Immunization with glutathione S-transferase and mutant toxic shock syndrome toxin 1 fusion protein protects against Staphylococcus aureus infection

To investigate whether immunization with glutathione S-transferase (GST) and mutant toxic shock syndrome toxin 1 (mTSST-1) fusion protein can protect against Staphylococcus aureus infection, we purified a non-toxic mutant GST-mTSST-1 fusion protein. Mice were immunized with the GST-mTSST-1 plus alum adjuvant and then challenged with viable S. aureus. The results showed that the survival rate of GST-mTSST-1-immunized group was higher and the bacteria counts in the organs were significantly lower than those of the non-immunized mice. Immunization with GST-mTSST-1 induced strongly the production of TSST-1 specific antibodies, especially immunoglobulin G1 and immunoglobulin G2b. Furthermore, the serum samples from GST-mTSST-1-immunized mice also significantly inhibited interferon-gamma and tumor necrosis factor-alpha production from murine spleen cells by TSST-1. These results suggest that vaccination with GST-mTSST-1 provides protection against S. aureus infection and that the protection might be mediated by TSST-1-neutralizing antibody.