Superantigens combine with MHC class-II molecules to form the ligands that stimulate T
cells via the Vβ element of the T-cell receptor. Two groups of superantigens have been
described so far: first, endogenous murine products that include the MIs determinants, and
second, bacterial products such as the Staphylococcal enterotoxins. Here, we review studies
that address the interactions between the foreign superantigens and MHC class-II
molecules, the mechanism of T-cell stimulation, and the role that tolerance to self …