弓形虫SAG1-ROP2-SAG2复合基因疫苗与免疫佐剂pmIL-12对小鼠的免疫保护性研究
发布时间：2018-08-09 15:36
【摘要】： 弓形虫是一种分布广泛的、专性细胞内寄生机会致病原虫,可感染人及多种动物的有核细胞。弓形虫感染人体后可侵犯多种脏器和组织并可通过母婴垂直传播而造成胎儿畸形、神经系统发育障碍、脉络膜视网膜炎等引起流产、早产甚至死胎。对免疫功能低下者如艾滋病患者是致死主要病因。此外,弓形虫病也给畜牧业生产造成严重的经济损失。因此,为了有效的防治弓形虫,疫苗的研制已成为预防及治疗弓形虫病的发展方向。 在研究有关弓形虫疫苗的过程中,发展多种抗原组合、针对不同生活史发育阶段的复合多价疫苗是研究弓形虫疫苗过程中的一个发展方向与共识,这有助于克服单一抗原成分作为候选疫苗的不足。SAG1抗原作为弓形虫速殖子期特异的主要表面抗原之一,具有高度的免疫原性和免疫保护性,是弓形虫感染免疫诊断和疫苗开发的的主要候选抗原。ROP2蛋白是弓形虫棒状体分泌的一种蛋白,主要协助虫体入侵宿主细胞,在弓形虫生活史的速殖子期、缓殖子期和子孢子期中均有表达,具有高度的保守性和免疫原性。SAG2抗原为速殖子膜表面的另一重要抗原,与弓形虫入侵宿主细胞有密切的关系,到目前为止,对弓形虫SAG_2蛋白的功能研究较少,SAG_2蛋白可以使弓形虫固定于有核细胞的表面,并辅助弓形虫进入有核细胞,介导弓形虫速殖子的入侵过程。 同时,为攻克核酸疫苗免疫效力低下的难题,我们选用小鼠白介素12(mIL-12)的真核表达质粒作为基因佐剂,以增强弓形虫复合抗原基因SAG1-ROP2-SAG2的免疫效果。在弓形虫感染早期IL-12可强烈刺激NK细胞和T细胞分泌IFN-γ,继之激活巨噬细胞提高其杀伤弓形虫活力,也能促进CD4~+T细胞向Th1细胞分化,并增强NK细胞和CD8~+T细胞杀伤功能。同时,IL-12对促进IFN-γ的持续产生也起到重要作用。因此IL-12的表达在弓形虫感染的急慢性期均起到重要作用。 本研究选用弓形虫复合抗原基因SAG1-ROP2-SAG2及基因佐剂mIL-12通过肌注方式免疫小鼠,观察并研究其免疫保护性。结果表明复合基因疫苗的免疫效果明显优于单基因疫苗SAG2及双基因疫苗SAG1-ROP2,并且IL-12可以对该复合基因疫苗起到很好的免疫增强作用。在弓形虫研究领域,国内外尚无此项研究报道。
[Abstract]:Toxoplasma gondii (Toxoplasma gondii) is a widely distributed opportunistic protozoa that infects human and many animals. Toxoplasma gondii infection can invade various organs and tissues and cause fetal malformation, nervous system dysplasia, choroidal retinitis, abortion, premature delivery and even stillbirth through vertical transmission from mother to child. For people with low immune function such as AIDS is the main cause of death. In addition, toxoplasmosis also causes serious economic loss to animal husbandry production. Therefore, in order to effectively control Toxoplasma gondii, the development of vaccine has become the development direction of prevention and treatment of toxoplasmosis. In the course of studying Toxoplasma gondii vaccine, the development of multiple antigen combinations and the development of multiple multivalent vaccines at different stages of life cycle development is a development direction and consensus in the research of Toxoplasma gondii vaccine. SAG1 antigen, one of the major surface antigens specific to Toxoplasma gondii tachyzoites, has a high degree of immunogenicity and protection. ROP2 protein, the main candidate antigen for Toxoplasma gondii infection diagnosis and vaccine development, is a protein secreted by Toxoplasma gondii corybodies, which mainly assists the parasites to invade host cells during the tachyzoite stage of Toxoplasma gondii's life cycle. Both bradyzoites and sporozoites are expressed. SAG2 antigen is another important antigen on the surface of Toxoplasma gondii and has a close relationship with the invasion of host cells by Toxoplasma gondii so far. The function of SAG_2 protein of Toxoplasma gondii was studied. The SAG-2 protein could immobilize Toxoplasma gondii on the surface of nucleated cells, and assist Toxoplasma gondii to enter into nucleated cells and mediate the invasion of Toxoplasma Toxoplasma tachyzoites. In order to overcome the problem of low immune efficiency of nucleic acid vaccine, the eukaryotic expression plasmid of mouse interleukin 12 (mIL-12) was selected as gene adjuvant to enhance the immune effect of Toxoplasma gondii complex antigen gene SAG1-ROP2-SAG2. During the early stage of Toxoplasma gondii infection, IL-12 stimulated the secretion of IFN- 纬 by NK cells and T cells, and then activated macrophages to enhance the cytotoxicity of Toxoplasma gondii. It also promoted the differentiation of CD4T cells into Th1 cells and enhanced the killing function of NK cells and CD8T cells. At the same time, IL-12 also plays an important role in promoting the sustained production of IFN- 纬. Therefore, the expression of IL-12 plays an important role in the acute and chronic stage of Toxoplasma gondii infection. In this study, Toxoplasma gondii complex antigen gene SAG1-ROP2-SAG2 and gene adjuvant mIL-12 were used to immunize mice by intramuscular injection. The results showed that the immune effect of the composite gene vaccine was significantly better than that of the single gene vaccine SAG2 and the double gene vaccine SAG1-ROP2.The IL-12 could play a good role in enhancing the immunity of the compound gene vaccine. In the field of Toxoplasma gondii, there is no such research report at home and abroad.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：R392
