手足口病是以EV71和CA16为主的多种肠道病毒（EV）引起的常见传染病，目前缺乏临床可用疫苗。EV71和CA16表位疫苗在诱导病毒特异性免疫的同时可避免有害的免疫反应，但是如何进一步增强免疫原性和扩大免疫保护范围是其发展的关键。卡介苗是优良的多价疫苗投递工具兼高效佐剂；我们的前期工作发现，EV71和CA16的多个保守中和表位具有与多种其它EV交叉反应性潜能。本项目拟在此基础上，制备基于这些中和表位的抗体，以微量中和实验测定这些中和表位对手足口病其它病原的交叉免疫性；然后借助生物信息学工具优化EV71和CA16的型内和型间交叉反应性中和表位与通用Th细胞表位构成的融合多肽的连接组合，以卡介苗为载体构建分泌表达该融合多肽的重组卡介苗，免疫小鼠并观察该融合多肽的基因重组卡介苗诱导的免疫反应以及针对手足口病多种病原的免疫保护效率，为研制安全有效、价格低廉和易于接受的广谱性手足口病疫苗奠定基础。

Hand, foot and mouth disease (HFMD) is a common illness caused by many enteroviruses (EV), among which EV71 and CA16 are the main causative agents. No vaccine is currently available against this disease. Epitope vaccines of EV71 and CA16 can induce virus-specific immunity without autoimmunity. However, the enhanced immunogenicity and broadened protection scope are required for the epitope vaccines. Bacillus Calmette-Guerin (BCG) is an ideal multivalent vaccine vehicle and by self a potent adjuvant in experimental animals and man, and we found in the preliminary study that several conserved B-cell epitopes of EV71 and CA16 are potentially cross-reactive against a number of other EVs. In this project, we plan to validate the cross-immunity of these neutralization epitopes against other HFMD agents by a neutralization assay, and optimize the combination of intra- and inter-typic cross-protective neutralization epitopes from EV71 and CA16 and universal Th epitopes by using bioinformatics tools, and construct a recombinant BCG expressing a fusion peptide of these epitopes, and then investigate the immunological effects in mice and protective efficacy of the recombinant BCG against a variety of HFMD agents. This study will lay foundation and provide useful information for the development of a safe, effective and acceptable broad-spectrum vaccine against HFMD.