Protective efficacy of hepatitis E virus DNA vaccine administered by gene gun in the cynomolgus macaque model of infection

The protective efficacy of a DNA vaccine against hepatitis E virus (HEV) infection was tested in cynomolgus macaques (cynos) vaccinated with a plasmid containing a full-length HEV open-reading frame 2 (ORF2) sequence (Burmese strain) and subsequently challenged with a heterologous strain of HEV (Mexican strain). Cynos administered vaccine by gene gun developed antibodies to HEV (anti-HEV), whereas cynos administered vaccine by intradermal injections and cynos administered a mock DNA construct did not develop anti-HEV. Anti-HEV-positive cynos were protected from HEV infection after challenge with an inoculum that produced infection in the anti-HEV-negative cynos. These results indicate that DNA vaccine with HEV ORF2 administered by gene gun is protective against a heterologous viral challenge.     

猪囊尾蚴病重组DNA疫苗pcDNA 3.1-TSO45W在小鼠体内诱导的体液免疫效应

目的观察基于六钩蚴期的猪囊尾蚴病基因疫苗TSO45W诱导的小鼠体液免疫应答。方法碱裂解法大量制备重组质粒pcDNA3.1-TSO45W及对照质粒pcDNA3.1。将45只雌性昆明小鼠(4~6周)随机分为3组,每组15只。A组(生理盐水组):每只小鼠肌肉注射生理盐水100μl;B组(空质粒pcDNA3.1对照组):每只小鼠肌肉注射空质粒100μg;C组(重组质粒pcDNA3.1-TSO45W组):每只小鼠肌肉注射重组质粒100μg。分别于免疫后2、4、6、8、10周以ELISA方法检测小鼠血清免疫球蛋白IgG,IgM及IgA含量。结果 pcDNA3.1-TSO45-4B免疫组小鼠血清IgG、IgM、IgA均于第4周开始升高,分别为(17.36±1.85)μg/ml、(9.25±1.78)μg/ml和(9.41±0.88)μg/ml,并分别于第8、第6、第8周达到最高,含量分别为(24.26±2.52)μg/ml、(10.69±0.52)μg/ml和(11.22±1.23)μg/ml,与空质粒对照组(B组)和生理盐水对照组(A组)比较差异均有统计学意义(P<0.05)。结论猪囊尾蚴保护性抗原TSO45WDNA疫苗能在小鼠体内诱导体液免疫效应。     

弓形虫ROP1基因真核表达重组质粒免疫小鼠后的免疫应答

目的： 用构建的弓形虫ｐｃＤＮＡ３－ＲＯＰ１ 真核表达重组质粒, 直接免疫小鼠, 观察其所诱导的细胞及体液免疫反应。方法： 碱裂解法大量制备ｐｃＤＮＡ３－ＲＯＰ１ 质粒, 经肌肉注射免疫ＢＡＬＢ／ｃ 小鼠, 每鼠注射１００ μｇ,２ ｗ ｋ 后同量加强免疫１ 次, 以ｐｃＤＮＡ３ 空质粒及生理盐水组为对照。分别于免疫后３０ ｄ、５０ ｄ、７０ ｄ 共３ 次用ＭＴＴ 法测定小鼠脾脏Ｔ 淋巴细胞增殖活性及ＮＫ 细胞活性; 用间接免疫荧光抗体法测定Ｔ淋巴细胞亚群数目;ＥＬＩＳＡ 法测定ＩｇＧ 抗体滴度。结果： 用ｐｃＤＮＡ３－ＲＯＰ１ 质粒免疫小鼠３０ ｄ 后, 脾脏明显增大; 免疫组脾淋巴细胞增殖活性明显高于生理盐水及空质粒对照组。ＮＫ 细胞杀伤活性３ 次的测定结果免疫组均高于对照组。Ｔ 细胞亚群, ＣＤ４＋ 细胞数与对照组相比较无明显变化, 而ＣＤ８＋ 细胞数显著增高。血清抗体ＩｇＧ７０ ｄ 内检测结果, 与对照组相比较, 无明显增高; 而免疫后９０ ｄ 检测明显增高, 抗体滴度１∶１００。结论： 用ｐｃＤＮＡ３－ＲＯＰ１ 重组质粒ＤＮＡ免疫小鼠, 可诱导产生细胞及体液免疫应答。     

