Cross-reactive antibodies prevent the lethal effects of Staphylococcus aureus superantigens

The exotoxins produced by Staphylococcus aureus, staphylococcal enterotoxin s (SE) A-E and toxic shock syndrome toxin (TSST)-1, which are associated wi th serious diseases, including food poisoning and toxic shock syndrome, are termed superantigens (SAgs), To examine whether common antigenic epitopes were present and whether vaccination with 1 bacterial SAg could protect aga inst challenge with a different SE or TSST-1, mice were vaccinated with SEA , SEE, SEC1, or TSST-1 individually or in combination. Mice injected with a single toxin developed high antibody titers against other SAgs, Marked imp rovement in survival was observed when immunized mice were challenged with a heterologous toxin, Mice vaccinated with a mixture of toxins were fully p rotected against 1 or multiple toxin challenges, indicating no interference effects of multivalent vaccinations, More importantly, higher titers were found against each SAg with the multivalent vaccination than with injection with a single SAg, Thus, immunizations with 1 SAg can induce cross-protect ive antibodies to heterologous SAgs, and multicomponent vaccination can enh ance antibody responses against each bacterial SAg.