萨奇B3 (CVB3)属肠道病毒型，是手足口病病原之一，也是引起病毒性心肌炎最常见的致病原。目前临床上没有针对CVB3感染的特效药物和疫苗。本课题运用反向遗传学技术，以近年来在我国华南地区流行的CVB3 Nancy株为载体，通过缺失病毒VP4壳蛋白基因，获得低细胞毒性重组缺陷型CVB3病毒疫苗。该重组缺陷型CVB3病毒可以感染CVB3敏感细胞，并表达具有免疫原性的病毒VP1蛋白，但因VP4蛋白缺失而无法包装出有感染性的子代病毒。本项目进一步将在重组缺陷型CVB3病毒载体中，通过引入核酸酶切位点从而表达外源目的基因，为今后重组缺陷型CVB3病毒多价疫苗的研发提供基础平台。本研究在优化免疫条件的基础上，将建立高效，简便的免疫接种途径。通过动物攻毒实验评价重组缺陷型CVB3疫苗的免疫保护效果和免疫病理损伤程度，揭示重组缺陷型CVB3疫苗引发机体免疫应答所涉及的细胞和分子免疫机制。

Coxsachievirus B3 ( CVB3 ), the enterovirus B and single strand RNA virus, is one of commom pathogens which can cause Hand-foot and mouth disease (HFMD) and viral myocarditis. At present, there is no clinical effects of drugs and vaccines against CVB3 infection. Using reverse genetics technology, a low cell toxicity of recombinant CVB3 defective virus vaccine was obtained with China CVB3 Nancy strain deleted virus VP4 capsid protein gene as the carrier. The recombinant CVB3 defective virus can infect CVB3 cells, and express immunogenic virus VP1 protein, but can not rescue infectious progeny virus. Further more, restriction endonuclease site will be inserted in the CVB3 virus for exogenous gene experssion, which could be a basis platform for the research and development of multivalent recombinant defective CVB3 virus vaccine.The study will not only constuct a simple and effective vaccinate method, but also reveal the cellular and molecular mechanism invovled in the recombinant defective CVB3 virus vaccine caused immune response, by evaluating the immune protection effect and pathology damage degree accoding to animal experiment.