Abstract：
β-defensin of flounder plays an important role in immunomodulation by recruiting immune cells and has a potential vaccine adjuvant effect in addition to its bactericidal activity. In this study, adjuvant effects of β-defensin on DNA vaccine OmpC against edwardsiellosis in flounder (Paralichthys olivaceus) were investigated. The bicistronic eukaryotic expression plasmid pBudCE4.1 plasmid vector with two independent coding regions was selected to construct DNA vaccine of p-OmpC which express only the gene for the outer membrane protein of Edwardsiella tarda and the vaccine of p-OmpC-βdefensin which express both the outer membrane protein of the bacterium and β-defensin of flounder. In vitro and in vivo studies have shown that the constructed plasmids can be expressed in flounder embryonic cell lines and injection sites of muscles. After vaccination by intramuscular injection, both p-OmpC and p-OmpC-βdefensin groups showed significant upregulation of immune-response. Compared to the pBbudCE4.1 and the p-OmpC vaccinated groups, the p-OmpC-βdefensin vaccinated group showed significantly more cell aggregation at the injection site and intense immune response. The proportion of sIgM+ cells, as well as the CD4-1+ and CD4-2+ cells in both spleen and kidney was significantly higher in the p-OmpC-βdefensin vaccinated group at peak time point than in the control groups. The relative survival rate of the p-OmpC-βdefensin vaccine was 74.17%, which was significantly higher than that of the p-OmpC vaccinated group 48.33%. The results in this study determined that β-defensin enhances the responses in cellular and humoral immunity and evokes a high degree of protection against E. tarda, which is a promising candidate for vaccine adjuvant.
摘要：
比目鱼的β-防御素通过募集免疫细胞在免疫调节中起重要作用，除具有杀菌活性外，还具有潜在的疫苗佐剂作用。在这项研究中,研究了β-防御素对比目鱼（Paralichthysolivaceus）的DNA疫苗OmpC的佐剂作用。选择具有两个独立编码区的双顺反子真核表达质粒pBudCE4.1质粒载体，以构建仅表达塔氏爱德华菌外膜蛋白基因的p-OmpCDNA疫苗和同时表达的p-OmpC-β防御素疫苗。细菌的外膜蛋白和比目鱼的β-防御素。体外和体内研究表明，构建的质粒可以在比目鱼胚胎细胞系和肌肉注射部位表达。通过肌肉注射接种疫苗后，p-OmpC和p-OmpC-β防御素组均显示免疫反应的显着上调。与pBbudCE4.1和p-OmpC疫苗接种组相比，接种p-OmpC-β防御素的组在注射部位显示出明显更多的细胞聚集和强烈的免疫反应。sIgM+细胞的比例，在高峰时间点，p-OmpC-β防御素疫苗接种组的脾脏和肾脏中的CD4-1和CD4-2细胞显着高于对照组。p-OmpC-β防御素疫苗的相对存活率为74.17%,显著高于p-OmpC接种组48.33%。这项研究的结果确定，β-防御素增强了细胞和体液免疫的反应，并引起了对E.tarda的高度保护，这是一个有希望的候选疫苗佐剂。
