【作者】 唐明；

【导师】 苗季；

【作者基本信息】 厦门大学 ， 生物化学与分子生物学， 2009， 硕士

【摘要】 戊型肝炎是由戊型肝炎病毒引起的、经消化道传播的急性肝炎,在发展中国家及发达国家均有流行。越来越多的研究证据表明戊型肝炎为人兽共患病,其病毒潜在由动物到人的交叉感染而导致传播的危险,这使得戊型肝炎逐渐成为严重威胁人类健康的疾病。由于至今尚未建立有效的病毒分离方法和细胞培养模型,也缺乏便捷实用的动物模型,国内外学者对戊型肝炎病毒的研究还不够充分。为提供更有效的疾病防治方案,人们迫切需要研究清楚戊型肝炎病毒的抗原表位结构和免疫应答机制。本研究首先利用针对戊型肝炎病毒的抗体库,采用基于改造蛋白和重叠肽库的表位鉴定技术、抗体竞争抑制性分析、抗体免疫捕获病毒分析、基于重组衣壳蛋白吸附细胞模型或病毒结合细胞模型的抗体性质分析等方法,较详尽地考察抗体的各种性质。其次,分析对比了代表性表位,进行了序列比对、表位突变分析,这对认识戊型肝炎病毒复杂的抗原表位和疫苗设计有着重要的意义。再次,利用颗粒性蛋白载体构建表位融合蛋白从而充分地展示了表位,发现了其中12A10抗体对应的非优势表位具有一定的中和性,可以作为表位疫苗设计的候选表位。本论文尝试在戊型肝炎病毒重组衣壳蛋白的基础上阐释了戊型肝炎病毒抗原表位,筛选出具有代表性的表位并进行深入的分析比较,尝试在这些表位基础上对其表位疫苗设计进行了初步的探索。这不仅为表位的深入研究提供了方法参考和研究思路,有助于对戊型肝炎病毒抗原全面深入的了解;还有利于其病理研究和疫苗研制,对戊型肝炎病毒表位疫苗设计具有很好的参考价值。更多还原

【Abstract】 Hepatitis E Virus(HEV) has emerged to be a dominant cause of acute hepatitis, which is often associated with outbreaks and epidemics in both developing and industrialized countries.Accumulating evidence indicated that hepatitis E was a zoonotic disease.The ability of cross-species infection of HEV raised potential public health concerns for zoonotic HEV transmission which might become a great threat to human health.Researches into this pathogen were not enough to make the mechanisms of HEV replication and pathogenesis clearly understood,this was mainly due to the lack of efficient virus isolation method and cell culture system or a practical animal model.For providing better disease prevention and control program, we need very much to investigate the nature of this antigen and its immune response mechanism.In this research,a pool of anti-HEV antibodies immunized from turncated caspid proteins were fristly studied in detail.Technique used were including epitope identification based on recombinant proteins or overlapping peptide libraries,analysis of competitive inhibition of antigen-antibody reaction,RT-PCR analysis of virus immune capture and analysis of the nature of antibodies based on cell binding model of recombinant proteins which could form virus-like particle or virus-cell adsorption model.Secondly,some representative epitopes were analysised and compared by multiple alignment and mutation analysis,which could help to understand the complex HEV epitopes and be of great importance to vaccine design.Thirdly,in order to enhance the immunogenicity of epitopes,we fully display epitopes by constructing epitope fusion proteins using HBcAg virus-like particles as a vector. Serial analysis of serums from immunized BALB/c mouse demonstrated the 12A10 epitope,one non-immunodominant epitope,had the ability of neutralizing HEV nature virus.The result indicated that this epitope might serve as candidate epitope for epitope-based vaccine design. In conclusion,this thesis attempted to illuminate HEV epitopes based on reconbinant caspid proteins,analysis selected representative epitopes in more details and made a tentative research on epitope-based vaccine design.A vaccine against HEV is not yet available.Existing vaccine candidates were based on modification of HEV caspid protein,rather than epitope-based vaccine design technology.So,this research was not only helpful for in-depth study of HEV epitopes by providing some research methods,but also beneficial to pathological research and vaccine development,which had a good reference value for design of HEV epitope-based vaccine.更多还原