SELECTION OF PHAGE-DISPLAYED SUPERANTIGEN BY BINDING TO CELL-SURFACE MHC CLASS-II

We have expressed the superantigen staphylococcal enterotoxin A (SEA) on the surface of bacteriophage as a fusion with the gene VIII protein (gVIIIp). This phage-displayed superantigen retains the properties in herent in the natural protein. It binds to MHC class II and activates T-cells bearing appropriate VP regions. A flexible 5-amino acid linker sequence between the SEA molecule and the phage coat protein improved the production of functional phage-displayed SEA. Binding to MHC clas s II-expressing cells effectively selected SEA-phage from non-SEA-phag e background. This indicates that this will be an effective method for selecting new specificities of superantigen from libraries of SEA mut ants and for cloning of novel superantigens.