猪丹毒丝菌CbpB蛋白对小鼠的免疫效果分析

Immunogenicity Analysis and Protective Effects of CbpB Protein of Erysipelothrix rhusiopathiae in Mice

探究猪丹毒丝菌(ER)CbpB蛋白的免疫原性和保护作用,为深入研制ER基因工程亚单位疫苗提供新的思路和技术储备。以表达的ER重组蛋白CbpB、SpaA、CbpB+SpaA以及ER灭活全菌体(V-AEr21)、商品化弱毒疫苗、商品化灭活疫苗分别免疫小鼠。利用间接ELISA检测小鼠血清中IgG抗体,血清杀菌试验测定功能性抗体水平,攻毒试验测定免疫保护率,组织荷菌数试验测定ER定植情况,并采集小鼠组织脏器(脾、肺、肝、肾)制备切片,观察病理变化。结果显示:与免疫原性最优的商品化弱毒疫苗相比,CbpB和SpaA虽产生的IgG抗体均仅为1∶6400,但血清杀菌效果强;对小鼠的免疫攻毒保护率与商品化弱毒疫苗相同,均为100%,且在脾、肺、肝、肾组织中均无细菌定植,病理组织学观察与空白对照无明显区别。CbpB重组蛋白具有良好的免疫原性和保护作用,能刺激机体产生体液免疫和细胞免疫,可以作为猪丹毒基因工程亚单位疫苗的候选抗原。

This study aimed to explore the immunogenicity and protective effects of CbpB protein of Erysipelothrix rhusiopathiae, and to provide new ideas and technical reserves for the further development of ER genetic engineering subunit vaccine. Mice were immunized with the expressed ER recombinant proteins CbpB, SpaA, CbpB+SpaA, ER inactivated whole cell (V-AEr21), commercial attenuated vaccine, and commercial inactivated vaccine, respectively. Indirect ELISA was used to detect the level of IgG antibodies. The challenge test was selected to determine the immune protection rate. Tissue bacteria count test was conducted to determine ER colonization. Mouse tissue organs (spleen, lung, liver, and kidney) were collected to prepare slices and observe pathological changes. Compared with the commercial attenuated vaccine with the strongest immunogenicity, the IgG antibody produced by CbpB and SpaA was only 1:6 400, but the bactericidal efficacy of serum was high. The immune challenge protection rate of mice was the same as that of commercial attenuated vaccine, which was 100%, and there was no bacterial colonization in spleen, lung, liver and kidney, and there was no significant difference between histopathological observation and blank control. There was no difference between CbpB and SpaA. CbpB recombinant protein has good immunogenicity and protective efficacy, can stimulate the body to produce humoral immunity and cellular immunity, and can be used as a candidate antigen for swine erysipelas genetic engineering subunit vaccine.