A broad-spectrum inhibitory peptide against staphylococcal enterotoxin superantigen SEA, SEB and SEC

The family of staphylococcal enterotoxin (SE) superantigen has been known to contribute to a broad-spectrum of diseases. In an attempt to screen the peptides with broad-spectrum inhibition against the superantigen activity of SEs, nine low-molecular peptides were designed on the basis of high conservative regions of amino acid sequences and structures of the SEs, the effects of these inhibitory peptides on the biological activity of SEs were detected by cellular and animal models, competition assay was used to detect the ability of the inhibitory peptide binding to MHC class II molecules. The results indicated that one dodecapeptide P72 possessed a broad-spectrum antagonist activity against superantigen SEA, SEB and SEC. The peptide P72 could protect mice from lethal toxic shock in the "two-hit" animal model. Competition experiment demonstrated peptide P72 could not bind to MHC class II molecules, which indicated the inhibitory activity of P72 may not due to binding to MHC class II. The peptide P72 with effective inhibition against the superantigen SEA, SEB and SEC may lead to a novel therapeutic modality in treatment of superantigen-mediated diseases.