日本血吸虫三磷酸甘油醛脱氢酶核酸疫苗小鼠体内的免疫应答特征

目的 研究日本血吸虫大陆株三磷酸甘油醛脱氢酶（GAPDH）基因核酸疫苗免疫C57BL/6小鼠诱生的免疫应答特征和保护性。 方法 将用免疫筛库得到的日本血吸虫大陆株GAPDH编码基因以PCR扩增，扩增产物T-A克隆至载体pT-Adv而后与真核表达载体pcDNA3连接，构建成核酸疫苗（pcDNA3-SjGAPDH）。将纯化的pcDNA3-SjGAPDH经后腿胫前肌免疫C57BL/6小鼠。免疫荧光染色法研究pcDNA3-SjGAPDH在注射的局部肌肉表达特性；用十二烷基硫酸钠?鄄聚丙烯酰胺（SDS-PAGE）、蛋白质印迹法（Western blotting）、ELISA等方法分析pcDNA3-SjGAPDH所诱导的特异性免疫应答特征。 结果 pcDNA3-SjGAPDH免疫后24和48h即可在荧光显微镜下看到C57BL/6小鼠小腿胫前肌的局部肌肉的冰冻切片发出淡绿色荧光，表明有GAPDH蛋白的表达。pcDNA3-SjGAPDH免疫小鼠主要诱生IgG2a、IgG2b和IgG3亚类；免疫小鼠脾淋巴细胞体外经特异性抗原刺激主要诱生γ-干扰素(IFN-γ)和白介素-2(IL-2)细胞因子，未检出IL-4。另外，免疫鼠血清能够识别日本血吸虫SWAP中的天然GAPDH成分。 结论 pcDNA3-SjGAPDH核酸疫苗免疫C57BL/6小鼠主要诱导Th1类型细胞免疫应答。     

HEV ORF3真核表达载体的构建

目的 构建戊型肝炎病毒（HEV） ORF3真核表达载体pcHEV3并进行初步鉴定.方法 从实验感染HEV新疆株的猕猴胆汁中提取HEV RNA,逆转录法合成HEV cDNA,采用RT-PCR方法扩增HEV ORF3 cDNA片段,将其克隆至载体质粒pcDNA3,构建HEV ORF3真核表达载体,经抗生素初步筛选后,重组阳性载体进行酶切和测序鉴定.结果 从实验感染HEV新疆株的猕猴胆汁中克隆出HEV ORF3全长cDNA片段,经酶切鉴定及DNA测序鉴定,成功构建HEV ORF3蛋白真核表达载体pcHEV3.结论 成功构建HEV ORF3蛋白真核表达载体,为进一步研究HEV ORF3蛋白的功能提供了条件.     

细粒棘球绦虫Eg95基因疫苗和重组抗原诱导小鼠免疫应答的比较研究

目的观察比较细粒棘球绦虫Eg95重组抗原和基因疫苗诱导小鼠的免疫应答状况。方法实验组和对照组小鼠分别注射Eg95重组抗原(rEg95)、费氏佐剂(FCA)、pcDNA3-Eg95基因疫苗、pcDNA3质粒和生理盐水,收集各组血清用酶联免疫吸附(ELISA法)检测抗体IgG和IgG2a亚类水平;采集脾细胞用四甲基偶氮唑盐试验(MTT法)检测免疫小鼠的脾淋巴细胞增殖反应。结果rEg95免疫组小鼠在第二次免疫后开始检测到抗Eg95抗原的IgG,并随着免疫次数的增多,血清抗体效价升高,在第1次免疫后第10周时,免疫抗体滴度可达到1∶25,600。Eg95基因疫苗免疫的小鼠产生抗体滴度随免疫次数的增加而升高,最高可达1∶3,200,但是低于Eg95重组蛋白免疫小鼠产生的抗体滴度水平。pcDNA3-Eg95免疫组产生IgG2a亚类抗体水平明显高于对照组和rEg95组。在第四次免疫后,进行淋巴细胞转化试验,MTT法检测证实rEg95和pcD-NA3-Eg95免疫的小鼠,其脾细胞均可在体外被特异性刺激增生。结论细粒棘球绦虫Eg95重组抗原和基因疫苗均可诱发小鼠产生特异性免疫应答。     

