Protection against Staphylococcus aureus sepsis by vaccination with recombinant staphylococcal enterotoxin A devoid of superantigenicity

Staphylococcal exotoxins are virulence determinants in Staphylococcus aureu s arthritis and septicemia. To assess the utility of enterotoxins as vaccin e candidates for these diseases, a genetically modified staphylococcal ente rotoxin A (SEA) that lacks superantigenic properties was used. Mice immuniz ed with recombinant (r) SEA had significantly longer survival than control immunized mice and lost significantly less weight than the controls, Transf er of SEA-specific antibodies to naive mice resulted in good protection aga inst death in staphylococcal sepsis, In vitro proliferative responses to SE A by naive lymphocytes were almost totally abolished on incubation with ser um from rSEA but not with control antigen-immunized mice. These results sug gest that immunization with rSEA devoid of superantigenic properties provid es good protection against S. aureus sepsis, In addition, the data indicate that the protection is at least in part mediated by SEA neutralizing antib odies.