本文選題：弓形蟲 + 復(fù)合基因疫苗��； 參考：《山東大學(xué)》2010年碩士論文

【摘要】： 弓形蟲是一種廣泛寄生于人和動物有核細(xì)胞內(nèi)的寄生原蟲,可以感染包括人類在內(nèi)的所有哺乳動物,此蟲呈世界性分布,人群感染率相當(dāng)高,許多國家的平均感染率在25%-50%。弓形蟲侵襲的細(xì)胞種類多,累及器官廣泛,臨床表現(xiàn)復(fù)雜。在免疫抑制或免疫缺陷患者中(如器官移植、惡性腫瘤、AIDS、長期使用免疫抑制劑等)可引起嚴(yán)重的器官損害(多見于腦和眼)。先天性感染是弓形蟲通過母嬰傳播的,可引起胎兒流產(chǎn)、死胎或畸胎,是造成兒童先天畸形、弱智及智力發(fā)育遲緩的重要原因之一。此外,弓形蟲病也給畜牧業(yè)生產(chǎn)造成嚴(yán)重的經(jīng)濟(jì)損失。迄今尚無治療弓形蟲病的特效藥物,因此研制安全有效的疫苗極為迫切。 大量的動物和人體實(shí)驗(yàn)表明,DNA疫苗不僅可以預(yù)防,還可以治療病原生物的感染。由于弓形蟲生活史較復(fù)雜,抗原成分具有發(fā)育階段的特異性或差異性。因此在研究有關(guān)弓形蟲疫苗的過程中,發(fā)展多種抗原組合、針對不同生活史發(fā)育階段的復(fù)合多價(jià)疫苗是研究弓形蟲疫苗過程中的一個(gè)發(fā)展方向與共識,這有助于克服單一抗原成分作為候選疫苗的不足。 SAG1抗原作為弓形蟲速殖子表面的主要抗原之一,具有高度的免疫原性和免疫保護(hù)性,是迄今應(yīng)用最多的弓形蟲疫苗候選抗原。SAG1蛋白分布于弓形蟲速殖子表膜、速殖子內(nèi)以及納蟲泡的管狀結(jié)構(gòu)中,是誘導(dǎo)宿主免疫應(yīng)答的主要靶抗原。能夠誘導(dǎo)機(jī)體產(chǎn)生IgG, IgM, IgE, IgA及sIgA,并可誘導(dǎo)細(xì)胞因子產(chǎn)生。 ROP2蛋白是弓形蟲棒狀體分泌的一種蛋白,存在于弓形蟲速殖子、緩殖子及包囊期,它可誘導(dǎo)機(jī)體產(chǎn)生以IgA, IgM, IgG為主的體液免疫,還可被人特異性T細(xì)胞克隆識別而產(chǎn)生高水平的IFN-γ。SAGl和ROP2在蟲體入侵宿主的過程中相互促進(jìn),其相應(yīng)的抗體可有效拮抗弓形蟲感染。 DNA疫苗誘導(dǎo)體液免疫和細(xì)胞免疫的效率相對較低,尤其是在大型動物和人類中,影響了它的實(shí)際應(yīng)用。我們選用大腸埃希菌腸毒素B亞基(LTB)真核表達(dá)質(zhì)粒作為基因佐劑,以增強(qiáng)弓形蟲復(fù)合抗原基因SAG1-ROP2的免疫效果。 LT是由產(chǎn)腸毒素E. coli分泌并存在于菌體周質(zhì)中的一種外毒素,由A、B兩種亞單位組成,其中B亞單位既有較強(qiáng)的免疫原性,又有較強(qiáng)的黏膜佐劑效應(yīng),且毒力小、安全性高,是最有潛力的黏膜免疫佐劑之一�？诜捅莾�(nèi)接種LT均可誘導(dǎo)黏膜和全身性的免疫應(yīng)答,有效增強(qiáng)抗原蛋白的免疫原性。 該研究選用弓形蟲復(fù)合抗原基因SAG1-ROP2及基因佐劑LTB通過黏膜方式免疫小鼠,觀察并研究其免疫保護(hù)性。結(jié)果表明復(fù)合基因疫苗的免疫效果明顯優(yōu)于單基因疫苗SAG1及ROP2, LTB可以對該復(fù)合基因疫苗起到很好的免疫增強(qiáng)作用。在弓形蟲研究領(lǐng)域,國內(nèi)外尚無此項(xiàng)研究報(bào)道。
[Abstract]:Toxoplasma gondii (Toxoplasma gondii) is a parasitic protozoa widely parasitic in the nucleated cells of humans and animals. It can infect all mammals including human beings. The infection rate of Toxoplasma gondii is very high in the world. The average infection rate in many countries ranges from 25 to 50. Toxoplasma gondii invades many types of cells, involving a wide range of organs, and complex clinical manifestations. In immunosuppressive or immunodeficient patients (e.g. organ transplantation, malignant tumor AIDS, long-term use of immunosuppressive agents, etc.), severe organ damage can be caused (more commonly seen in the brain and eyes). Congenital infection is transmitted from mother to child by Toxoplasma gondii, which can cause abortion, stillbirth or teratogenesis. It is one of the important causes of congenital malformation, mental retardation and mental retardation in children. In addition, toxoplasmosis also causes serious economic loss to animal husbandry production. There is no effective drug for Toxoplasma gondii so it is urgent to develop a safe and effective vaccine. A large number of animal and human experiments have shown that DNA vaccine can not only prevent, but also treat the infection of pathogenic organisms. Because of