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。     

弓形虫抗原与霍乱毒素A2/B亚基复合基因在小鼠体内诱导的免疫反应

目的　观察弓形虫主要表面抗原SAG1、SAG2 与霍乱毒素A2 /B亚基复合基因真核质粒经肌肉免疫小鼠所诱导的免疫反应。方法　将SAG1基因、SAG2 基因及CTXA2 /B基因定向连接插入真核表达质粒pcDNA3.1,经酶切及测序,获得pcDNA3.1 SAG1 SAG2 及pcDNA3.1 SAG1 SAG2 CTXA2 /B的重组子;碱裂解法大量制备经肌肉注射免疫BALB/c鼠,每只鼠经后腿肌肉注射质粒10 0 μg ,每2周免疫1次,共3次,以PcDNA3.1空质粒注射组及PBS组为对照,分别于每次免疫前断尾取血和免疫后4周取小鼠脾脏测定T淋巴细胞增殖活性及NK细胞活性,ELISA法测定IgG抗体。结果　免疫组小鼠的IgG抗体水平明显提高,NK细胞杀伤活性和T细胞增殖活性也明显增强。免疫鼠抗攻击感染的时间延长。结论　含有霍乱毒素的复合基因免疫小鼠后体液免疫和细胞免疫水平均有提高。     

弓形虫主要表面抗原p30单价及复合基因疫苗的构建

目的　构建弓形虫单价基因疫苗 pcDNA3.1-p30及复合基因疫苗 pcDNA3.1-p30-ROP2 ,并比较两种疫苗对小鼠的免疫保护性。　方法　用聚合酶链反应 (PCR)从弓形虫RH株基因组DNA中分别扩增编码弓形虫主要表面抗原 p30和弓形虫棒状体蛋白 2 (ROP2 )的基因片段 ,经T-A克隆 ,将p30单价基因及 p30-ROP2复合基因片段分别插入真核细胞表达载体pcDNA3.1,构建重组真核表达质粒 pcDNA3.1-p30及pcDNA3.1-p30-ROP2。分别免疫BALB/c小鼠 ,设磷酸缓冲盐溶液 (PBS)组、pcDNA3.1空质粒组为对照 ;酶联免疫吸附测定 (ELISA)检测血清特异性IgG抗体 ;弓形虫速殖子腹腔攻击感染观察小鼠生存时间。 　结果　获得 pcDNA3.1-p30、pcDNA3.1-p30-ROP2重组表达质粒 ,用 pcDNA3.1-p30-ROP2免疫的小鼠 ,其IgG抗体吸光度 (A₄₉₀ =2.0 5 1± 0.3 3 7)高于用 pcDNA3.1-p30的吸光度 (A₄₉₀ =1.892± 0.3 69) (P <0.0 5 )。攻击感染弓形虫后小鼠生存时间 ,用 pcDNA3.1-p30-ROP2免疫的小鼠 ,较用 pcDNA3.1-p30的明显延长 (P <0.0 1)。 　结论　弓形虫不同生活阶段的抗原复合基因疫苗较单价基因疫苗具有更好的免疫保护性。     

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.     

