酿酒酵母因具有良好安全性而作为疫苗载体已广泛应用于传染病的预防，最近，因其可靶向APCs高效递呈Ag而倍受亲睐。DNA疫苗具有生产简易、免疫应答全面、成本低等优点，但如何提高其免疫接种的靶向性尚未阐明。课题组前期研究发现，利用酿酒酵母携带克隆有流感病毒HA基因真核盒式表达结构的附加质粒，免疫小鼠后获得了一定的免疫应答和保护效果。因此，我们推测利用酿酒酵母可获得靶向性递呈和表达的DNA疫苗。为证实这一假设，课题组拟在前期研究结果基础上，以HA为目的基因验证其在体外被APCs摄取的效果，初步为探讨廉价、安全、靶向性的新型DNA疫苗生产模式提供重要的理论基础和参考价值。

Saccharomyces cerevisiae has been widely used as a vaccine vector in infectious diseases due to its graeat security. Recently, more and more researchs focused on Saccharomyces cerevisiae because it can efficiently present Ag gene to APCs. DNA vaccine is popular because of its advantages, such as easy production, induction of comprehensive immune response and low cost. But how to improve the DNA vaccine immunization targeting and the mechanism haven't been elucidated. Our prepared studies showed mice immunized with Saccharomyces cerevisiae containing episomal plasmid expressing influenza virus HA gene with CMV promoter obtained immune response and protective effect against to influenza virus. We speculate that the DNA vaccine presented by Saccharomyces cerevisiae can achieve the targeted presentation and expression DNA vaccine. To verify this hypothesis, we will evaluate the efficiency that the Saccharomyces cerevisiae strain with HA gene episomal plasmid was captured by APCs. Based on the evaluation, we will explore the feasibility of constructing high efficient DNA complexed Saccharomyces cerevisiae and explore the theoretical basis and reference value of cheap, safe, targeted DNA vaccine.