密码修饰可增强沙眼衣原体MOMP DNA质粒免疫小鼠的免疫应答

目的探讨密码修饰对沙眼衣原体主要外膜蛋白(MOMP)基因表达和DNA质粒免疫的影响。方法根据人类密码子使用偏好对鼠肺炎沙眼衣原体(Chlamydia trachomatis mouse pneumoni-tis)MOMP基因进行优化修饰,设计合成人源化MOMP基因(HuMOMP)。构建以pcDNA3为载体的含HuMOMP及含野生型MOMP基因(WtMOMP)的真核表达质粒。瞬时转染COS-1细胞,Western blot方法比较HuMOMP基因及WtMOMP基因在哺乳动物细胞中的蛋白表达水平。DNA质粒肌内免疫BALB/c小鼠,检测小鼠血清特异性抗体、DTH和淋巴细胞增殖反应,比较优化密码MOMP基因和野生型MOMP基因DNA质粒免疫的免疫效果。结果人工合成HuMOMP基因,成功构建重组真核表达质粒pcDNA3-HuMOMP及pcDNA3-WtMOMP。转染细胞Western blot结果显示,HuMOMP基因的蛋白表达水平明显高于WtMOMP基因。ELISA结果表明,HuMOMP DNA质粒免疫组小鼠血清特异性IgG抗体有所升高;细胞免疫检测结果显示,HuMOMP DNA质粒免疫组小鼠足垫肿胀程度增强、淋巴细胞增殖实验刺激指数(SI)增高,两者与WtMOMP DNA质粒免疫组相比P<0.05,差异均有统计学意义。结论人源化密码修饰能够增强沙眼衣原体MOMP基因在哺乳动物细胞中的蛋白表达及DNA质粒免疫小鼠的免疫反应,这对于新型衣原体DNA疫苗的研究具有重要意义。

Construction of DNA Vaccine for FMDV P1 Gene and Immunization Experiment

[Objective] This study aimed to construct DNA vaccine of foot-and-mouth disease （FMD）.[Method] Plasmid carriers plESZP1 and pUTK3CP1 with PRV were constructed for FMDV P1 gene expression.Mice were immunized,and their antibody level was detected.The two eukaryotic expression plasmids constructed were transfected into Vero cells.PCR,IFA and Westem-blot were carried out to detect the transcription and expression of the objective gene.Balb/C mice were intramuscularly inoculated with the DNA plasmid which expressed the target gene correctly,and the antibody level in mice was detected by the means of ELISA and serum neutralization （SN）.[Result] DNA plasmid carrying P1 gene which encodes FMDV capsid protein caused specific body fluid immunoreaction in mice,and the antibody level of anti-FMDV had no difference in the mice induced by the two recombinant plasmids.[Conclusion] This study lays a foundation for evaluating the genetically modified vaccine by immunizing animals with recombinant PRV containing the FMDV P1 gene and recombinant virus.

Molecular mechanism of immune response induced by foreign plasmid DNA after oral administration in mice

AIM： TO study immune response induced by foreign plasmid DNA after oral administration in mice.METHODS： Mice were orally administered with 200 μg of plasmid pcDNA3 once and spleen was isolated 4 h and 18 h after administration. Total RNA was extracted from spleen and gene expression profile of BALB/c mice spleen was analyzed by using Affyrnetrix oligonucleotide GeneChip. Functional cluster analysis was conducted by GenNAPP software.RESULTS： At 4 h and 18 h after oral plasmid pcDNA3 administration, a number of immune-related genes, including cytokine and cytokine receptors, chemokines and chemokine receptor, complement molecule, proteasome, histocompatibility molecule, lymphocyte antigen complex and apoptotic genes, were upregulated. Mloreover, MAPPFinder results also showed that numerous immune response processes were upregulated. In contrast, the immunoglobulin genes were down-regulated.CONCLUSION： Foreign plasmid DNA can modulate the genes expression related to immune system via the gastrointestinal tract, and further analysis of the related immune process may help understand the molecular mechanisms of immune response induced by foreign plasmid via the gastrointestinal tract.