日本血吸虫组织蛋白酶B DNA疫苗与IL-4真核表达质粒联合免疫诱导小鼠保护性的研究

目的　观察日本血吸虫组织蛋白酶BDNA疫苗与IL 4真核表达质粒联合免疫小鼠的效果。　方法　将小鼠IL 4基因PCR扩增片段克隆入真核表达载体pcDNA3以构建重组表达质粒。小鼠分为 4组 ,每组 12只 ,实验组 (A)每鼠肌注组织蛋白酶BDNA疫苗和IL 4表达质粒各 10 0 μg ,同时设立组织蛋白酶BDNA疫苗对照组 (B)、IL 4表达质粒对照组 (C)和空载体对照组 (D) ,共免疫 3次。 2周后用免疫组化检测表达质粒在小鼠肌细胞的表达 ,3周后经皮肤攻击感染小鼠 40± 1条日本血吸虫尾蚴。计算减虫和减卵率 ,观察免疫保护性。　结果　重组IL 4质粒和组织蛋白酶BDNA疫苗均在小鼠肌细胞表达。用重组IL 4质粒和组织蛋白酶BDNA疫苗联合免疫诱导小鼠产生 43 .2 0 %的减虫率和 76.63 %的减卵率 ,与组织蛋白酶BDNA疫苗单独免疫比较差异均有显著性 (P <0 .0 0 1,P <0 .0 5 )。　结论　联合IL 4表达质粒免疫可能提高日本血吸虫组织蛋白酶BDNA疫苗的抗血吸虫保护性免疫。     

Sjcb2 DNA疫苗在血吸虫感染小鼠中的保护性作用研究

目的 研究Sjcb2 DNA疫苗在日本血吸虫病小鼠模型中的保护性作用和机制,为血吸虫疫苗的研究提供有效的候选抗原分子。方法 构建pcDNA3.1(+)/Sjcb2 核酸疫苗,将6周龄雌性BALB/c小鼠随机分为pcDNA3.1(+)/Sjcb2 核酸疫苗组、pcDNA3.1(+)空质粒组及生理盐水组,每组35只,采用后腿股四头肌注射方法,每次免疫质粒DNA 100 μg,每2周免疫1次,共免疫3次,用日本血吸虫尾蚴攻击感染各组小鼠。PCR及免疫组化法检测Sjcb2基因在小鼠体内的稳定性及表达情况;MTT法检测小鼠脾淋巴细胞特异性增殖反应;ELISA法检测小鼠血清中Sjcb2抗体水平及攻击感染前后脾淋巴细胞培养上清中IFN-γ和IL-4的水平;计数小鼠荷成虫对数和肝脏荷虫卵数。结果 疫苗组小鼠均可在小鼠肌细胞中检测到Sjcb2基因及其抗原的表达;DNA疫苗组T细胞增殖显著增高(P <0.05);ELISA 结果显示疫苗组IFN-γ 水平显著增高(P <0.05),血吸虫尾蚴攻击感染后各组小鼠IL-4水平显著升高(P <0.05)。DNA疫苗组小鼠荷成虫对数及肝脏荷虫卵数与其它组比较显著性减少(P <0.05),其减虫率为36.32％,减卵率为60.61％。结论 Sjcb2 DNA疫苗接种小鼠后能在小鼠肌细胞中稳定存在和表达;Sjcb2可能通过提高IFN-γ 和降低IL-4水平调节Th1细胞亚群产生抗血吸虫感染的保护性作用。     

