Abstract 1556

Staphylococcal scalded skin syndrome (SSSS) is a disease of neonates, young children and rarely adults, resulting from infection with exotoxin producing Staphylococcus aureus. In adults SSSS has often been associated with an immunocompromised state or advanced age. Staphylococcal exfoliative toxin A (ETA) is one of two exfoliative toxins responsible for causing SSSS in humans. A murine model that closely resembles human SSSS in age differentiation and pathology has been established. The mechanism of protection of healthy adults infected or colonized with exfoliative toxin producing staphylococci is not clearly understood. We hypothesized that a mature adaptive immune response contributes to the protection of adults from the effects of ETA. To address this hypothesis we evaluated the response of various populations of immunocompromised adult mice and neonatal mice of increasing age to recombinant ETA (rETA) previously shown to be active in the neonatal murine model. The neonatal mice had a dramatic decrease in the ability to respond to the toxin by day of life eight. Adult mice with severe combined immune deficiency (SCID) and T cell-depleted mice were both resistant to exofoliation by the toxin in concentrations equal to, and ten fold greater than, that shown to be effective in neonatal mice at less than 7 days of life. These data support the conclusion that a mature adaptive immune response is not responsible for protection of adults exposed to rETA.