-12 group were 27.6% and 54.4%, respectively. The worm and egg reduction rates of TPI group and the TPI+IL-12 group were 30.2%, 52.9%, 32.7%, and 47.0%, respectively in comparison with the control group. This study further proved the possibility of the SjCTPI DNA vaccine as a potential DNA vaccine for schistosomiasis.     

The protective immunity produced in infected C57BL/6 mice of a DNA vaccine encoding Schistosoma japonicum Chinese strain triose-phosphate isomerase

The development of a SjCTPI DNA vaccine for Schistosoma japonicum and the detection of the immune responses to and the protective efficacy of immunization were performed and challenged in C57BL/6 mice. According to the gene sequence of SjCTPI and murine IL-12, three pairs of primers were designed. The full length cDNA encoding SjCTPI and P35, P40 amplified from pUC19-SjCTPI and murine IL-12 by PCR were subcloned into an eukaryotic expression vector (pcDNA3.1). Forty-five female C57BL/6 mice were divided into three groups; each mouse of the control group was injected with 100 pg of pcDNA3.1 by i.m. route; the TPI group was injected with 100 microg of pcDNA3. 1-SjCTPI; the TPI+IL- 12 group was injected with 100 microg of pcDNA3.1-SjCTPI and 100 pg of mixture of pcDNA3.1-P35 and pcDNA3.1-P40. Each mouse was immunized at weeks 1 and 5 and challenged with 45 cercariae of Schistosoma japonicum Chinese strain at week 9. The mice were killed and perfused 45 days after challenge; the numbers of recovered worms and hepatic eggs were counted. The expression of SjCTPI in muscle tissue was determined by an immunohistochemical method. Culture of spleen cells showed the production of IL-2, IL-4, IL-10 and IFN-gamma with the stimulation of specific antigen before and after challenge. Sera were collected from each group before immunization, before challenge and two weeks post challenge; ELISA and Western-blot tests were performed for detection of anti-rTPI antibodies. The antigen of SjCTPI was expressed in the membrane and plasma of the muscle cells of C57BL/6 mice. The obvious rising of IL-2 in TPI group and TPI+IL-12 group before and after challenge was seen. The anti-rTPI antibody detection with Western-blot showed that ten serum samples from the control group were negative; nine of ten serum samples from the TPI group were weakly positive, eight of ten from the TPI+IL-12 group were weakly positive. The worm and egg reduction rates of TPI group and TPI+IL- 12 group were 27.9% and 13.7%, 31.9% and 18.6% respectively in comparison with the pcDNA group. pcDNA3.1-TPI DNA vaccine could confer partial protection against a subsequent challenge of Schistosoma japonicum in C57BL/6 mice and might therefore be a potential DNA vaccine.     

肺炎嗜衣原体MOMP和人IL-2融合基因DNA疫苗的免疫原性研究

目的构建肺炎嗜衣原体(Chlamydophila pneumoniae,Cpn)主要外膜蛋白(MOMP)单基因及momp和人IL-2融合基因的真核表达载体并比较其免疫反应性,为研制Cpn核酸疫苗提供理论和实验依据。方法扩增Cpn momp及人IL-2基因并将二者融合,将momp和momp-IL-2分别克隆至pcDNA3.1(+)真核表达载体;制备纳米粒DNA疫苗免疫BALB/c小鼠,免疫荧光组化法检测重组质粒在小鼠组织内的稳定表达;ELISA法检测小鼠血清中的特异性抗体和小鼠脾细胞培养上清中IFN-γ水平;MTT法测定脾淋巴细胞特异性增殖反应。结果成功制备了pcDNA3.1(+)-momp和pcD-NA3.1(+)-momp-IL-2的纳米核酸疫苗;Cpn momp单基因和momp-IL-2融合基因核酸疫苗均能刺激小鼠产生特异性抗体,且pcDNA3.1(+)-momp-IL-2能诱导小鼠产生更高效价的特异性抗体(P<0.05);pcDNA3.1(+)-momp-IL-2诱导小鼠脾细胞产生IFN-γ的量及对特异抗原的刺激指数明显高于pcDNA3.1(+)-momp。结论Cpn momp单基因核酸疫苗和momp-IL-2融合基因核酸疫苗均能刺激小鼠产生较强的体液免疫和细胞免疫应答;pcDNA3.1(+)-momp-IL-2的免疫效果强于pcDNA3.1(+)-momp。     

日本血吸虫中国株琥珀酸脱氢酶铁硫蛋白真核重组体的构建及其免疫小鼠的保护性研究

目的研究日本血吸虫琥珀酸脱氢酶铁硫蛋白(SjSDISP)全长编码基因DNA疫苗诱导小鼠的免疫保护性效果。方法将全长SjSDISP基因克隆到真核表达载体pcDNA3上,构建真核表达质粒pcDNA3-SjSDISP,用重组裸DNA免疫昆明小鼠3次,间隙2W,末次免疫后第二周进行日本血吸虫尾蚴攻击感染,感染后42 d处死小鼠,剖杀冲虫,计算减虫率和减卵率。结果经双酶切、PCR和测序验证,表明真核表达质粒pcDNA3-SjSDISP构建成功。动物免疫保护性实验结果显示:pcDNA3-SjSDISP疫苗组减虫率较低,与对照组相比减虫效果不明显(P>0.05);但在每克肝卵、每克粪卵和每雌子宫内卵方面,与对照组相比差异均具有显著性(P<0.01)。结论日本血吸虫琥珀酸脱氢酶铁硫蛋白DNA疫苗可能主要在抗血吸虫卵胚发育或抗生殖起作用,具有潜在的疫苗研究与开发价值。     