日本血吸虫SjC21.7核酸疫苗诱导小鼠保护性免疫作用的研究

目的　研究日本血吸虫中国大陆株 2 1.7k Da膜蛋白分子 (Sj C2 1.7)核酸疫苗对 BAL B/ c小鼠的免疫保护性作用。　方法　采用 PCR方法扩增出特异性 Sj C2 1.7基因的开放阅读框序列 ,在其起始密码子处引入 Kozark序列。将目的基因片段亚克隆到真核表达质粒 pc DNA3.1中 ,构建重组真核表达质粒 Sj C2 1.7- pc DNA3.1。 4 8只 BAL B/ c小鼠分为对照组、实验组和加强组。对照组小鼠的股四头肌注射接种 pc DNA3.1,实验组同法注射重组质粒 Sj C2 1.7- pc D-NA3.1,加强组除注射重组质粒 Sj C2 1.7- pc DNA3.1外 ,同时注射重组质粒 P35 - pc DNA3.1及 P4 0 - pc DNA。每隔 2 wk免疫 1次 ,共免疫 3次。第 3次免疫后第 30天 ,每只鼠感染 4 5± 1条尾蚴 ,4 5 d后剖杀计数各组小鼠成虫数及肝卵数。通过 EL ISA和免疫组化分析观察小鼠免疫学特征的变化。　结果　免疫组化分析显示 ,实验组小鼠股四头肌局部组织有特异性抗原蛋白表达。EL ISA分析表明 ,免疫后实验组和加强组有部分小鼠出现特异性 Ig G抗体。与对照组比较 ,实验组减虫率及减卵率分别为 2 9.9%及 13.8% ,加强组分别为 31.9%及 2 8.0 %。加强组减卵率显著高于实验组(P<0 .0 5 )。　结论　 Sj C2 1.7核酸疫苗能诱导 BAL B/ c小鼠产生一定水平的抗血吸虫感染     

黏膜佐剂大肠埃希菌不耐热肠毒素B亚单位优化的淋病奈瑟菌孔洞蛋白B核酸疫苗的构建及其诱导小鼠的免疫应答

目的 分析黏膜佐剂大肠埃希菌不耐热肠毒素B亚单位(LTB)辅佐的淋病奈瑟菌孔洞蛋白B(PorB)核酸疫苗诱导小鼠的免疫应答水平.方法 PCR法扩增目的 基因porB、ltB、ltB-porB,分别构建3种相应的peDNA3.1(-)真核重组表达载体,经PCR、双酶切及基因测序鉴定后转染Hela细胞,用细胞免疫荧光法鉴定质粒的蛋白表达.将核酸疫苗经鼻饲免疫雌性BALB/c小鼠,检测体液免疫及细胞免疫应答水平,同时用免疫组织化学法检测porB、ltB、ltB-porB基因在小鼠鼻黏膜内的表达.组间均数比较采用方差分析.结果 构建的真核重组质粒均能在Hela细胞内及小鼠鼻黏膜组织内表达.核酸疫苗免疫组小鼠的生殖道灌洗液PorB特异性sIgA及血清porB特异性IgG水平明显高于对照组(P＜0.01;P＜0.05),且ltB-porB融合基因组特异性sIgA明显高于porB组(P＜0.05);pcDNA3.1(-)/porB组小鼠脾淋巴细胞培养上清液中IFN-γ、IL-4和脾淋巴细胞刺激指数(SI)分别为(170.04±23.89)pg/mL、(114.68±14.27)pg/mL和1.68±0.19,pcDNA3.1(-)/ltB-porB组分别为(161.42±27.50)pg/mL、(124.16±19.04)pg/mL和1.73±0.28,均高于对照组pcDNA3.1(-)和PBS,差异均有统计学意义(P＜0.01;P＜0.05),高于对照组pcDNA3.1(-)/ltB,差异均有统计学意义(均P＜0.05),但两核酸疫苗免疫组间差异无统计学意义(均P＞0.05).结论 所构建的核酸疫苗分别在Hela细胞及小鼠鼻黏膜组织内获得了表达,经黏膜途径免疫能诱导小鼠产生较高水平的特异性体液免疫和细胞免疫应答,尤其是黏膜免疫应答;证实黏膜佐剂LTB可辅佐PorB诱导小鼠产生高水平的生殖道黏膜免疫.

