Glycosphingolipids as Putative Receptor for Staphylococcal Enterotoxin-B inCultured Human Kidney Cells

摘要

Staphylococcal enterotoxin-B (SEB) is a common enterotoxin that can causediarrhea and death in man. In these studies we have developed a specific and sensitive assay for the detection of SEB (enzyme linked receptor-based immunodot) in human fluids, plasma and urine. Our structure/function studies have revealed that amino acid sequence (130-160) of SEB (peptide number 9) imparts toxic effects including cell death in PT cells. In addition, we found that SEB can activate neutral sphingomyelinase (N-SMase) resulting in the hydrolysis of sphingomyelin to ceramide and phosphocholine. Ceramide, in turn induces programmed cell death (apoptosis). Interestingly, several of the SEB mutants of peptide no. 9 were found to abrogate SEB toxicity in human kidney cells. Our findings will of potential value for the food industry, and to help determine toxemia in our soldiers. Such studies will also elaborate the pathophysiology of SEB induced toxemia in man.