弓形虫SAG1单基因疫苗与SAG1-ROP2复合基因疫苗的免疫效果观察

目的构建弓形虫主要表面抗原SAG1单价基因疫苗及其与棒状体蛋白ROP2的复合基因疫苗,接种BALB/c小鼠,观察疫苗的免疫保护性。方法构建重组质粒pcDNA3.1SAG1及pcDNA3.1SAG1ROP2。将两核酸疫苗分别免疫小鼠,ELISA法检测血清IgG抗体、IFNγ、IL4;流式细胞仪测定T细胞亚群;弓形虫速殖子腹腔攻击感染观察小鼠生存时间。结果获得pcDNA3.1SAG1、pcDNA3.1SAG1ROP2重组质粒;pcDNA3.1SAG1ROP2组小鼠IgG抗体(P<0.05)、IFNγ(P<0.01)及CD8+细胞比例(P<0.05)均高于pcDNA3.1SAG1组;实验组组均未测到IL4;复合基因组感染弓形虫后生存时间较单基因组延长(P<0.01)。结论弓形虫不同生活阶段的抗原基因复合疫苗较单基因疫苗具有更好的免疫保护性。     

日本血吸虫中国大陆株23 kDa膜蛋白DNA疫苗诱导小鼠保护性免疫的研究

目的　研究日本血吸虫中国大陆株 2 3kDa膜蛋白 (SjC2 3)DNA疫苗诱导C5 7BL/6小鼠免疫保护作用。方法　将全长的SjC2 3基因克隆到真核表达载体pcDNA3.1,构建DNA疫苗 pcDNA3.1 SjC2 3。制备SjC2 3及IL 12的两个亚单位 p35、p4 0的DNA疫苗和对照 pcDNA3.1。 4 8只C5 7BL/6小鼠随机分为A、B、C 3组。A组小鼠肌注 10 0 μgpcDNA3.1;B组注射 10 0 μg pcDNA3.1 SjC2 3;C组肌注 pcDNA3.1 SjC2 3、pcDNA3.1 p35及pcDNA3.1 p4 0各 10 0 μg的混合物。每隔 2周各免疫 1次 ,共 3次。第 8周每鼠感染 4 5± 2条 /只尾蚴 ,4 5d后剖杀 ,计数成虫及肝内虫卵。采用免疫组化法检测SjC2 3及 p35、p4 0在小鼠局部组织内的表达 ;用脾细胞培养法检测经rSjC2 3 HD刺激后 ,攻击前、后小鼠脾细胞IL 2、IL 4、IL 10和IFN γ的水平。用Westernblotting检测血清中抗SjC2 3抗体。结果　SjC2 3以及p35、p4 0在免疫小鼠股四头肌细胞膜和细胞浆均获得表达。IL 2和IFN γ的水平攻击前、后在B组和C组均明显升高。Westernblotting检测抗SjC2 3抗体结果表明 ,免疫后两周 ,B组 8/10份血清为阳性 ,C组 9/10份血清阳性。B组和C组分别获得 2 6 .9%和 35 .4 %的减虫率 ,C组显著高于B组 (P <0 .0 5 ) ;减卵率分别为 2 2 .2 %和 2 8.4 %。结论　SjC     

CEA Plasmid as Therapeutic DNA Vaccination against Colorectal Cancer

Background: Human colorectal cancer cells overexpress carcinoembryonic antigen (CEA). CEA is a glycoprotein which has shown to be a promising vaccine target for immunotherapy against colorectal cancer. Objective: To design a DNA vaccine harboring CEA antigen and evaluate its effect on inducing immunity against colorectal cancer cells in tumor bearing mice. Methods: In the first step the coding sequence of the CEA was cloned into the pcDNA3.1 vector. The mice were injected with the vaccine construct and the immune responses were monitored during the experiment period. The specific IgG anti-CEA, IFN-γ, IL-2 and IL-4 were measured by ELISA and levels of IFN-γ was detected by ELISpot assay. The lymphocyte proliferation was assessed using a 5-bromo-2-deoxyuridine (BrdU) cell proliferation assay kit. Results: Immunization of the mice with the CEA plasmid resulted in stimulation of CEA-specific T cell and antibody responses. The serum level of specific IgG antibodies against CEA was increased in immunized mice. Moreover, the injection of CEA plasmid led to the stimulation of T-helper-1 by increase in the secretion of IFN-γ, IL-2 and lymphocyte proliferation response. Conclusion: As the CEA DNA vaccine displayed encouraging antitumor effects, therefore, we suggest that it can be a potential therapeutic modality for colorectal cancer and is worthy of further investigation.