Comparative Immunoprotection Of Staphylococcus Aureus Recombinant Protein Trap, IsdA, IsdB, And GapC

Staphylococcus aureus (S.aureus) is an important pathogen that causes human and animal infections.S.aureus infections have been prevented and treated with antibiotics for long time. But widespread use ofantibiotics in treatment has resulted in the increasing of antibiotics-resistant S. aurues strains, which hasmade many antibiotics ineffective. So vaccination seems to be a promising approach to prevent theinfections.Previous researches have demonstrated that S. aureus proteins TraP, IsdA, IsdB and GapC showedgood imrnunogenicity. In order to compare the imrnunogenicity and immunoprotection of the proteins TraP,IsdA, IsdB and GapC, we amplified traP, isdA, isdB, gapC genes from S.aureus Newman strain, respectively.The genes from Newman strain were subsequently inserted into pQE-30vector and the recombinant plasmidswere transformed into Escherichia coli strain M15(pREP4)．The recombinant proteins were expressed andpurified. Then, we immunized mice with the purified recombinant proteins. The antibody level was measuredby enzyme-linked immunosorbent assay (ELISA). In vitro test, lymphocytes were separated from immunizedmice splenocytes and stimulated with the corresponding antigens, the frequency of cells producing IL-4orIFN-γ in the lymphocytes was measured by ELISPOT, the level of IL-17in the supernatant of cell cultureswere determined by ELISA. Finally, immunized mice were challenged with S.aureus Newman, Wood46andHLJ23-1. The results suggested that the recombinant proteins TraP, IsdA, IsdB and GapC were expressedcorrectly in E.coli M15. The antibody level and cytokines secreted by splenic lymphocytes from theimmunized groups was significantly higher than that in control group (p<0.05), and the mice immunized withTraP、GapC、IsdB show higher immune protective efficiency against the challenge strains Newman、Wood46、HLJ23-1, respectively. These results demostrate that the antigens TraP, IsdB and GapC can inducebetter immunoprotection against challenge with various S. aureus strains.