Delayed hypersensitivity to Staphylococcus aureus in mice: in vitro responses to isolated Staphylococcal antigens.

The development of delayed hypersensitivity (DH) to Staphylococcus aureus in Swiss mice was evaluated by the footpad (FP) assay. In order to determine which component of the bacteria was responsible for the in vivo immune reactivity, purified Staphylococcal cell wall, cell membrane, protein A, lipoteichoic acid, teichoic acid, as well as lipid-free membrane proteins were isolated. The immune responses of mice receiving one to eight S. aureus injections indicated that the first DH peak, following three injections, was primarily dependent upon protein antigens associated with the bacterial membrane. Increased bacterial injections gave rise to a second DH peak following seven injections which was dependent upon multiple bacterial components including cell wall, protein A, and membrane proteins.