Abstract：

Objective To investigate the specific humoral immune response and cellular immune response induced by DNA vaccine with Neisseria gonorrhoeae porin B (PorB) fused with B subunit of Escherichia coli heat-labile enterotoxin B (LTB) in mice. Methods Target genes of porB, ltB and ltB-porB were amplified by polymerase chain reaction (PCR) and cloned into eukaryotic vector pcDNA3.1(-). The recombinants were identified by PCR, enzyme digestion and DNA sequencing.The vectors were transfected into Hela cells, and expressed proteins were checked by cytoimmunofluorescence. Female BALB/c mice were intranasally immunized with recombination vectors. The humoral immune response and cellular immune response were detected by enzyme linked immunosorbent assay (ELISA) and methyl thiazolyl tetrazolium (MTT) colorimetric assay. The expressions of recombination vectors in intranasal mucosal tissues of the immunized mice were detected by immunohistochemistry. The means between groups were compared by analysis of variance. Results All the three recombinants were expressed in Hela cells and intranasal mucosal tissues. The PorB specific IgG in serum and sIgA in vaginal secretions in DNA vaccine immunized mice were significantly higher than those in controls (P＜0.01 ; P＜0.05). Moreover, the sIgA level in pcDNA3.1 (-)/ltB-porB group was higher than that in peDNA3, 1(-)/porB group (P＝0. 002). The levels of interferon-gamma (IFN-γ) and interleukin-4 (IL-4) in the supernatants and stimulation index (SI) of spleen lymphocyte culture in pcDNA3, 1(-)/porB group were (170.04±23.89) pg/mL, (114.68±14.27) pg/mL and 1. 68±0.19, respectively; and those in pcDNA3, 1(-)/ltB-porB group were (161.42±27.50) pg/mL, (124.16±19.04) pg/mL and 1.73±0.28, respectively; which were both higher than those in pcDNA3.1(-)/ phosphate buffered saliae (PBS) group (P＜0. 01; P＜0.05) and pcDNA3.1 (-)/ltB group (all P＜0.05), while there was no significant difference between pcDNA3.1 (-)/ltB-porB group and pcDNA3. 1 (-)/porB group (0. 998, 0. 696, 0. 994; all P＞0.05). Conclusions The constructed DNA vaccines are all successfully expressed in Hela cells and murine intranasal mucosal tissues. The mucosal immunization of the vaccines [pcDNA3. 1 (- )/porB and pcDNA3.1 ( -)/ltBporB] could induce humoral immune response and cellular immune response, especially mucosal immune response. It is confirmed that mucosal adjuvant LTB could promote PorB to induce higher level of mucosal immune response in mice.     

恶性疟原虫重组质粒DNA接种诱导BALB/c小鼠的免疫应答

目的：观察重组质粒DNA直接免疫接种诱导BALB／c小鼠的免疫应答水平，为恶性疟原虫DNA疫苗在动物和人体的应用提供依据。方法：构建编码多价保护性抗原的重组质粒pcDNA3－Pf8，PCR法检测免疫鼠的肌肉、肝脏、肾脏、心脏、脾脏和肺组织中pcDNA3－Pf 8，ELISA、T淋巴细胞转化试验、体外抑制试验观察其诱导的体液免疫及细胞免疫水平。结果：用PCR法从上述组织中均检测到pcDNA3－Pf8，ELISA法测得免疫鼠血清的特异性抗体滴度达12560，淋巴细胞转化试验显示恶性疟原虫可溶性抗原能特异性地剌激免疫鼠脾细胞增殖，免疫血清在体外还能抑制恶性疟红内期疟原虫的生长、发育。结论：编码恶性疟原虫多价保护性抗原的重组质粒pcDNA 3-Pf 8 直接免疫接种, 能特异性地剌激BALB/c 小鼠产生体液免疫和细胞免疫应答, 其免疫血清在体外对疟原虫生长发育具有明显抑制作用。     