the complex life history of Toxoplasma gondii, the antigen components have the specificity or difference of development stage. Therefore, in the research of Toxoplasma gondii vaccine, the development of a variety of antigen combinations, for different stages of life cycle development of the complex multivalent vaccine is a development direction and consensus in the research process of Toxoplasma gondii vaccine. SAG1 antigen, one of the major antigens on the surface of Toxoplasma gondii tachyzoites, is highly immunogenicity and immunogenicity. Toxoplasma gondii vaccine candidate antigen. SAG1 protein is widely used in Toxoplasma gondii Tachyzoites epidermis, tachyzoites and the tubular structure of nalcidia vesicles, and is the main target antigen to induce host immune response. It can induce the production of IgG, IgM, IgE, IgA and Siga, and induce cytokine production. ROP2 protein is a kind of protein secreted by Toxoplasma gondii rodlike body, which exists in Toxoplasma gondii tachyzoites, bradyzoites and cysts. It can induce humoral immunity mainly composed of IgA, IgM and IgG, and can be recognized by human specific T cell clone to produce high levels of IFN- 緯. SAGl and ROP2, which promote each other in the process of invading the host. The efficiency of DNA vaccine in inducing humoral and cellular immunity was relatively low, especially in large animals and humans, which affected its practical application. The eukaryotic expression plasmid of Escherichia coli enterotoxin B subunit LTB was used as gene adjuvant. In order to enhance the immune effect of Toxoplasma gondii complex antigen gene SAG1-ROP2, LT is an exotoxin secreted by enterotoxin E. coli, which is composed of two subunits of Agna B, and exists in the peripheral cytoplasm of Toxoplasma gondii (Toxoplasma gondii). The B subunit has both strong immunogenicity and strong mucosal adjuvant effect. It is one of the most potential mucosal adjuvants with low virulence and high safety. Oral and nasal inoculation with LT could induce mucosal and systemic immune responses and enhance the immunogenicity of antigenic proteins. In this study mice were immunized with SAG1-ROP2 and LTB by mucosal method to observe and study the immune protection of Toxoplasma gondii complex antigen gene SAG1-ROP2 and gene adjuvant LTB. The results showed that the immune effect of the composite gene vaccine was significantly better than that of the single gene vaccine SAG1 and ROP2LTB could enhance the immune response of the vaccine. In the field of Toxoplasma gondii, there is no such research report at home and abroad.
【學(xué)位授予單位】：山東大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2010
【分類號】：R392

【引證文獻(xiàn)】

相關(guān)期刊論文 前1條

1 劉秀華;李英豪;苑文英;藏愛民;田因詩;余瑞欣;周雅靜;;弓形蟲單基因和復(fù)合基因疫苗的研究進(jìn)展[J];中國人獸共患病學(xué)報(bào);2011年11期

，

本文編號：2047617