Identification of toxicity and efficacy against new staphylococcal enterotoxin B subunit vaccine

Abstract

Abstract Staphylococcus aureus (S. aureus) bacteria, the gram-positive coccus and occurring irregular clusters, have the power to produce many types of enterotoxin. It is known as a foodborne poisoning agent as well as being a potential inhaled bioterrorism agent. Previously we confirmed the structure of modified-S. aureus enterotoxin B (SEB) vaccine candidate (ABN701) that can induce neutralization of antigen activity and also elicit humoral and cellular immune response. In this study, we studied the immunization efficacy and toxicity of ABN701 in various animal models. ABN701 was immunized in a dose dependent manner to BalB/C mouse and rabbit and about 20 ug ABN701 can induce an immune response in these models. Through the adjuvant tests, aluminum-composed adjuvant triggered more antibody inducement in mice and rabbit. The immunized BalB/C mouse were challenged with the SEB toxin and survived against 20LD50 SEB toxin treatment. Emesis is one of the most important evaluation factors for SEB vaccine development because emesis is related to SEB toxin symptom. House musk shrew mouse (Suncus Murinus) is widely known to be sensitive to various emetic drug evaluation and a new experimental animal model for SEB toxin related emesis. We confirmed that ABN701 did not cause emesis while SEB toxin cause emesis in this model. We also immunized ABN701 to monkey and showed no emesis symptom, but induced an effective immune response. In this study, we identified that ABN701 can induce an immune response in mouse, rabbit and monkey and ABN701 do not have toxicity related to emesis in the House musk shrew mouse model and monkey model.