[Characterization of antiserum after co-immunized with adhesins expressing ClfA, FnBPA-A and FnBPA-BCD of Staphylococus aureus].

ABSTRACT

OBJECTIVE: To compare the antigenicity, adhesion inhibition activity and immune protection of the serum immunized with recombinant adhesins Clumping factor A (CfA), Fibronection binding protein A-A ( FnBPA-A) and Fibronection binding protein A-BCD (FnBPA-BCD) of Staphylococcus aureus. METHODS: ClfA, FnBPA-A and FnBPA-BCD 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 FnBPA-BCD protein had better fibronection (Fn) binding ability than that of fibrinogen (Fg) binding and ClfA. FnBPA-A had better binding capacity to Fg than that of FnBPA-BCD. The antibody titer induced by ClfA and FnBPA-A were better than that of FnBPA-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 (P < 0.05). The immune protection rate for both ClfA and three proteins co-immunization group were 100% and for FnBPA-A and FnBPA-BCD immunization group the immune protection rate were 80% and 50%, respectively. CONCLUSION: Our data suggest that coimmunization with these 3 recombinant proteins helps to achieve better immune effect.