弓形虫ROP2-P30重组真核表达质粒的构建及其免疫效应的初步分析

目的构建弓形虫棒状体蛋白2（ROP2）和膜表面蛋白1（P30）融合的重组真核表达质粒,观察融合抗原ROP2-P30以DNA免疫方式在体内的免疫学效应。方法以重组质粒pET28b/ROP2-P30为模板,利用分子克隆技术构建重组真核表达质粒pcDNA3.1/ROP2-P30,经PCR和酶切鉴定正确后,体外转染COS-7细胞,Westernblot检测ROP2-P30表达。重组质粒pcDNA3.1/ROP2-P30以每鼠100μg混合透明质酸酶10U的剂量肌肉注射免疫BALB/c雌性小鼠,以弓形虫虫体裂解抗原作包被抗原,ELISA法测定免疫小鼠血清IgG抗体,免疫结束2周后,以约100个弓形虫速殖子攻击感染小鼠,观察小鼠生存状况。结果PCR和酶切鉴定表明重组质粒pcDNA3.1/ROP2-P30构建正确;Westernblot显示该重组质粒在COS-7细胞中瞬时表达的产物可被重组ROP2-P30免疫兔血清识别;ELISA检测重组质粒免疫小鼠血清特异性IgG抗体水平升高;重组质粒免疫小鼠感染弓形虫后的存活时间较对照组有所延长。结论重组真核表达质粒pcDNA3.1/ROP2-P30构建成功,用该重组质粒DNA直接免疫小鼠,能够诱导产生特异的体液免疫反应,具有一定的免疫保护性;该重组质粒表达的融合抗原分子ROP2-P30具有免疫原性,可作为疫苗候选抗原深入研究。     

弓形虫和乙型肝炎病毒混合核酸疫苗的研究Ⅲ.pcDNA3-HBsAg-GRA1免疫小鼠的保护性观察

目的观察重组质粒pcDNA3HBsAgGRA1DNA接种诱导的保护性免疫应答。方法质粒DNA免疫BALB/c小鼠;ELISA法检测GRA1、HBsAg抗体及亚类水平;提取各免疫组小鼠肌肉组织DNA进行PCR检测;弓形虫RH强毒株攻击感染各免疫组小鼠。结果经pcDNA3HBsAgGRA1免疫组小鼠产生抗GRA1和HBsAg抗体,且抗GRA1的抗体水平明显高于GRA1单独和GRA1与HBsAg混合免疫组。弓形虫RH强毒株攻击感染pcDNA3HBsAgGRA1免疫组小鼠,其存活时间明显长于其他各组,结果提示HBsAg可能起免疫佐剂作用。结论将GRA1与HBsAg融合明显增强了GRA1的免疫原性和保护性。     

Induction of hepatitis C virus-specific cytotoxic T and B cell responses by dendritic cells expressing a modified antigen targeting receptor

AIM: To find a novel antigen (Ag) presentation strategy to improve the immune responses induced by dendritic cell (DC) vaccine expressing hepatitis C virus (HCV) core antigen (pcDNA3HCV C-Fc) in Balb/c mice (H-2d). METHODS: pcDNA3HCV C-Fc plasmid and eukaryotic expression vector pcDNA3 were injected into mice sc. Immune responses to pcDNA3HCV C-Fc were studied. Meanwhile the effect of pcDNA3HCV C-Fc on anti-translated subcutaneous tumor of SP2/0 cells stably expressing HCV C Ag (SP2/0-HCV C-FC) was also studied. Anti-HCV C in serum was detected by enzyme-linked immunoadsordent assay (ELISA) and HCV specific cytotoxic T lymphocyte (CTL) activity was measured by LDH release assay. After 3 wk of DNA immunization, the cells of SP2/0-HCV C-FC were inoculated into mice subcutaneously and tumor growth was measured every 5 d. The survival rate and living time of mice were also calculated. RESULTS: After 4 wk of DC immunization, the A450 nm values of sera in mice immunized with pcDNA3HCV C-Fc-DC and pcDNA3-DC were 0.56±0.17 and 0.12±0.03 respectively. The antibody titres in mice codeliveried with pcDNA3HCV C-Fc with DC were significantly higher than those of mice injected with pcDNA3-DC. The HCV specific CTL activities in mice coinjected with DC and pcDNA3HCV C-Fc or empty expression vectors were(73.2±3.1) % and (24.4±8.8) % , which were significantly higher than those of mice injected with water. The DC vaccine could evidently inhibit tumor growth, prolong the survival time of mice and improve the survival rate of mice and these effects could be improved by HCV C-Fc (pcDNA3HCV C-Fc) gene codelivered. CONCLUSION: DC vaccine has a strong antigenicity in humoral and cellular immunities, which can be promoted by transduced pcDNA3HCV C-Fc expressing HCV C or Fc. Thus, pcDNA3HCV C-Fc-transduced DCs may be a promising candidate for a CTL-based vaccine against HCV.     

