论文部分内容阅读
为研究金黄色葡萄球菌(Staphylococcus aureus)凝集因子A(ClfA)免疫原性及免疫保护作用,应用PCR方法扩增出金黄色葡萄球菌Newman、Wood46和HLJ23-1株的clfa基因并进行序列分析,再将Newman株的clfa基因插入到pQE-30载体上,导入宿主菌Escherichia coli M15(pREP4)并诱导表达和纯化ClfA重组蛋白。用纯化的ClfA免疫小鼠,检测血清中抗体和细胞因子水平,首次免疫后35 d时用金黄色葡萄球菌Wood46、HLJ23-1、Newman株对小鼠攻毒。结果发现:clfa基因序列高度保守;ClfA重组蛋白在E.coli M15中获得表达;在首次免疫后35 d时血清抗体效价和细胞因子浓度与对照组相比,均显著升高(P<0.05);攻毒结果为蛋白免疫组小鼠获得一定的免疫保护。由此表明,ClfA重组蛋白有较好的免疫原性和免疫保护力。
In order to study the immunogenicity and immunoprotection of coagulation factor A (ClfA) of Staphylococcus aureus, clfa genes of Staphylococcus aureus Newman, Wood46 and HLJ23-1 were amplified by PCR and sequenced. The clfa gene of Newman strain was inserted into pQE-30 vector and introduced into host strain Escherichia coli M15 (pREP4) to induce the expression and purification of ClfA recombinant protein. The mice were immunized with purified ClfA, and the serum levels of antibodies and cytokines were detected. The mice were challenged with Staphylococcus aureus Wood46, HLJ23-1 and Newman at 35 days after the first immunization. The results showed that the clfa gene sequence was highly conserved and the ClfA recombinant protein was expressed in E.coli M15. The serum antibody titer and cytokine concentration were significantly increased at 35 days after the first immunization compared with the control group (P <0.05 ); The results of the challenge of the protein immunized mice to obtain a certain degree of immune protection. Thus, ClfA recombinant protein has better immunogenicity and immunoprotective power.