金黄色葡萄球菌黏附素ClfA,FnBPA-A,FnBPA-BCD联合免疫的免疫生物学特性

Characterization of antiserum after co-immunized with adhesins expressing Clf A,Fn BPA-A and Fn BPA-BCD of Staphylococus aureus

【目的】为比较金黄色葡萄球菌黏附素分子聚集因子(Clf A)与纤连蛋白结合蛋白A(Fn BPA)A区(Fn BPA-A)及BCD区(Fn BPA-BCD)的抗原性、抗体的黏附抑制特性及其免疫保护力。【方法】分别表达了Clf A蛋白、Fn BPA-A和Fn BPA-BCD蛋白,并将表达纯化后得到Clf A、Fn BPA-A和Fn BPA-BCD重组蛋白单独或联合免疫小鼠,收集免疫血清对其进行抗原性及免疫保护力的比较分析。【结果】结果显示,重组蛋白Fn BPA-BCD对Fn的结合能力高于其对Fg的结合,而重组蛋白Clf A及Fn BPA-A对Fg的结合能力高于Fn BPA-BCD。血清抗体的检测结果表明,Clf A蛋白及Fn BPA-A蛋白免疫组诱导抗体的水平均优于Fn BPABCD组。3种蛋白联合免疫组的血清抗体效价及抗体抗黏附能力明显优于单一蛋白免疫组(P<0.05)。3种蛋白联合免疫组与Clf A蛋白免疫组免疫保护率为100%,Fn BPA-A组与Fn BPA-BCD组免疫保护率分别为80%与50%。【结论】重组蛋白Clf A及Fn BPA-A的免疫原性优于Fn BPA-BCD,三者联合免疫较单一蛋白免疫在抗细菌的黏附、抗体诱导和免疫保护方面具有优势,提示这3种蛋白联合免疫有利于达到更好的免疫效果。

[Objective] To compare the antigenicity,adhesion inhibition activity and immune protection of the serum immunized with recombinant adhesins Clumping factor A（ Clf A）,Fibronection binding protein A-A（ Fn BPA-A） and Fibronection binding protein A-BCD（ Fn BPA-BCD） of Staphylococcus aureus. [Methods] Clf A,Fn BPA-A and Fn BPABCD genes were expressed and the resulting recombinant proteins were induced and purified. After immunizing mice with these purified proteins in combination or alone,the serum antibodies of mice were analyzed and compared for their antigenicity,adhesion inhibition activity and immune protection. [Results] The recombinant Fn BPA-BCD protein had better fibronection（ Fn） binding ability than that of fibrinogen（ Fg） binding and Clf A. Fn BPA-A had better binding capacity to Fg than that of Fn BPA-BCD. The antibody titer induced by Clf A and Fn BPA-A were better than that of Fn BPA-BCD,and three proteins co-immunization group had better antibody titer and adhesion inhibition to Staphylococcus aureus than those of single recombinant protein immunization group（ P0. 05）. The immune protection rate for both Clf A and three proteins co-immunization group were 100% and for Fn BPA-A and Fn BPA-BCD immunization group the immune protection rate were 80% and 50%,respectively. [Conclusion] Our data suggest that coimmunization with these 3recombinant proteins helps to achieve better immune effect.