含弓形虫ROP1基因真核表达重组质粒DNA免疫小鼠的研究Ⅲ.免疫鼠肌组织表达产物免疫酶法定位及血清IgG抗体测定

目的　用所构建的弓形虫ｐｃＤＮＡ３－ＲＯＰ１ 真核表达重组质粒,经肌肉注射免疫小鼠,观察它在肌组织中的表达及不同免疫途径所诱导的体液免疫应答。方法　碱裂解法大量制备ｐｃＤＮＡ３－ＲＯＰ１ 质粒,免疫ＢＡＬＢ／ｃ小鼠,每只鼠注射１００ｕｇ,两周后同量加强免疫一次,以ｐｃＤＮＡ３ 空质粒及生理盐水组为对照。于免疫后第５０ 天用间接免疫酶法检测注射局部肌组织重组蛋白的表达;ＥＬＩＳＡ法测定ＩｇＧ抗体滴度。结果　免疫鼠肌组织石蜡切片呈特异性阳性反应;血清ＩｇＧ抗体９０天后测定为阳性;皮下及肌肉不同免疫途径血清均显示阳性结果,无显著性差异。结论　ｐｃＤＮＡ３－ＲＯＰ１质粒ＤＮＡ 免疫小鼠后,肌组织内有重组蛋白表达,并能诱导机体产生ＩｇＧ抗体     

恶性疟原虫FCC-1/HN株pcDNA_3-Pfs25重组质粒在小鼠体内的免疫应答

目的　探讨恶性疟原虫ＤＮＡ 疫苗在小鼠体内的免疫反应。方法　将恶性疟原虫ＦＣＣ－ １／ＨＮ株有性期阶段的重组质粒ｐｃＤＮＡ３－ Ｐｆｓ２５ 经骨骼肌途径注射ＢＡＬＢ／ｃ小鼠,对注射部位的骨骼肌进行了预处理,即于注射前７ｄ 先在左后肢股四头肌注射０．５％ 盐酸布比卡因５０μｌ,注射深度为２ｍ ｍ 。观察免疫后不同时间点小鼠血清ＩｇＧ抗体滴度、脾淋巴细胞增殖反应、ＣＤ４＋ ／ＣＤ８＋ Ｔ细胞亚群比值和ＮＫ 细胞杀伤活性的变化。结果　１）重组质粒ｐｃＤＮＡ３－ Ｐｆｓ２５ 经肌肉注射途径免疫小鼠后,机体ＩｇＧ抗体滴度增高、特异性Ｔ淋巴细胞增殖反应增强、ＣＤ８＋ Ｔ细胞亚群比值增高以及ＮＫ细胞杀伤活性增强。２）肌肉注射为一有效的ＤＮＡ疫苗免疫途径。结论　采用编码有性期基因的重组质粒ｐｃＤＮＡ３－ Ｐｆｓ２５ 经骨骼肌注射途径免疫小鼠,能诱导机体有效的体液免疫、细胞免疫和ＮＫ细胞杀伤活性。本研究为恶性疟ＤＮＡ疫苗的研究提供了免疫学实验依据