Potent T cell Responses Induced by Single DNA Vaccine Boosted with Recombinant Vaccinia Vaccine

Plasmid DNA, an effective vaccine vector, can induce both cellular and humoral immune responses. However, plasmid DNA raises issues concerning potential genomic integration after injection. This issue should be considered in preclinical studies. Tiantan vaccinia virus (TV) has been most widely utilized in eradicating smallpox in China. This virus has also been considered as a successful vaccine vector against a few infectious diseases. Potent T cell responses through T-cell receptor (TCR) could be induced by three injections of the DNA prime vaccine followed by a single injection of recombinant vaccinia vaccine. To develop a safer immunization strategy, a single DNA prime followed by a single recombinant Tiantan vaccinia (rTV) AIDS vaccine was used to immunize mice. Our data demonstrated that one DNA prime/rTV boost regimen induced mature TCR activation with high functional avidity, preferential T cell Vβ receptor usage and high sensitivity to anti-CD3 antibody stimulation. No differences in T cell responses were observed among one, two or three DNA prime/rTV boost regimens. This study shows that one DNA prime/rTV boost regimen is sufficient to induce potent T cell responses against HIV.

鸡Stra8基因真核表达载体构建及亚细胞定位的研究

试验旨在克隆苏禽黄鸡视黄酸激活基因8(Stra8)的cDNA序列,构建pEGFP-C1-Stra8载体并制备鸡Stra8抗体。通过RT-PCR克隆苏禽黄鸡Stra8基因cDNA,构建pEGFP-C1-Stra8和pcDNA3.1(+)-Stra8重组质粒,分别转染NIH-3T3细胞和免疫小鼠制备抗体,间接免疫荧光法检测抗体效价以及在细胞中的分布。结果显示,苏禽黄鸡Stra8基因cDNA全长645bp,共编码214个氨基酸,提交至GenBank获得登录号为JX204292.1;成功制备Stra8多克隆抗体,pEGFP-C1-Stra8融合蛋白在NIH-3T3细胞质中表达。该结果为深入探讨禽类Stra8生物学功能奠定了基础。

Anti-tumor Immunity of Gene Vaccine with Nucleofection Technology

OBJECTIVE To observe enhancement of anti-tumor immunity by gene vaccine using nucleofection technology METHODS The technique of nucleofection was used to transfer effectively plasmid DNA into immature dendritic cells （iDCs）; we studied immune responses regulated by DNA vaccine using real-time quantitative polymerase chain reaction （PCR） and western-blotting to optimize the follow-up lymphocyte activation. The anti-tumor capacity of lymphocytes primed by DCs was analyzed using lactate dehydrogenase with a non-radioactive cytotoxicity assay.

Construction of a recombinant plasmid harbouring the rhoptry protein 1 gene of Toxoplasma gondii and preliminary observations on DNA immunity

Objective To observe the immune responses elicited in BALB/c mice by a DNA vaccine. A gene encoding rhoptry protein 1 (ROP1) from Toxoplasma gondii (T. gondii) was cloned into vector pcDNA3. Methods Amplifyied gene fragments coding for ROP1 from the genomic DNA of T.gondii ZS2 were inserted into cloning vector, pUC18, and sub-cloned into pcDNA3. Mice were injected at a dosage of 100?μg recombinant plasmid DNA by intramuscular injection and boosted after 2 weeks. pcDNA3 and normal saline were used as control. 30, 50 and 70 days after the second immunization, NK cell activity, T lymphocyte proliferation and sub-clusters and serum IgG antibody were assayed.Results The specific gene fragment coding for ROP1 was amplified and a pcROP1 recombinant was constructed. At 30 days after immunization, the spleens of the mice were obviously enlarged evidently. NKC activity and the proliferation of spleen T lymphocytes seen on MTT assay were higher in pcROP1 group than in the controls. The number of CD4+ T cells exhibited no obvious increase compared with that of the control, but CD8+ T cells were obviously increased (P<0.05). At 90 days after vaccination, the titer of IgG antibody in the serum of vaccinated mice was positive (1∶100). Conclusion pcROP1 was constructed and it could elicit both cellular and humoral immune responses in immunized mice.

STING-mediated DNA sensing in cancer immunotherapy

While STING(STimulator of INterferon Genes) has been shown to be essential for cytosolic DNA-triggered innate immune activation, accumulated evidence obtained from various studies suggested that an intrinsic relevance of STING-associated signaling in tumorigenesis can be observed. Also, several clinical trials using immunostimulatory adjuvants, particularly agonistic as well as non-agonistic ligands for STING, have revealed their therapeutic potential not only as vaccine adjuvants but also as anti-tumor agents. However, cases have also been reported where the involvement of STING shows a protective role in tumor growth. Here we summarize recent findings that have pointed towards the STING pathway as an innate immune sensing mechanism driving type I interferon production in the tumor context. Better understanding of this pathway can guide further development of novel immunotherapeutic strategies in the treatment of cancer.