本文编号：2174544
[Abstract]:Toxoplasma gondii (Toxoplasma gondii) is a widely distributed opportunistic protozoa that infects human and many animals. Toxoplasma gondii infection can invade various organs and tissues and cause fetal malformation, nervous system dysplasia, choroidal retinitis, abortion, premature delivery and even stillbirth through vertical transmission from mother to child. For people with low immune function such as AIDS is the main cause of death. In addition, toxoplasmosis also causes serious economic loss to animal husbandry production. Therefore, in order to effectively control Toxoplasma gondii, the development of vaccine has become the development direction of prevention and treatment of toxoplasmosis. In the course of studying Toxoplasma gondii vaccine, the development of multiple antigen combinations and the development of multiple multivalent vaccines at different stages of life cycle development is a development direction and consensus in the research of Toxoplasma gondii vaccine. SAG1 antigen, one of the major surface antigens specific to Toxoplasma gondii tachyzoites, has a high degree of immunogenicity and protection. ROP2 protein, the main candidate antigen for Toxoplasma gondii infection diagnosis and vaccine development, is a protein secreted by Toxoplasma gondii corybodies, which mainly assists the parasites to invade host cells during the tachyzoite stage of Toxoplasma gondii's life cycle. Both bradyzoites and sporozoites are expressed. SAG2 antigen is another important antigen on the surface of Toxoplasma gondii and has a close relationship with the invasion of host cells by Toxoplasma gondii so far. The function of SAG_2 protein of Toxoplasma gondii was studied. The SAG-2 protein could immobilize Toxoplasma gondii on the surface of nucleated cells, and assist Toxoplasma gondii to enter into nucleated cells and mediate the invasion of Toxoplasma Toxoplasma tachyzoites. In order to overcome the problem of low immune efficiency of nucleic acid vaccine, the eukaryotic expression plasmid of mouse interleukin 12 (mIL-12) was selected as gene adjuvant to enhance the immune effect of Toxoplasma gondii complex antigen gene SAG1-ROP2-SAG2. During the early stage of Toxoplasma gondii infection, IL-12 stimulated the secretion of IFN- 纬 by NK cells and T cells, and then activated macrophages to enhance the cytotoxicity of Toxoplasma gondii. It also promoted the differentiation of CD4T cells into Th1 cells and enhanced the killing function of NK cells and CD8T cells. At the same time, IL-12 also plays an important role in promoting the sustained production of IFN- 纬. Therefore, the expression of IL-12 plays an important role in the acute and chronic stage of Toxoplasma gondii infection. In this study, Toxoplasma gondii complex antigen gene SAG1-ROP2-SAG2 and gene adjuvant mIL-12 were used to immunize mice by intramuscular injection. The results showed that the immune effect of the composite gene vaccine was significantly better than that of the single gene vaccine SAG2 and the double gene vaccine SAG1-ROP2.The IL-12 could play a good role in enhancing the immunity of the compound gene vaccine. In the field of Toxoplasma gondii, there is no such research report at home and abroad.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：R392
【参考文献】
相关期刊论文 前5条
1 孙怡;何深一;丛华;杨婷婷;周怀瑜;古钦民;李瑛;赵群力;;弓形虫SAG1-SAG2复合DNA疫苗免疫小鼠诱导的免疫保护性[J];国际医学寄生虫病杂志;2006年01期
2 张洪花,韩广东,王昌源,刘湘萍,闫歌,刘玉冰,刘凤梅,傅斌,贾凤菊,辛福敏,岳继娥;弓形虫抗原的保护性研究[J];中国寄生虫病防治杂志;2001年01期
3 郭虹,陈观今,郑焕钦,周永安,吕芳丽;弓形虫ROP1基因真核表达重组质粒免疫小鼠后的免疫应答[J];中国寄生虫学与寄生虫病杂志;1999年06期
4 高世同,吴少庭,林敏,占国清,郑春福;弓形虫P22编码基因真核表达质粒接种小鼠后的细胞免疫效果[J];中国人兽共患病杂志;2000年06期
5 杨婷婷,何深一,张加勤,周怀瑜,丛华,古钦民,李瑛,赵群力;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[J];中国人兽共患病杂志;2005年05期
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